summaryrefslogtreecommitdiff
path: root/shell/hush.c
blob: 47e53f8c1a1e07dbeb7584ef5be493210add67c5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
/* vi: set sw=4 ts=4: */
/*
 * sh.c -- a prototype Bourne shell grammar parser
 *      Intended to follow the original Thompson and Ritchie
 *      "small and simple is beautiful" philosophy, which
 *      incidentally is a good match to today's BusyBox.
 *
 * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
 *
 * Credits:
 *      The parser routines proper are all original material, first
 *      written Dec 2000 and Jan 2001 by Larry Doolittle.  The
 *      execution engine, the builtins, and much of the underlying
 *      support has been adapted from busybox-0.49pre's lash, which is
 *      Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *      written by Erik Andersen <andersen@codepoet.org>.  That, in turn,
 *      is based in part on ladsh.c, by Michael K. Johnson and Erik W.
 *      Troan, which they placed in the public domain.  I don't know
 *      how much of the Johnson/Troan code has survived the repeated
 *      rewrites.
 *
 * Other credits:
 *      o_addchr() derived from similar w_addchar function in glibc-2.2.
 *      setup_redirect(), redirect_opt_num(), and big chunks of main()
 *      and many builtins derived from contributions by Erik Andersen
 *      miscellaneous bugfixes from Matt Kraai.
 *
 * There are two big (and related) architecture differences between
 * this parser and the lash parser.  One is that this version is
 * actually designed from the ground up to understand nearly all
 * of the Bourne grammar.  The second, consequential change is that
 * the parser and input reader have been turned inside out.  Now,
 * the parser is in control, and asks for input as needed.  The old
 * way had the input reader in control, and it asked for parsing to
 * take place as needed.  The new way makes it much easier to properly
 * handle the recursion implicit in the various substitutions, especially
 * across continuation lines.
 *
 * Bash grammar not implemented: (how many of these were in original sh?)
 *      $_
 *      &> and >& redirection of stdout+stderr
 *      Brace Expansion
 *      Tilde Expansion
 *      fancy forms of Parameter Expansion
 *      aliases
 *      Arithmetic Expansion
 *      <(list) and >(list) Process Substitution
 *      reserved words: case, esac, select, function
 *      Here Documents ( << word )
 *      Functions
 * Major bugs:
 *      job handling woefully incomplete and buggy (improved --vda)
 *      reserved word execution woefully incomplete and buggy
 * to-do:
 *      port selected bugfixes from post-0.49 busybox lash - done?
 *      change { and } from special chars to reserved words
 *      builtins: break, continue, eval, return, set, trap, ulimit
 *      test magic exec
 *      check setting of global_argc and global_argv
 *      follow IFS rules more precisely, including update semantics
 *      figure out what to do with backslash-newline
 *      propagate syntax errors, die on resource errors?
 *      continuation lines, both explicit and implicit - done?
 *      memory leak finding and plugging - done?
 *      maybe change charmap[] to use 2-bit entries
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */


#include <glob.h>      /* glob, of course */
/* #include <dmalloc.h> */

#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */

// TEMP
#define ENABLE_HUSH_CASE 0


#if !BB_MMU && ENABLE_HUSH_TICK
//#undef ENABLE_HUSH_TICK
//#define ENABLE_HUSH_TICK 0
#warning On NOMMU, hush command substitution is dangerous.
#warning Dont use it for commands which produce lots of output.
#warning For more info see shell/hush.c, generate_stream_from_list().
#endif

#if !BB_MMU && ENABLE_HUSH_JOB
#undef ENABLE_HUSH_JOB
#define ENABLE_HUSH_JOB 0
#endif

#if !ENABLE_HUSH_INTERACTIVE
#undef ENABLE_FEATURE_EDITING
#define ENABLE_FEATURE_EDITING 0
#undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
#define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
#endif


/* If you comment out one of these below, it will be #defined later
 * to perform debug printfs to stderr: */
#define debug_printf(...)        do {} while (0)
/* Finer-grained debug switches */
#define debug_printf_parse(...)  do {} while (0)
#define debug_print_tree(a, b)   do {} while (0)
#define debug_printf_exec(...)   do {} while (0)
#define debug_printf_jobs(...)   do {} while (0)
#define debug_printf_expand(...) do {} while (0)
#define debug_printf_glob(...)   do {} while (0)
#define debug_printf_list(...)   do {} while (0)
#define debug_printf_subst(...)  do {} while (0)
#define debug_printf_clean(...)  do {} while (0)

#ifndef debug_printf
#define debug_printf(...) fprintf(stderr, __VA_ARGS__)
#endif

#ifndef debug_printf_parse
#define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
#endif

#ifndef debug_printf_exec
#define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
#endif

#ifndef debug_printf_jobs
#define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_JOBS 1
#else
#define DEBUG_JOBS 0
#endif

#ifndef debug_printf_expand
#define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_EXPAND 1
#else
#define DEBUG_EXPAND 0
#endif

#ifndef debug_printf_glob
#define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_GLOB 1
#else
#define DEBUG_GLOB 0
#endif

#ifndef debug_printf_list
#define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
#endif

#ifndef debug_printf_subst
#define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
#endif

#ifndef debug_printf_clean
/* broken, of course, but OK for testing */
static const char *indenter(int i)
{
	static const char blanks[] ALIGN1 =
		"                                    ";
	return &blanks[sizeof(blanks) - i - 1];
}
#define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_CLEAN 1
#endif

#if DEBUG_EXPAND
static void debug_print_strings(const char *prefix, char **vv)
{
	fprintf(stderr, "%s:\n", prefix);
	while (*vv)
		fprintf(stderr, " '%s'\n", *vv++);
}
#else
#define debug_print_strings(prefix, vv) ((void)0)
#endif

/*
 * Leak hunting. Use hush_leaktool.sh for post-processing.
 */
#ifdef FOR_HUSH_LEAKTOOL
/* suppress "warning: no previous prototype..." */
void *xxmalloc(int lineno, size_t size);
void *xxrealloc(int lineno, void *ptr, size_t size);
char *xxstrdup(int lineno, const char *str);
void xxfree(void *ptr);
void *xxmalloc(int lineno, size_t size)
{
	void *ptr = xmalloc((size + 0xff) & ~0xff);
	fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
	return ptr;
}
void *xxrealloc(int lineno, void *ptr, size_t size)
{
	ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
	fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
	return ptr;
}
char *xxstrdup(int lineno, const char *str)
{
	char *ptr = xstrdup(str);
	fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
	return ptr;
}
void xxfree(void *ptr)
{
	fprintf(stderr, "free %p\n", ptr);
	free(ptr);
}
#define xmalloc(s)     xxmalloc(__LINE__, s)
#define xrealloc(p, s) xxrealloc(__LINE__, p, s)
#define xstrdup(s)     xxstrdup(__LINE__, s)
#define free(p)        xxfree(p)
#endif


/* Keep unconditionally on for now */
#define HUSH_DEBUG 1
/* Do we support ANY keywords? */
#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
#define HAS_KEYWORDS 1
#define IF_HAS_KEYWORDS(...) __VA_ARGS__
#define IF_HAS_NO_KEYWORDS(...)
#else
#define HAS_KEYWORDS 0
#define IF_HAS_KEYWORDS(...)
#define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
#endif


#define SPECIAL_VAR_SYMBOL       3
#define PARSEFLAG_EXIT_FROM_LOOP 1

typedef enum {
	REDIRECT_INPUT     = 1,
	REDIRECT_OVERWRITE = 2,
	REDIRECT_APPEND    = 3,
	REDIRECT_HEREIS    = 4,
	REDIRECT_IO        = 5
} redir_type;

/* The descrip member of this structure is only used to make
 * debugging output pretty */
static const struct {
	int mode;
	signed char default_fd;
	char descrip[3];
} redir_table[] = {
	{ 0,                         0, "()" },
	{ O_RDONLY,                  0, "<"  },
	{ O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
	{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
	{ O_RDONLY,                 -1, "<<" },
	{ O_RDWR,                    1, "<>" }
};

typedef enum {
	PIPE_SEQ = 1,
	PIPE_AND = 2,
	PIPE_OR  = 3,
	PIPE_BG  = 4,
} pipe_style;

typedef enum {
	RES_NONE  = 0,
#if ENABLE_HUSH_IF
	RES_IF    ,
	RES_THEN  ,
	RES_ELIF  ,
	RES_ELSE  ,
	RES_FI    ,
#endif
#if ENABLE_HUSH_LOOPS
	RES_FOR   ,
	RES_WHILE ,
	RES_UNTIL ,
	RES_DO    ,
	RES_DONE  ,
	RES_IN    ,
#endif
#if ENABLE_HUSH_CASE
	RES_CASE  ,
	/* two pseudo-keywords support contrived "case" syntax: */
	RES_MATCH , /* "word)" */
	RES_CASEI , /* "this command is inside CASE" */
	RES_ESAC  ,
#endif
	RES_XXXX  ,
	RES_SNTX
} reserved_style;

/* This holds pointers to the various results of parsing */
struct p_context {
	struct child_prog *child;
	struct pipe *list_head;
	struct pipe *pipe;
	struct redir_struct *pending_redirect;
#if HAS_KEYWORDS
	smallint ctx_res_w;
	smallint ctx_inverted; /* "! cmd | cmd" */
#if ENABLE_HUSH_CASE
	smallint ctx_dsemicolon; /* ";;" seen */
#endif
	int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
	struct p_context *stack;
#endif
};

struct redir_struct {
	struct redir_struct *next;
	char *rd_filename;          /* filename */
	int fd;                     /* file descriptor being redirected */
	int dup;                    /* -1, or file descriptor being duplicated */
	smallint /*enum redir_type*/ rd_type;
};

struct child_prog {
	pid_t pid;                  /* 0 if exited */
	smallint is_stopped;        /* is the program currently running? */
	smallint subshell;          /* flag, non-zero if group must be forked */
	char **argv;                /* program name and arguments */
	struct pipe *group;         /* if non-NULL, first in group or subshell */
	struct redir_struct *redirects; /* I/O redirections */
	struct pipe *family;        /* pointer back to the child's parent pipe */
};
/* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
 * and on execution these are substituted with their values.
 * Substitution can make _several_ words out of one argv[n]!
 * Example: argv[0]=='.^C*^C.' here: echo .$*.
 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
 */

struct pipe {
	struct pipe *next;
	int num_progs;              /* total number of programs in job */
	int alive_progs;            /* number of programs running (not exited) */
	int stopped_progs;          /* number of programs alive, but stopped */
#if ENABLE_HUSH_JOB
	int jobid;                  /* job number */
	pid_t pgrp;                 /* process group ID for the job */
	char *cmdtext;              /* name of job */
#endif
	struct child_prog *progs;   /* array of commands in pipe */
	smallint followup;          /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
	IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
	IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
};

/* On program start, environ points to initial environment.
 * putenv adds new pointers into it, unsetenv removes them.
 * Neither of these (de)allocates the strings.
 * setenv allocates new strings in malloc space and does putenv,
 * and thus setenv is unusable (leaky) for shell's purposes */
#define setenv(...) setenv_is_leaky_dont_use()
struct variable {
	struct variable *next;
	char *varstr;        /* points to "name=" portion */
	int max_len;         /* if > 0, name is part of initial env; else name is malloced */
	smallint flg_export; /* putenv should be done on this var */
	smallint flg_read_only;
};

typedef struct {
	char *data;
	int length; /* position where data is appended */
	int maxlen;
	/* Misnomer! it's not "quoting", it's "protection against globbing"!
	 * (by prepending \ to *, ?, [ and to \ too) */
	smallint o_quote;
	smallint o_glob;
	smallint nonnull;
	smallint has_empty_slot;
	smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
} o_string;
enum {
	MAYBE_ASSIGNMENT = 0,
	DEFINITELY_ASSIGNMENT = 1,
	NOT_ASSIGNMENT = 2,
};
/* Used for initialization: o_string foo = NULL_O_STRING; */
#define NULL_O_STRING { NULL }

/* I can almost use ordinary FILE *.  Is open_memstream() universally
 * available?  Where is it documented? */
struct in_str {
	const char *p;
	/* eof_flag=1: last char in ->p is really an EOF */
	char eof_flag; /* meaningless if ->p == NULL */
	char peek_buf[2];
#if ENABLE_HUSH_INTERACTIVE
	smallint promptme;
	smallint promptmode; /* 0: PS1, 1: PS2 */
#endif
	FILE *file;
	int (*get) (struct in_str *);
	int (*peek) (struct in_str *);
};
#define i_getch(input) ((input)->get(input))
#define i_peek(input) ((input)->peek(input))

enum {
	CHAR_ORDINARY           = 0,
	CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
	CHAR_IFS                = 2, /* treated as ordinary if quoted */
	CHAR_SPECIAL            = 3, /* example: $ */
};

#define HUSH_VER_STR "0.02"

/* "Globals" within this file */

/* Sorted roughly by size (smaller offsets == smaller code) */
struct globals {
#if ENABLE_HUSH_INTERACTIVE
	/* 'interactive_fd' is a fd# open to ctty, if we have one
	 * _AND_ if we decided to act interactively */
	int interactive_fd;
	const char *PS1;
	const char *PS2;
#endif
#if ENABLE_FEATURE_EDITING
	line_input_t *line_input_state;
#endif
	pid_t root_pid;
#if ENABLE_HUSH_JOB
	int run_list_level;
	pid_t saved_task_pgrp;
	pid_t saved_tty_pgrp;
	int last_jobid;
	struct pipe *job_list;
	struct pipe *toplevel_list;
	smallint ctrl_z_flag;
#endif
	smallint fake_mode;
	/* these three support $?, $#, and $1 */
	char **global_argv;
	int global_argc;
	int last_return_code;
	const char *ifs;
	const char *cwd;
	unsigned last_bg_pid;
	struct variable *top_var; /* = &shell_ver (set in main()) */
	struct variable shell_ver;
#if ENABLE_FEATURE_SH_STANDALONE
	struct nofork_save_area nofork_save;
#endif
#if ENABLE_HUSH_JOB
	sigjmp_buf toplevel_jb;
#endif
	unsigned char charmap[256];
	char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
};

#define G (*ptr_to_globals)

#if !ENABLE_HUSH_INTERACTIVE
enum { interactive_fd = 0 };
#endif
#if !ENABLE_HUSH_JOB
enum { run_list_level = 0 };
#endif

#if ENABLE_HUSH_INTERACTIVE
#define interactive_fd   (G.interactive_fd  )
#define PS1              (G.PS1             )
#define PS2              (G.PS2             )
#endif
#if ENABLE_FEATURE_EDITING
#define line_input_state (G.line_input_state)
#endif
#define root_pid         (G.root_pid        )
#if ENABLE_HUSH_JOB
#define run_list_level   (G.run_list_level  )
#define saved_task_pgrp  (G.saved_task_pgrp )
#define saved_tty_pgrp   (G.saved_tty_pgrp  )
#define last_jobid       (G.last_jobid      )
#define job_list         (G.job_list        )
#define toplevel_list    (G.toplevel_list   )
#define toplevel_jb      (G.toplevel_jb     )
#define ctrl_z_flag      (G.ctrl_z_flag     )
#endif /* JOB */
#define global_argv      (G.global_argv     )
#define global_argc      (G.global_argc     )
#define last_return_code (G.last_return_code)
#define ifs              (G.ifs             )
#define fake_mode        (G.fake_mode       )
#define cwd              (G.cwd             )
#define last_bg_pid      (G.last_bg_pid     )
#define top_var          (G.top_var         )
#define shell_ver        (G.shell_ver       )
#if ENABLE_FEATURE_SH_STANDALONE
#define nofork_save      (G.nofork_save     )
#endif
#if ENABLE_HUSH_JOB
#define toplevel_jb      (G.toplevel_jb     )
#endif
#define charmap          (G.charmap         )
#define user_input_buf   (G.user_input_buf  )
#define INIT_G() do { \
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)


#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"

#if 1
/* Normal */
static void syntax(const char *msg)
{
	/* Was using fancy stuff:
	 * (interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
	 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
	void FAST_FUNC (*fp)(const char *s, ...);

	fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
	fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
}

#else
/* Debug */
static void syntax_lineno(int line)
{
	void FAST_FUNC (*fp)(const char *s, ...);

	fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
	fp("syntax error hush.c:%d", line);
}
#define syntax(str) syntax_lineno(__LINE__)
#endif

/* Index of subroutines: */
/*  in_str manipulations: */
static int static_get(struct in_str *i);
static int static_peek(struct in_str *i);
static int file_get(struct in_str *i);
static int file_peek(struct in_str *i);
static void setup_file_in_str(struct in_str *i, FILE *f);
static void setup_string_in_str(struct in_str *i, const char *s);
/*  "run" the final data structures: */
#if !defined(DEBUG_CLEAN)
#define free_pipe_list(head, indent) free_pipe_list(head)
#define free_pipe(pi, indent)        free_pipe(pi)
#endif
static int free_pipe_list(struct pipe *head, int indent);
static int free_pipe(struct pipe *pi, int indent);
/*  really run the final data structures: */
static int setup_redirects(struct child_prog *prog, int squirrel[]);
static int run_list(struct pipe *pi);
#if BB_MMU
#define pseudo_exec_argv(ptrs2free, argv)  pseudo_exec_argv(argv)
#define      pseudo_exec(ptrs2free, child)      pseudo_exec(child)
#endif
static void pseudo_exec_argv(char **ptrs2free, char **argv) NORETURN;
static void pseudo_exec(char **ptrs2free, struct child_prog *child) NORETURN;
static int run_pipe(struct pipe *pi);
/*   data structure manipulation: */
static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
static void initialize_context(struct p_context *ctx);
static int done_word(o_string *dest, struct p_context *ctx);
static int done_command(struct p_context *ctx);
static void done_pipe(struct p_context *ctx, pipe_style type);
/*   primary string parsing: */
static int redirect_dup_num(struct in_str *input);
static int redirect_opt_num(o_string *o);
#if ENABLE_HUSH_TICK
static int process_command_subs(o_string *dest,
		struct in_str *input, const char *subst_end);
#endif
static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
static const char *lookup_param(const char *src);
static int handle_dollar(o_string *dest,
		struct in_str *input);
static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
/*   setup: */
static int parse_and_run_stream(struct in_str *inp, int parse_flag);
static int parse_and_run_string(const char *s, int parse_flag);
static int parse_and_run_file(FILE *f);
/*   job management: */
static int checkjobs(struct pipe* fg_pipe);
#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
static void insert_bg_job(struct pipe *pi);
static void remove_bg_job(struct pipe *pi);
static void delete_finished_bg_job(struct pipe *pi);
#else
int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
#endif
/*     local variable support */
static char **expand_strvec_to_strvec(char **argv);
/* used for eval */
static char *expand_strvec_to_string(char **argv);
/* used for expansion of right hand of assignments */
static char *expand_string_to_string(const char *str);
static struct variable *get_local_var(const char *name);
static int set_local_var(char *str, int flg_export);
static void unset_local_var(const char *name);


static int glob_needed(const char *s)
{
	while (*s) {
		if (*s == '\\')
			s++;
		if (*s == '*' || *s == '[' || *s == '?')
			return 1;
		s++;
	}
	return 0;
}

static int is_assignment(const char *s)
{
	if (!s || !isalpha(*s))
		return 0;
	s++;
	while (isalnum(*s) || *s == '_')
		s++;
	return *s == '=';
}

/* Replace each \x with x in place, return ptr past NUL. */
static char *unbackslash(char *src)
{
	char *dst = src;
	while (1) {
		if (*src == '\\')
			src++;
		if ((*dst++ = *src++) == '\0')
			break;
	}
	return dst;
}

static char **add_malloced_strings_to_strings(char **strings, char **add)
{
	int i;
	unsigned count1;
	unsigned count2;
	char **v;

	v = strings;
	count1 = 0;
	if (v) {
		while (*v) {
			count1++;
			v++;
		}
	}
	count2 = 0;
	v = add;
	while (*v) {
		count2++;
		v++;
	}
	v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
	v[count1 + count2] = NULL;
	i = count2;
	while (--i >= 0)
		v[count1 + i] = add[i];
	return v;
}

static char **add_malloced_string_to_strings(char **strings, char *add)
{
	char *v[2];

	v[0] = add;
	v[1] = NULL;

	return add_malloced_strings_to_strings(strings, v);
}

static void free_strings(char **strings)
{
	if (strings) {
		char **v = strings;
		while (*v)
			free(*v++);
		free(strings);
	}
}

#if !BB_MMU
#define EXTRA_PTRS 5 /* 1 for NULL, 1 for args, 3 for paranoid reasons */
static char **alloc_ptrs(char **argv)
{
	char **v = argv;
	while (*v)
		v++;
	return xzalloc((v - argv + EXTRA_PTRS) * sizeof(v[0]));
}
#endif


/* Function prototypes for builtins */
static int builtin_cd(char **argv);
static int builtin_echo(char **argv);
static int builtin_eval(char **argv);
static int builtin_exec(char **argv);
static int builtin_exit(char **argv);
static int builtin_export(char **argv);
#if ENABLE_HUSH_JOB
static int builtin_fg_bg(char **argv);
static int builtin_jobs(char **argv);
#endif
#if ENABLE_HUSH_HELP
static int builtin_help(char **argv);
#endif
static int builtin_pwd(char **argv);
static int builtin_read(char **argv);
static int builtin_test(char **argv);
static int builtin_true(char **argv);
static int builtin_set(char **argv);
static int builtin_shift(char **argv);
static int builtin_source(char **argv);
static int builtin_umask(char **argv);
static int builtin_unset(char **argv);
//static int builtin_not_written(char **argv);

/* Table of built-in functions.  They can be forked or not, depending on
 * context: within pipes, they fork.  As simple commands, they do not.
 * When used in non-forking context, they can change global variables
 * in the parent shell process.  If forked, of course they cannot.
 * For example, 'unset foo | whatever' will parse and run, but foo will
 * still be set at the end. */
struct built_in_command {
	const char *cmd;
	int (*function)(char **argv);
#if ENABLE_HUSH_HELP
	const char *descr;
#define BLTIN(cmd, func, help) { cmd, func, help }
#else
#define BLTIN(cmd, func, help) { cmd, func }
#endif
};

/* For now, echo and test are unconditionally enabled.
 * Maybe make it configurable? */
static const struct built_in_command bltins[] = {
	BLTIN("."     , builtin_source, "Run commands in a file"),
	BLTIN(":"     , builtin_true, "No-op"),
	BLTIN("["     , builtin_test, "Test condition"),
	BLTIN("[["    , builtin_test, "Test condition"),
#if ENABLE_HUSH_JOB
	BLTIN("bg"    , builtin_fg_bg, "Resume a job in the background"),
#endif
//	BLTIN("break" , builtin_not_written, "Exit for, while or until loop"),
	BLTIN("cd"    , builtin_cd, "Change directory"),
//	BLTIN("continue", builtin_not_written, "Continue for, while or until loop"),
	BLTIN("echo"  , builtin_echo, "Write strings to stdout"),
	BLTIN("eval"  , builtin_eval, "Construct and run shell command"),
	BLTIN("exec"  , builtin_exec, "Execute command, don't return to shell"),
	BLTIN("exit"  , builtin_exit, "Exit"),
	BLTIN("export", builtin_export, "Set environment variable"),
#if ENABLE_HUSH_JOB
	BLTIN("fg"    , builtin_fg_bg, "Bring job into the foreground"),
	BLTIN("jobs"  , builtin_jobs, "List active jobs"),
#endif
	BLTIN("pwd"   , builtin_pwd, "Print current directory"),
	BLTIN("read"  , builtin_read, "Input environment variable"),
//	BLTIN("return", builtin_not_written, "Return from a function"),
	BLTIN("set"   , builtin_set, "Set/unset shell local variables"),
	BLTIN("shift" , builtin_shift, "Shift positional parameters"),
//	BLTIN("trap"  , builtin_not_written, "Trap signals"),
	BLTIN("test"  , builtin_test, "Test condition"),
//	BLTIN("ulimit", builtin_not_written, "Control resource limits"),
	BLTIN("umask" , builtin_umask, "Set file creation mask"),
	BLTIN("unset" , builtin_unset, "Unset environment variable"),
#if ENABLE_HUSH_HELP
	BLTIN("help"  , builtin_help, "List shell built-in commands"),
#endif
};


/* Signals are grouped, we handle them in batches */
static void set_misc_sighandler(void (*handler)(int))
{
	bb_signals(0
		+ (1 << SIGINT)
		+ (1 << SIGQUIT)
		+ (1 << SIGTERM)
		, handler);
}

#if ENABLE_HUSH_JOB

static void set_fatal_sighandler(void (*handler)(int))
{
	bb_signals(0
		+ (1 << SIGILL)
		+ (1 << SIGTRAP)
		+ (1 << SIGABRT)
		+ (1 << SIGFPE)
		+ (1 << SIGBUS)
		+ (1 << SIGSEGV)
	/* bash 3.2 seems to handle these just like 'fatal' ones */
		+ (1 << SIGHUP)
		+ (1 << SIGPIPE)
		+ (1 << SIGALRM)
		, handler);
}
static void set_jobctrl_sighandler(void (*handler)(int))
{
	bb_signals(0
		+ (1 << SIGTSTP)
		+ (1 << SIGTTIN)
		+ (1 << SIGTTOU)
		, handler);
}
/* SIGCHLD is special and handled separately */

static void set_every_sighandler(void (*handler)(int))
{
	set_fatal_sighandler(handler);
	set_jobctrl_sighandler(handler);
	set_misc_sighandler(handler);
	signal(SIGCHLD, handler);
}

static void handler_ctrl_c(int sig UNUSED_PARAM)
{
	debug_printf_jobs("got sig %d\n", sig);
// as usual we can have all kinds of nasty problems with leaked malloc data here
	siglongjmp(toplevel_jb, 1);
}

static void handler_ctrl_z(int sig UNUSED_PARAM)
{
	pid_t pid;

	debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
	pid = fork();
	if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
		return;
	ctrl_z_flag = 1;
	if (!pid) { /* child */
		if (ENABLE_HUSH_JOB)
			die_sleep = 0; /* let nofork's xfuncs die */
		setpgrp();
		debug_printf_jobs("set pgrp for child %d ok\n", getpid());
		set_every_sighandler(SIG_DFL);
		raise(SIGTSTP); /* resend TSTP so that child will be stopped */
		debug_printf_jobs("returning in child\n");
		/* return to nofork, it will eventually exit now,
		 * not return back to shell */
		return;
	}
	/* parent */
	/* finish filling up pipe info */
	toplevel_list->pgrp = pid; /* child is in its own pgrp */
	toplevel_list->progs[0].pid = pid;
	/* parent needs to longjmp out of running nofork.
	 * we will "return" exitcode 0, with child put in background */
// as usual we can have all kinds of nasty problems with leaked malloc data here
	debug_printf_jobs("siglongjmp in parent\n");
	siglongjmp(toplevel_jb, 1);
}

/* Restores tty foreground process group, and exits.
 * May be called as signal handler for fatal signal
 * (will faithfully resend signal to itself, producing correct exit state)
 * or called directly with -EXITCODE.
 * We also call it if xfunc is exiting. */
static void sigexit(int sig) NORETURN;
static void sigexit(int sig)
{
	/* Disable all signals: job control, SIGPIPE, etc. */
	sigprocmask_allsigs(SIG_BLOCK);

	if (interactive_fd)
		tcsetpgrp(interactive_fd, saved_tty_pgrp);

	/* Not a signal, just exit */
	if (sig <= 0)
		_exit(- sig);

	kill_myself_with_sig(sig); /* does not return */
}

/* Restores tty foreground process group, and exits. */
static void hush_exit(int exitcode) NORETURN;
static void hush_exit(int exitcode)
{
	fflush(NULL); /* flush all streams */
	sigexit(- (exitcode & 0xff));
}

#else /* !JOB */

#define set_fatal_sighandler(handler)   ((void)0)
#define set_jobctrl_sighandler(handler) ((void)0)
#define hush_exit(e)                    exit(e)

#endif /* JOB */


static const char *set_cwd(void)
{
	if (cwd == bb_msg_unknown)
		cwd = NULL;     /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
	cwd = xrealloc_getcwd_or_warn((char *)cwd);
	if (!cwd)
		cwd = bb_msg_unknown;
	return cwd;
}


/*
 * o_string support
 */
#define B_CHUNK  (32 * sizeof(char*))

static void o_reset(o_string *o)
{
	o->length = 0;
	o->nonnull = 0;
	if (o->data)
		o->data[0] = '\0';
}

static void o_free(o_string *o)
{
	free(o->data);
	memset(o, 0, sizeof(*o));
}

static void o_grow_by(o_string *o, int len)
{
	if (o->length + len > o->maxlen) {
		o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
		o->data = xrealloc(o->data, 1 + o->maxlen);
	}
}

static void o_addchr(o_string *o, int ch)
{
	debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
	o_grow_by(o, 1);
	o->data[o->length] = ch;
	o->length++;
	o->data[o->length] = '\0';
}

static void o_addstr(o_string *o, const char *str, int len)
{
	o_grow_by(o, len);
	memcpy(&o->data[o->length], str, len);
	o->length += len;
	o->data[o->length] = '\0';
}

static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
{
	while (len) {
		o_addchr(o, *str);
		if (*str++ == '\\'
		 && (*str != '*' && *str != '?' && *str != '[')
		) {
			o_addchr(o, '\\');
		}
		len--;
	}
}

/* My analysis of quoting semantics tells me that state information
 * is associated with a destination, not a source.
 */
static void o_addqchr(o_string *o, int ch)
{
	int sz = 1;
	if (strchr("*?[\\", ch)) {
		sz++;
		o->data[o->length] = '\\';
		o->length++;
	}
	o_grow_by(o, sz);
	o->data[o->length] = ch;
	o->length++;
	o->data[o->length] = '\0';
}

static void o_addQchr(o_string *o, int ch)
{
	int sz = 1;
	if (o->o_quote && strchr("*?[\\", ch)) {
		sz++;
		o->data[o->length] = '\\';
		o->length++;
	}
	o_grow_by(o, sz);
	o->data[o->length] = ch;
	o->length++;
	o->data[o->length] = '\0';
}

static void o_addQstr(o_string *o, const char *str, int len)
{
	if (!o->o_quote) {
		o_addstr(o, str, len);
		return;
	}
	while (len) {
		char ch;
		int sz;
		int ordinary_cnt = strcspn(str, "*?[\\");
		if (ordinary_cnt > len) /* paranoia */
			ordinary_cnt = len;
		o_addstr(o, str, ordinary_cnt);
		if (ordinary_cnt == len)
			return;
		str += ordinary_cnt;
		len -= ordinary_cnt + 1; /* we are processing + 1 char below */

		ch = *str++;
		sz = 1;
		if (ch) { /* it is necessarily one of "*?[\\" */
			sz++;
			o->data[o->length] = '\\';
			o->length++;
		}
		o_grow_by(o, sz);
		o->data[o->length] = ch;
		o->length++;
		o->data[o->length] = '\0';
	}
}

/* A special kind of o_string for $VAR and `cmd` expansion.
 * It contains char* list[] at the beginning, which is grown in 16 element
 * increments. Actual string data starts at the next multiple of 16 * (char*).
 * list[i] contains an INDEX (int!) into this string data.
 * It means that if list[] needs to grow, data needs to be moved higher up
 * but list[i]'s need not be modified.
 * NB: remembering how many list[i]'s you have there is crucial.
 * o_finalize_list() operation post-processes this structure - calculates
 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
 */
#if DEBUG_EXPAND || DEBUG_GLOB
static void debug_print_list(const char *prefix, o_string *o, int n)
{
	char **list = (char**)o->data;
	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
	int i = 0;
	fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
			prefix, list, n, string_start, o->length, o->maxlen);
	while (i < n) {
		fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
				o->data + (int)list[i] + string_start,
				o->data + (int)list[i] + string_start);
		i++;
	}
	if (n) {
		const char *p = o->data + (int)list[n - 1] + string_start;
		fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data);
	}
}
#else
#define debug_print_list(prefix, o, n) ((void)0)
#endif

/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
 * in list[n] so that it points past last stored byte so far.
 * It returns n+1. */
static int o_save_ptr_helper(o_string *o, int n)
{
	char **list = (char**)o->data;
	int string_start;
	int string_len;

	if (!o->has_empty_slot) {
		string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
		string_len = o->length - string_start;
		if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
			debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
			/* list[n] points to string_start, make space for 16 more pointers */
			o->maxlen += 0x10 * sizeof(list[0]);
			o->data = xrealloc(o->data, o->maxlen + 1);
			list = (char**)o->data;
			memmove(list + n + 0x10, list + n, string_len);
			o->length += 0x10 * sizeof(list[0]);
		} else
			debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
	} else {
		/* We have empty slot at list[n], reuse without growth */
		string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
		string_len = o->length - string_start;
		debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
		o->has_empty_slot = 0;
	}
	list[n] = (char*)(ptrdiff_t)string_len;
	return n + 1;
}

/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
static int o_get_last_ptr(o_string *o, int n)
{
	char **list = (char**)o->data;
	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);

	return ((int)(ptrdiff_t)list[n-1]) + string_start;
}

/* o_glob performs globbing on last list[], saving each result
 * as a new list[]. */
static int o_glob(o_string *o, int n)
{
	glob_t globdata;
	int gr;
	char *pattern;

	debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
	if (!o->data)
		return o_save_ptr_helper(o, n);
	pattern = o->data + o_get_last_ptr(o, n);
	debug_printf_glob("glob pattern '%s'\n", pattern);
	if (!glob_needed(pattern)) {
 literal:
		o->length = unbackslash(pattern) - o->data;
		debug_printf_glob("glob pattern '%s' is literal\n", pattern);
		return o_save_ptr_helper(o, n);
	}

	memset(&globdata, 0, sizeof(globdata));
	gr = glob(pattern, 0, NULL, &globdata);
	debug_printf_glob("glob('%s'):%d\n", pattern, gr);
	if (gr == GLOB_NOSPACE)
		bb_error_msg_and_die("out of memory during glob");
	if (gr == GLOB_NOMATCH) {
		globfree(&globdata);
		goto literal;
	}
	if (gr != 0) { /* GLOB_ABORTED ? */
//TODO: testcase for bad glob pattern behavior
		bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
	}
	if (globdata.gl_pathv && globdata.gl_pathv[0]) {
		char **argv = globdata.gl_pathv;
		o->length = pattern - o->data; /* "forget" pattern */
		while (1) {
			o_addstr(o, *argv, strlen(*argv) + 1);
			n = o_save_ptr_helper(o, n);
			argv++;
			if (!*argv)
				break;
		}
	}
	globfree(&globdata);
	if (DEBUG_GLOB)
		debug_print_list("o_glob returning", o, n);
	return n;
}

/* If o->o_glob == 1, glob the string so far remembered.
 * Otherwise, just finish current list[] and start new */
static int o_save_ptr(o_string *o, int n)
{
	if (o->o_glob)
		return o_glob(o, n); /* o_save_ptr_helper is inside */
	return o_save_ptr_helper(o, n);
}

/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
static char **o_finalize_list(o_string *o, int n)
{
	char **list;
	int string_start;

	n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
	if (DEBUG_EXPAND)
		debug_print_list("finalized", o, n);
	debug_printf_expand("finalized n:%d\n", n);
	list = (char**)o->data;
	string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
	list[--n] = NULL;
	while (n) {
		n--;
		list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
	}
	return list;
}


/*
 * in_str support
 */
static int static_get(struct in_str *i)
{
	int ch = *i->p++;
	if (ch == '\0') return EOF;
	return ch;
}

static int static_peek(struct in_str *i)
{
	return *i->p;
}

#if ENABLE_HUSH_INTERACTIVE

#if ENABLE_FEATURE_EDITING
static void cmdedit_set_initial_prompt(void)
{
#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
	PS1 = NULL;
#else
	PS1 = getenv("PS1");
	if (PS1 == NULL)
		PS1 = "\\w \\$ ";
#endif
}
#endif /* EDITING */

static const char* setup_prompt_string(int promptmode)
{
	const char *prompt_str;
	debug_printf("setup_prompt_string %d ", promptmode);
#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
	/* Set up the prompt */
	if (promptmode == 0) { /* PS1 */
		free((char*)PS1);
		PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#');
		prompt_str = PS1;
	} else {
		prompt_str = PS2;
	}
#else
	prompt_str = (promptmode == 0) ? PS1 : PS2;
#endif
	debug_printf("result '%s'\n", prompt_str);
	return prompt_str;
}

static void get_user_input(struct in_str *i)
{
	int r;
	const char *prompt_str;

	prompt_str = setup_prompt_string(i->promptmode);
#if ENABLE_FEATURE_EDITING
	/* Enable command line editing only while a command line
	 * is actually being read */
	do {
		r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
	} while (r == 0); /* repeat if Ctrl-C */
	i->eof_flag = (r < 0);
	if (i->eof_flag) { /* EOF/error detected */
		user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
		user_input_buf[1] = '\0';
	}
#else
	fputs(prompt_str, stdout);
	fflush(stdout);
	user_input_buf[0] = r = fgetc(i->file);
	/*user_input_buf[1] = '\0'; - already is and never changed */
	i->eof_flag = (r == EOF);
#endif
	i->p = user_input_buf;
}

#endif  /* INTERACTIVE */

/* This is the magic location that prints prompts
 * and gets data back from the user */
static int file_get(struct in_str *i)
{
	int ch;

	/* If there is data waiting, eat it up */
	if (i->p && *i->p) {
#if ENABLE_HUSH_INTERACTIVE
 take_cached:
#endif
		ch = *i->p++;
		if (i->eof_flag && !*i->p)
			ch = EOF;
	} else {
		/* need to double check i->file because we might be doing something
		 * more complicated by now, like sourcing or substituting. */
#if ENABLE_HUSH_INTERACTIVE
		if (interactive_fd && i->promptme && i->file == stdin) {
			do {
				get_user_input(i);
			} while (!*i->p); /* need non-empty line */
			i->promptmode = 1; /* PS2 */
			i->promptme = 0;
			goto take_cached;
		}
#endif
		ch = fgetc(i->file);
	}
	debug_printf("file_get: got a '%c' %d\n", ch, ch);
#if ENABLE_HUSH_INTERACTIVE
	if (ch == '\n')
		i->promptme = 1;
#endif
	return ch;
}

/* All the callers guarantee this routine will never be
 * used right after a newline, so prompting is not needed.
 */
static int file_peek(struct in_str *i)
{
	int ch;
	if (i->p && *i->p) {
		if (i->eof_flag && !i->p[1])
			return EOF;
		return *i->p;
	}
	ch = fgetc(i->file);
	i->eof_flag = (ch == EOF);
	i->peek_buf[0] = ch;
	i->peek_buf[1] = '\0';
	i->p = i->peek_buf;
	debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
	return ch;
}

static void setup_file_in_str(struct in_str *i, FILE *f)
{
	i->peek = file_peek;
	i->get = file_get;
#if ENABLE_HUSH_INTERACTIVE
	i->promptme = 1;
	i->promptmode = 0; /* PS1 */
#endif
	i->file = f;
	i->p = NULL;
}

static void setup_string_in_str(struct in_str *i, const char *s)
{
	i->peek = static_peek;
	i->get = static_get;
#if ENABLE_HUSH_INTERACTIVE
	i->promptme = 1;
	i->promptmode = 0; /* PS1 */
#endif
	i->p = s;
	i->eof_flag = 0;
}


/* squirrel != NULL means we squirrel away copies of stdin, stdout,
 * and stderr if they are redirected. */
static int setup_redirects(struct child_prog *prog, int squirrel[])
{
	int openfd, mode;
	struct redir_struct *redir;

	for (redir = prog->redirects; redir; redir = redir->next) {
		if (redir->dup == -1 && redir->rd_filename == NULL) {
			/* something went wrong in the parse.  Pretend it didn't happen */
			continue;
		}
		if (redir->dup == -1) {
			char *p;
			mode = redir_table[redir->rd_type].mode;
//TODO: check redir for names like '\\'
			p = expand_string_to_string(redir->rd_filename);
			openfd = open_or_warn(p, mode);
			free(p);
			if (openfd < 0) {
			/* this could get lost if stderr has been redirected, but
			   bash and ash both lose it as well (though zsh doesn't!) */
				return 1;
			}
		} else {
			openfd = redir->dup;
		}

		if (openfd != redir->fd) {
			if (squirrel && redir->fd < 3) {
				squirrel[redir->fd] = dup(redir->fd);
			}
			if (openfd == -3) {
				//close(openfd); // close(-3) ??!
			} else {
				dup2(openfd, redir->fd);
				if (redir->dup == -1)
					close(openfd);
			}
		}
	}
	return 0;
}

static void restore_redirects(int squirrel[])
{
	int i, fd;
	for (i = 0; i < 3; i++) {
		fd = squirrel[i];
		if (fd != -1) {
			/* We simply die on error */
			xmove_fd(fd, i);
		}
	}
}


/* Called after [v]fork() in run_pipe(), or from builtin_exec().
 * Never returns.
 * XXX no exit() here.  If you don't exec, use _exit instead.
 * The at_exit handlers apparently confuse the calling process,
 * in particular stdin handling.  Not sure why? -- because of vfork! (vda) */
static void pseudo_exec_argv(char **ptrs2free, char **argv)
{
	int i, rcode;
	char *p;
	const struct built_in_command *x;

	for (i = 0; is_assignment(argv[i]); i++) {
		debug_printf_exec("pid %d environment modification: %s\n",
				getpid(), argv[i]);
		p = expand_string_to_string(argv[i]);
#if !BB_MMU
		*ptrs2free++ = p;
#endif
		putenv(p);
	}
	argv += i;
	/* If a variable is assigned in a forest, and nobody listens,
	 * was it ever really set?
	 */
	if (!argv[0])
		_exit(EXIT_SUCCESS);

	argv = expand_strvec_to_strvec(argv);
#if !BB_MMU
	*ptrs2free++ = (char*) argv;
#endif

	/*
	 * Check if the command matches any of the builtins.
	 * Depending on context, this might be redundant.  But it's
	 * easier to waste a few CPU cycles than it is to figure out
	 * if this is one of those cases.
	 */
	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
		if (strcmp(argv[0], x->cmd) == 0) {
			debug_printf_exec("running builtin '%s'\n", argv[0]);
			rcode = x->function(argv);
			fflush(stdout);
			_exit(rcode);
		}
	}

	/* Check if the command matches any busybox applets */
#if ENABLE_FEATURE_SH_STANDALONE
	if (strchr(argv[0], '/') == NULL) {
		int a = find_applet_by_name(argv[0]);
		if (a >= 0) {
			if (APPLET_IS_NOEXEC(a)) {
				debug_printf_exec("running applet '%s'\n", argv[0]);
// is it ok that run_applet_no_and_exit() does exit(), not _exit()?
				run_applet_no_and_exit(a, argv);
			}
			/* re-exec ourselves with the new arguments */
			debug_printf_exec("re-execing applet '%s'\n", argv[0]);
			execvp(bb_busybox_exec_path, argv);
			/* If they called chroot or otherwise made the binary no longer
			 * executable, fall through */
		}
	}
#endif

	debug_printf_exec("execing '%s'\n", argv[0]);
	execvp(argv[0], argv);
	bb_perror_msg("cannot exec '%s'", argv[0]);
	_exit(EXIT_FAILURE);
}

/* Called after [v]fork() in run_pipe()
 */
static void pseudo_exec(char **ptrs2free, struct child_prog *child)
{
	if (child->argv)
		pseudo_exec_argv(ptrs2free, child->argv);

	if (child->group) {
#if !BB_MMU
		bb_error_msg_and_die("nested lists are not supported on NOMMU");
#else
		int rcode;
		debug_printf_exec("pseudo_exec: run_list\n");
		rcode = run_list(child->group);
		/* OK to leak memory by not calling free_pipe_list,
		 * since this process is about to exit */
		_exit(rcode);
#endif
	}

	/* Can happen.  See what bash does with ">foo" by itself. */
	debug_printf("trying to pseudo_exec null command\n");
	_exit(EXIT_SUCCESS);
}

#if ENABLE_HUSH_JOB
static const char *get_cmdtext(struct pipe *pi)
{
	char **argv;
	char *p;
	int len;

	/* This is subtle. ->cmdtext is created only on first backgrounding.
	 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
	 * On subsequent bg argv is trashed, but we won't use it */
	if (pi->cmdtext)
		return pi->cmdtext;
	argv = pi->progs[0].argv;
	if (!argv || !argv[0]) {
		pi->cmdtext = xzalloc(1);
		return pi->cmdtext;
	}

	len = 0;
	do len += strlen(*argv) + 1; while (*++argv);
	pi->cmdtext = p = xmalloc(len);
	argv = pi->progs[0].argv;
	do {
		len = strlen(*argv);
		memcpy(p, *argv, len);
		p += len;
		*p++ = ' ';
	} while (*++argv);
	p[-1] = '\0';
	return pi->cmdtext;
}

static void insert_bg_job(struct pipe *pi)
{
	struct pipe *thejob;
	int i;

	/* Linear search for the ID of the job to use */
	pi->jobid = 1;
	for (thejob = job_list; thejob; thejob = thejob->next)
		if (thejob->jobid >= pi->jobid)
			pi->jobid = thejob->jobid + 1;

	/* Add thejob to the list of running jobs */
	if (!job_list) {
		thejob = job_list = xmalloc(sizeof(*thejob));
	} else {
		for (thejob = job_list; thejob->next; thejob = thejob->next)
			continue;
		thejob->next = xmalloc(sizeof(*thejob));
		thejob = thejob->next;
	}

	/* Physically copy the struct job */
	memcpy(thejob, pi, sizeof(struct pipe));
	thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs);
	/* We cannot copy entire pi->progs[] vector! Double free()s will happen */
	for (i = 0; i < pi->num_progs; i++) {
// TODO: do we really need to have so many fields which are just dead weight
// at execution stage?
		thejob->progs[i].pid = pi->progs[i].pid;
		/* all other fields are not used and stay zero */
	}
	thejob->next = NULL;
	thejob->cmdtext = xstrdup(get_cmdtext(pi));

	/* We don't wait for background thejobs to return -- append it
	   to the list of backgrounded thejobs and leave it alone */
	printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
	last_bg_pid = thejob->progs[0].pid;
	last_jobid = thejob->jobid;
}

static void remove_bg_job(struct pipe *pi)
{
	struct pipe *prev_pipe;

	if (pi == job_list) {
		job_list = pi->next;
	} else {
		prev_pipe = job_list;
		while (prev_pipe->next != pi)
			prev_pipe = prev_pipe->next;
		prev_pipe->next = pi->next;
	}
	if (job_list)
		last_jobid = job_list->jobid;
	else
		last_jobid = 0;
}

/* Remove a backgrounded job */
static void delete_finished_bg_job(struct pipe *pi)
{
	remove_bg_job(pi);
	pi->stopped_progs = 0;
	free_pipe(pi, 0);
	free(pi);
}
#endif /* JOB */

/* Check to see if any processes have exited -- if they
 * have, figure out why and see if a job has completed */
static int checkjobs(struct pipe* fg_pipe)
{
	int attributes;
	int status;
#if ENABLE_HUSH_JOB
	struct pipe *pi;
#endif
	pid_t childpid;
	int rcode = 0;

	attributes = WUNTRACED;
	if (fg_pipe == NULL)
		attributes |= WNOHANG;

/* Do we do this right?
 * bash-3.00# sleep 20 | false
 * <ctrl-Z pressed>
 * [3]+  Stopped          sleep 20 | false
 * bash-3.00# echo $?
 * 1   <========== bg pipe is not fully done, but exitcode is already known!
 */

//FIXME: non-interactive bash does not continue even if all processes in fg pipe
//are stopped. Testcase: "cat | cat" in a script (not on command line)
// + killall -STOP cat

 wait_more:
// TODO: safe_waitpid?
	while ((childpid = waitpid(-1, &status, attributes)) > 0) {
		int i;
		const int dead = WIFEXITED(status) || WIFSIGNALED(status);
#if DEBUG_JOBS
		if (WIFSTOPPED(status))
			debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
					childpid, WSTOPSIG(status), WEXITSTATUS(status));
		if (WIFSIGNALED(status))
			debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
					childpid, WTERMSIG(status), WEXITSTATUS(status));
		if (WIFEXITED(status))
			debug_printf_jobs("pid %d exited, exitcode %d\n",
					childpid, WEXITSTATUS(status));
#endif
		/* Were we asked to wait for fg pipe? */
		if (fg_pipe) {
			for (i = 0; i < fg_pipe->num_progs; i++) {
				debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
				if (fg_pipe->progs[i].pid != childpid)
					continue;
				/* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
				if (dead) {
					fg_pipe->progs[i].pid = 0;
					fg_pipe->alive_progs--;
					if (i == fg_pipe->num_progs - 1) {
						/* last process gives overall exitstatus */
						rcode = WEXITSTATUS(status);
						IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
					}
				} else {
					fg_pipe->progs[i].is_stopped = 1;
					fg_pipe->stopped_progs++;
				}
				debug_printf_jobs("fg_pipe: alive_progs %d stopped_progs %d\n",
						fg_pipe->alive_progs, fg_pipe->stopped_progs);
				if (fg_pipe->alive_progs - fg_pipe->stopped_progs <= 0) {
					/* All processes in fg pipe have exited/stopped */
#if ENABLE_HUSH_JOB
					if (fg_pipe->alive_progs)
						insert_bg_job(fg_pipe);
#endif
					return rcode;
				}
				/* There are still running processes in the fg pipe */
				goto wait_more; /* do waitpid again */
			}
			/* it wasnt fg_pipe, look for process in bg pipes */
		}

#if ENABLE_HUSH_JOB
		/* We asked to wait for bg or orphaned children */
		/* No need to remember exitcode in this case */
		for (pi = job_list; pi; pi = pi->next) {
			for (i = 0; i < pi->num_progs; i++) {
				if (pi->progs[i].pid == childpid)
					goto found_pi_and_prognum;
			}
		}
		/* Happens when shell is used as init process (init=/bin/sh) */
		debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
		continue; /* do waitpid again */

 found_pi_and_prognum:
		if (dead) {
			/* child exited */
			pi->progs[i].pid = 0;
			pi->alive_progs--;
			if (!pi->alive_progs) {
				printf(JOB_STATUS_FORMAT, pi->jobid,
						"Done", pi->cmdtext);
				delete_finished_bg_job(pi);
			}
		} else {
			/* child stopped */
			pi->progs[i].is_stopped = 1;
			pi->stopped_progs++;
		}
#endif
	} /* while (waitpid succeeds)... */

	/* wait found no children or failed */

	if (childpid && errno != ECHILD)
		bb_perror_msg("waitpid");
	return rcode;
}

#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
{
	pid_t p;
	int rcode = checkjobs(fg_pipe);
	/* Job finished, move the shell to the foreground */
	p = getpgid(0); /* pgid of our process */
	debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
	tcsetpgrp(interactive_fd, p);
//	if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
//		bb_perror_msg("tcsetpgrp-4a");
	return rcode;
}
#endif

/* run_pipe() starts all the jobs, but doesn't wait for anything
 * to finish.  See checkjobs().
 *
 * return code is normally -1, when the caller has to wait for children
 * to finish to determine the exit status of the pipe.  If the pipe
 * is a simple builtin command, however, the action is done by the
 * time run_pipe returns, and the exit code is provided as the
 * return value.
 *
 * The input of the pipe is always stdin, the output is always
 * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
 * because it tries to avoid running the command substitution in
 * subshell, when that is in fact necessary.  The subshell process
 * now has its stdout directed to the input of the appropriate pipe,
 * so this routine is noticeably simpler.
 *
 * Returns -1 only if started some children. IOW: we have to
 * mask out retvals of builtins etc with 0xff!
 */
static int run_pipe(struct pipe *pi)
{
	int i;
	int nextin;
	int pipefds[2];		/* pipefds[0] is for reading */
	struct child_prog *child;
	const struct built_in_command *x;
	char *p;
	/* it is not always needed, but we aim to smaller code */
	int squirrel[] = { -1, -1, -1 };
	int rcode;
	const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);

	debug_printf_exec("run_pipe start: single_fg=%d\n", single_fg);

#if ENABLE_HUSH_JOB
	pi->pgrp = -1;
#endif
	pi->alive_progs = 1;
	pi->stopped_progs = 0;

	/* Check if this is a simple builtin (not part of a pipe).
	 * Builtins within pipes have to fork anyway, and are handled in
	 * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
	 */
	child = &(pi->progs[0]);
	if (single_fg && child->group && child->subshell == 0) {
		debug_printf("non-subshell grouping\n");
		setup_redirects(child, squirrel);
		debug_printf_exec(": run_list\n");
		rcode = run_list(child->group) & 0xff;
		restore_redirects(squirrel);
		debug_printf_exec("run_pipe return %d\n", rcode);
		IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
		return rcode;
	}

	if (single_fg && child->argv != NULL) {
		char **argv_expanded;
		char **argv = child->argv;

		for (i = 0; is_assignment(argv[i]); i++)
			continue;
		if (i != 0 && argv[i] == NULL) {
			/* assignments, but no command: set the local environment */
			for (i = 0; argv[i] != NULL; i++) {
				debug_printf("local environment set: %s\n", argv[i]);
				p = expand_string_to_string(argv[i]);
				set_local_var(p, 0);
			}
			return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
		}
		for (i = 0; is_assignment(argv[i]); i++) {
			p = expand_string_to_string(argv[i]);
			putenv(p);
//FIXME: do we leak p?!
		}
		for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
			if (strcmp(argv[i], x->cmd) == 0) {
				if (x->function == builtin_exec && argv[i+1] == NULL) {
					debug_printf("magic exec\n");
					setup_redirects(child, NULL);
					return EXIT_SUCCESS;
				}
				debug_printf("builtin inline %s\n", argv[0]);
				/* XXX setup_redirects acts on file descriptors, not FILEs.
				 * This is perfect for work that comes after exec().
				 * Is it really safe for inline use?  Experimentally,
				 * things seem to work with glibc. */
				setup_redirects(child, squirrel);
				debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
				argv_expanded = expand_strvec_to_strvec(argv + i);
				rcode = x->function(argv_expanded) & 0xff;
				free(argv_expanded);
				restore_redirects(squirrel);
				debug_printf_exec("run_pipe return %d\n", rcode);
				IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
				return rcode;
			}
		}
#if ENABLE_FEATURE_SH_STANDALONE
		{
			int a = find_applet_by_name(argv[i]);
			if (a >= 0 && APPLET_IS_NOFORK(a)) {
				setup_redirects(child, squirrel);
				save_nofork_data(&nofork_save);
				argv_expanded = argv + i;
				argv_expanded = expand_strvec_to_strvec(argv + i);
				debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
				rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded);
				free(argv_expanded);
				restore_redirects(squirrel);
				debug_printf_exec("run_pipe return %d\n", rcode);
				IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
				return rcode;
			}
		}
#endif
	}

	/* Disable job control signals for shell (parent) and
	 * for initial child code after fork */
	set_jobctrl_sighandler(SIG_IGN);

	/* Going to fork a child per each pipe member */
	pi->alive_progs = 0;
	nextin = 0;

	for (i = 0; i < pi->num_progs; i++) {
#if !BB_MMU
		char **ptrs2free = NULL;
#endif
		child = &(pi->progs[i]);
		if (child->argv) {
			debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
#if !BB_MMU
			ptrs2free = alloc_ptrs(child->argv);
#endif
		} else
			debug_printf_exec(": pipe member with no argv\n");

		/* pipes are inserted between pairs of commands */
		pipefds[0] = 0;
		pipefds[1] = 1;
		if ((i + 1) < pi->num_progs)
			xpipe(pipefds);

		child->pid = BB_MMU ? fork() : vfork();
		if (!child->pid) { /* child */
			if (ENABLE_HUSH_JOB)
				die_sleep = 0; /* let nofork's xfuncs die */
#if ENABLE_HUSH_JOB
			/* Every child adds itself to new process group
			 * with pgid == pid_of_first_child_in_pipe */
			if (run_list_level == 1 && interactive_fd) {
				pid_t pgrp;
				/* Don't do pgrp restore anymore on fatal signals */
				set_fatal_sighandler(SIG_DFL);
				pgrp = pi->pgrp;
				if (pgrp < 0) /* true for 1st process only */
					pgrp = getpid();
				if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
					/* We do it in *every* child, not just first,
					 * to avoid races */
					tcsetpgrp(interactive_fd, pgrp);
				}
			}
#endif
			xmove_fd(nextin, 0);
			xmove_fd(pipefds[1], 1); /* write end */
			if (pipefds[0] > 1)
				close(pipefds[0]); /* read end */
			/* Like bash, explicit redirects override pipes,
			 * and the pipe fd is available for dup'ing. */
			setup_redirects(child, NULL);

			/* Restore default handlers just prior to exec */
			set_jobctrl_sighandler(SIG_DFL);
			set_misc_sighandler(SIG_DFL);
			signal(SIGCHLD, SIG_DFL);
			pseudo_exec(ptrs2free, child); /* does not return */
		}
#if !BB_MMU
		free_strings(ptrs2free);
#endif
		if (child->pid < 0) { /* [v]fork failed */
			/* Clearly indicate, was it fork or vfork */
			bb_perror_msg(BB_MMU ? "fork" : "vfork");
		} else {
			pi->alive_progs++;
#if ENABLE_HUSH_JOB
			/* Second and next children need to know pid of first one */
			if (pi->pgrp < 0)
				pi->pgrp = child->pid;
#endif
		}

		if (i)
			close(nextin);
		if ((i + 1) < pi->num_progs)
			close(pipefds[1]); /* write end */
		/* Pass read (output) pipe end to next iteration */
		nextin = pipefds[0];
	}

	if (!pi->alive_progs) {
		debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
		return 1;
	}

	debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_progs);
	return -1;
}

#ifndef debug_print_tree
static void debug_print_tree(struct pipe *pi, int lvl)
{
	static const char *PIPE[] = {
		[PIPE_SEQ] = "SEQ",
		[PIPE_AND] = "AND",
		[PIPE_OR ] = "OR" ,
		[PIPE_BG ] = "BG" ,
	};
	static const char *RES[] = {
		[RES_NONE ] = "NONE" ,
#if ENABLE_HUSH_IF
		[RES_IF   ] = "IF"   ,
		[RES_THEN ] = "THEN" ,
		[RES_ELIF ] = "ELIF" ,
		[RES_ELSE ] = "ELSE" ,
		[RES_FI   ] = "FI"   ,
#endif
#if ENABLE_HUSH_LOOPS
		[RES_FOR  ] = "FOR"  ,
		[RES_WHILE] = "WHILE",
		[RES_UNTIL] = "UNTIL",
		[RES_DO   ] = "DO"   ,
		[RES_DONE ] = "DONE" ,
		[RES_IN   ] = "IN"   ,
#endif
#if ENABLE_HUSH_CASE
		[RES_CASE ] = "CASE" ,
		[RES_MATCH] = "MATCH",
		[RES_CASEI] = "CASEI",
		[RES_ESAC ] = "ESAC" ,
#endif
		[RES_XXXX ] = "XXXX" ,
		[RES_SNTX ] = "SNTX" ,
	};

	int pin, prn;

	pin = 0;
	while (pi) {
		fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
				pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
		prn = 0;
		while (prn < pi->num_progs) {
			struct child_prog *child = &pi->progs[prn];
			char **argv = child->argv;

			fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
			if (child->group) {
				fprintf(stderr, " group %s: (argv=%p)\n",
						(child->subshell ? "()" : "{}"),
						argv);
				debug_print_tree(child->group, lvl+1);
				prn++;
				continue;
			}
			if (argv) while (*argv) {
				fprintf(stderr, " '%s'", *argv);
				argv++;
			}
			fprintf(stderr, "\n");
			prn++;
		}
		pi = pi->next;
		pin++;
	}
}
#endif

/* NB: called by pseudo_exec, and therefore must not modify any
 * global data until exec/_exit (we can be a child after vfork!) */
static int run_list(struct pipe *pi)
{
	struct pipe *rpipe;
#if ENABLE_HUSH_LOOPS
	char *for_varname = NULL;
	char **for_lcur = NULL;
	char **for_list = NULL;
	int flag_rep = 0;
#endif
#if ENABLE_HUSH_CASE
	char *case_word = NULL;
#endif
	int flag_skip = 1;
	int rcode = 0; /* probably for gcc only */
	int flag_restore = 0;
#if ENABLE_HUSH_IF
	int if_code = 0, next_if_code = 0;  /* need double-buffer to handle elif */
#else
	enum { if_code = 0, next_if_code = 0 };
#endif
	reserved_style rword IF_HAS_NO_KEYWORDS(= RES_NONE);
	reserved_style skip_more_for_this_rword = RES_XXXX;

	debug_printf_exec("run_list start lvl %d\n", run_list_level + 1);

#if ENABLE_HUSH_LOOPS
	/* check syntax for "for" */
	for (rpipe = pi; rpipe; rpipe = rpipe->next) {
		if (rpipe->res_word != RES_FOR && rpipe->res_word != RES_IN)
			continue;
		/* current word is FOR or IN (BOLD in comments below) */
		if (rpipe->next == NULL) {
			syntax("malformed for");
			debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
			return 1;
		}
		/* "FOR v; do ..." and "for v IN a b; do..." are ok */
		if (rpipe->next->res_word == RES_DO)
			continue;
		/* next word is not "do". It must be "in" then ("FOR v in ...") */
		if (rpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
		 || rpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
		) {
			syntax("malformed for");
			debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
			return 1;
		}
	}
#else
	rpipe = NULL;
#endif

#if ENABLE_HUSH_JOB
	/* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
	 * We are saving state before entering outermost list ("while...done")
	 * so that ctrl-Z will correctly background _entire_ outermost list,
	 * not just a part of it (like "sleep 1 | exit 2") */
	if (++run_list_level == 1 && interactive_fd) {
		if (sigsetjmp(toplevel_jb, 1)) {
			/* ctrl-Z forked and we are parent; or ctrl-C.
			 * Sighandler has longjmped us here */
			signal(SIGINT, SIG_IGN);
			signal(SIGTSTP, SIG_IGN);
			/* Restore level (we can be coming from deep inside
			 * nested levels) */
			run_list_level = 1;
#if ENABLE_FEATURE_SH_STANDALONE
			if (nofork_save.saved) { /* if save area is valid */
				debug_printf_jobs("exiting nofork early\n");
				restore_nofork_data(&nofork_save);
			}
#endif
			if (ctrl_z_flag) {
				/* ctrl-Z has forked and stored pid of the child in pi->pid.
				 * Remember this child as background job */
				insert_bg_job(pi);
			} else {
				/* ctrl-C. We just stop doing whatever we were doing */
				bb_putchar('\n');
			}
			rcode = 0;
			goto ret;
		}
		/* ctrl-Z handler will store pid etc in pi */
		toplevel_list = pi;
		ctrl_z_flag = 0;
#if ENABLE_FEATURE_SH_STANDALONE
		nofork_save.saved = 0; /* in case we will run a nofork later */
#endif
		signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
		signal(SIGINT, handler_ctrl_c);
	}
#endif /* JOB */

	for (; pi; pi = flag_restore ? rpipe : pi->next) {
		IF_HAS_KEYWORDS(rword = pi->res_word;)
		IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
#if ENABLE_HUSH_LOOPS
		if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
			flag_restore = 0;
			if (!rpipe) {
				flag_rep = 0;
				rpipe = pi;
			}
		}
#endif
		debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n",
				rword, if_code, next_if_code, skip_more_for_this_rword);
		if (rword == skip_more_for_this_rword && flag_skip) {
			if (pi->followup == PIPE_SEQ)
				flag_skip = 0;
			continue;
		}
		flag_skip = 1;
		skip_more_for_this_rword = RES_XXXX;
#if ENABLE_HUSH_IF
		if (rword == RES_THEN || rword == RES_ELSE)
			if_code = next_if_code;
		if (rword == RES_THEN && if_code)
			continue;
		if (rword == RES_ELSE && !if_code)
			continue;
		if (rword == RES_ELIF && !if_code)
			break;
#endif
#if ENABLE_HUSH_LOOPS
		if (rword == RES_FOR && pi->num_progs) {
			if (!for_lcur) {
				/* first loop through for */

				static const char encoded_dollar_at[] ALIGN1 = {
					SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
				}; /* encoded representation of "$@" */
				static const char *const encoded_dollar_at_argv[] = {
					encoded_dollar_at, NULL
				}; /* argv list with one element: "$@" */
				char **vals;

				vals = (char**)encoded_dollar_at_argv;
				if (rpipe->next->res_word == RES_IN) {
					/* if no variable values after "in" we skip "for" */
					if (!pi->next->progs->argv)
						continue;
					vals = pi->next->progs->argv;
				} /* else: "for var; do..." -> assume "$@" list */
				/* create list of variable values */
				debug_print_strings("for_list made from", vals);
				for_list = expand_strvec_to_strvec(vals);
				for_lcur = for_list;
				debug_print_strings("for_list", for_list);
				for_varname = pi->progs->argv[0];
				pi->progs->argv[0] = NULL;
				flag_rep = 1;
			}
			free(pi->progs->argv[0]);
			if (!*for_lcur) {
				/* for loop is over, clean up */
				free(for_list);
				for_lcur = NULL;
				flag_rep = 0;
				pi->progs->argv[0] = for_varname;
				continue;
			}
			/* insert next value from for_lcur */
			/* vda: does it need escaping? */
			pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
		}
		if (rword == RES_IN)
			continue;
		if (rword == RES_DO) {
			if (!flag_rep)
				continue;
		}
		if (rword == RES_DONE) {
			if (flag_rep) {
				flag_restore = 1;
			} else {
				rpipe = NULL;
			}
		}
#endif
#if ENABLE_HUSH_CASE
		if (rword == RES_CASE) {
			case_word = pi->progs->argv[0];
			continue;
		}
		if (rword == RES_MATCH) {
			if (case_word) {
				next_if_code = strcmp(case_word, pi->progs->argv[0]);
				if (next_if_code == 0)
					case_word = NULL;
				continue;
			}
			break;
		}
		if (rword == RES_CASEI) {
			if (next_if_code != 0)
				continue;
		}
#endif

		if (pi->num_progs == 0)
			continue;
		debug_printf_exec(": run_pipe with %d members\n", pi->num_progs);
		rcode = run_pipe(pi);
		if (rcode != -1) {
			/* We only ran a builtin: rcode was set by the return value
			 * of run_pipe(), and we don't need to wait for anything. */
		} else if (pi->followup == PIPE_BG) {
			/* What does bash do with attempts to background builtins? */
			/* Even bash 3.2 doesn't do that well with nested bg:
			 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
			 * I'm NOT treating inner &'s as jobs */
#if ENABLE_HUSH_JOB
			if (run_list_level == 1)
				insert_bg_job(pi);
#endif
			rcode = EXIT_SUCCESS;
		} else {
#if ENABLE_HUSH_JOB
			if (run_list_level == 1 && interactive_fd) {
				/* waits for completion, then fg's main shell */
				rcode = checkjobs_and_fg_shell(pi);
			} else
#endif
			{ /* this one just waits for completion */
				rcode = checkjobs(pi);
			}
			debug_printf_exec(": checkjobs returned %d\n", rcode);
		}
		debug_printf_exec(": setting last_return_code=%d\n", rcode);
		last_return_code = rcode;
#if ENABLE_HUSH_IF
		if (rword == RES_IF || rword == RES_ELIF)
			next_if_code = rcode;  /* can be overwritten a number of times */
#endif
#if ENABLE_HUSH_LOOPS
		if (rword == RES_WHILE)
			flag_rep = !last_return_code;
		if (rword == RES_UNTIL)
			flag_rep = last_return_code;
#endif
		if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
		 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
		) {
			skip_more_for_this_rword = rword;
		}
		checkjobs(NULL);
	} /* for (pi) */

#if ENABLE_HUSH_JOB
	if (ctrl_z_flag) {
		/* ctrl-Z forked somewhere in the past, we are the child,
		 * and now we completed running the list. Exit. */
//TODO: _exit?
		exit(rcode);
	}
 ret:
	if (!--run_list_level && interactive_fd) {
		signal(SIGTSTP, SIG_IGN);
		signal(SIGINT, SIG_IGN);
	}
#endif
	debug_printf_exec("run_list lvl %d return %d\n", run_list_level + 1, rcode);
	return rcode;
}

/* return code is the exit status of the pipe */
static int free_pipe(struct pipe *pi, int indent)
{
	char **p;
	struct child_prog *child;
	struct redir_struct *r, *rnext;
	int a, i, ret_code = 0;

	if (pi->stopped_progs > 0)
		return ret_code;
	debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
	for (i = 0; i < pi->num_progs; i++) {
		child = &pi->progs[i];
		debug_printf_clean("%s  command %d:\n", indenter(indent), i);
		if (child->argv) {
			for (a = 0, p = child->argv; *p; a++, p++) {
				debug_printf_clean("%s   argv[%d] = %s\n", indenter(indent), a, *p);
			}
			free_strings(child->argv);
			child->argv = NULL;
		} else if (child->group) {
			debug_printf_clean("%s   begin group (subshell:%d)\n", indenter(indent), child->subshell);
			ret_code = free_pipe_list(child->group, indent+3);
			debug_printf_clean("%s   end group\n", indenter(indent));
		} else {
			debug_printf_clean("%s   (nil)\n", indenter(indent));
		}
		for (r = child->redirects; r; r = rnext) {
			debug_printf_clean("%s   redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
			if (r->dup == -1) {
				/* guard against the case >$FOO, where foo is unset or blank */
				if (r->rd_filename) {
					debug_printf_clean(" %s\n", r->rd_filename);
					free(r->rd_filename);
					r->rd_filename = NULL;
				}
			} else {
				debug_printf_clean("&%d\n", r->dup);
			}
			rnext = r->next;
			free(r);
		}
		child->redirects = NULL;
	}
	free(pi->progs);   /* children are an array, they get freed all at once */
	pi->progs = NULL;
#if ENABLE_HUSH_JOB
	free(pi->cmdtext);
	pi->cmdtext = NULL;
#endif
	return ret_code;
}

static int free_pipe_list(struct pipe *head, int indent)
{
	int rcode = 0;   /* if list has no members */
	struct pipe *pi, *next;

	for (pi = head; pi; pi = next) {
#if HAS_KEYWORDS
		debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
#endif
		rcode = free_pipe(pi, indent);
		debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
		next = pi->next;
		/*pi->next = NULL;*/
		free(pi);
	}
	return rcode;
}

/* Select which version we will use */
static int run_and_free_list(struct pipe *pi)
{
	int rcode = 0;
	debug_printf_exec("run_and_free_list entered\n");
	if (!fake_mode) {
		debug_printf_exec(": run_list with %d members\n", pi->num_progs);
		rcode = run_list(pi);
	}
	/* free_pipe_list has the side effect of clearing memory.
	 * In the long run that function can be merged with run_list,
	 * but doing that now would hobble the debugging effort. */
	free_pipe_list(pi, /* indent: */ 0);
	debug_printf_exec("run_and_free_list return %d\n", rcode);
	return rcode;
}


/* expand_strvec_to_strvec() takes a list of strings, expands
 * all variable references within and returns a pointer to
 * a list of expanded strings, possibly with larger number
 * of strings. (Think VAR="a b"; echo $VAR).
 * This new list is allocated as a single malloc block.
 * NULL-terminated list of char* pointers is at the beginning of it,
 * followed by strings themself.
 * Caller can deallocate entire list by single free(list). */

/* Store given string, finalizing the word and starting new one whenever
 * we encounter ifs char(s). This is used for expanding variable values.
 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
static int expand_on_ifs(o_string *output, int n, const char *str)
{
	while (1) {
		int word_len = strcspn(str, ifs);
		if (word_len) {
			if (output->o_quote || !output->o_glob)
				o_addQstr(output, str, word_len);
			else /* protect backslashes against globbing up :) */
				o_addstr_duplicate_backslash(output, str, word_len);
			str += word_len;
		}
		if (!*str)  /* EOL - do not finalize word */
			break;
		o_addchr(output, '\0');
		debug_print_list("expand_on_ifs", output, n);
		n = o_save_ptr(output, n);
		str += strspn(str, ifs); /* skip ifs chars */
	}
	debug_print_list("expand_on_ifs[1]", output, n);
	return n;
}

/* Expand all variable references in given string, adding words to list[]
 * at n, n+1,... positions. Return updated n (so that list[n] is next one
 * to be filled). This routine is extremely tricky: has to deal with
 * variables/parameters with whitespace, $* and $@, and constructs like
 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
/* NB: another bug is that we cannot detect empty strings yet:
 * "" or $empty"" expands to zero words, has to expand to empty word */
static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
{
	/* or_mask is either 0 (normal case) or 0x80
	 * (expansion of right-hand side of assignment == 1-element expand.
	 * It will also do no globbing, and thus we must not backslash-quote!) */

	char first_ch, ored_ch;
	int i;
	const char *val;
	char *p;

	ored_ch = 0;

	debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
	debug_print_list("expand_vars_to_list", output, n);
	n = o_save_ptr(output, n);
	debug_print_list("expand_vars_to_list[0]", output, n);

	while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
#if ENABLE_HUSH_TICK
		o_string subst_result = NULL_O_STRING;
#endif

		o_addstr(output, arg, p - arg);
		debug_print_list("expand_vars_to_list[1]", output, n);
		arg = ++p;
		p = strchr(p, SPECIAL_VAR_SYMBOL);

		first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
		/* "$@" is special. Even if quoted, it can still
		 * expand to nothing (not even an empty string) */
		if ((first_ch & 0x7f) != '@')
			ored_ch |= first_ch;
		val = NULL;
		switch (first_ch & 0x7f) {
		/* Highest bit in first_ch indicates that var is double-quoted */
		case '$': /* pid */
			val = utoa(root_pid);
			break;
		case '!': /* bg pid */
			val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
			break;
		case '?': /* exitcode */
			val = utoa(last_return_code);
			break;
		case '#': /* argc */
			val = utoa(global_argc ? global_argc-1 : 0);
			break;
		case '*':
		case '@':
			i = 1;
			if (!global_argv[i])
				break;
			ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
			if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
				smallint sv = output->o_quote;
				/* unquoted var's contents should be globbed, so don't quote */
				output->o_quote = 0;
				while (global_argv[i]) {
					n = expand_on_ifs(output, n, global_argv[i]);
					debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
					if (global_argv[i++][0] && global_argv[i]) {
						/* this argv[] is not empty and not last:
						 * put terminating NUL, start new word */
						o_addchr(output, '\0');
						debug_print_list("expand_vars_to_list[2]", output, n);
						n = o_save_ptr(output, n);
						debug_print_list("expand_vars_to_list[3]", output, n);
					}
				}
				output->o_quote = sv;
			} else
			/* If or_mask is nonzero, we handle assignment 'a=....$@.....'
			 * and in this case should treat it like '$*' - see 'else...' below */
			if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
				while (1) {
					o_addQstr(output, global_argv[i], strlen(global_argv[i]));
					if (++i >= global_argc)
						break;
					o_addchr(output, '\0');
					debug_print_list("expand_vars_to_list[4]", output, n);
					n = o_save_ptr(output, n);
				}
			} else { /* quoted $*: add as one word */
				while (1) {
					o_addQstr(output, global_argv[i], strlen(global_argv[i]));
					if (!global_argv[++i])
						break;
					if (ifs[0])
						o_addchr(output, ifs[0]);
				}
			}
			break;
		case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
			/* "Empty variable", used to make "" etc to not disappear */
			arg++;
			ored_ch = 0x80;
			break;
#if ENABLE_HUSH_TICK
		case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
			struct in_str input;
			*p = '\0';
			arg++;
//TODO: can we just stuff it into "output" directly?
			debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
			setup_string_in_str(&input, arg);
			process_command_subs(&subst_result, &input, NULL);
			debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
			val = subst_result.data;
			goto store_val;
		}
#endif
		default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
			*p = '\0';
			arg[0] = first_ch & 0x7f;
			if (isdigit(arg[0])) {
				i = xatoi_u(arg);
				if (i < global_argc)
					val = global_argv[i];
				/* else val remains NULL: $N with too big N */
			} else
				val = lookup_param(arg);
			arg[0] = first_ch;
#if ENABLE_HUSH_TICK
 store_val:
#endif
			*p = SPECIAL_VAR_SYMBOL;
			if (!(first_ch & 0x80)) { /* unquoted $VAR */
				debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
				if (val) {
					/* unquoted var's contents should be globbed, so don't quote */
					smallint sv = output->o_quote;
					output->o_quote = 0;
					n = expand_on_ifs(output, n, val);
					val = NULL;
					output->o_quote = sv;
				}
			} else { /* quoted $VAR, val will be appended below */
				debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
			}
		}
		if (val) {
			o_addQstr(output, val, strlen(val));
		}

#if ENABLE_HUSH_TICK
		o_free(&subst_result);
#endif
		arg = ++p;
	} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */

	if (arg[0]) {
		debug_print_list("expand_vars_to_list[a]", output, n);
		/* this part is literal, and it was already pre-quoted
		 * if needed (much earlier), do not use o_addQstr here! */
		o_addstr(output, arg, strlen(arg) + 1);
		debug_print_list("expand_vars_to_list[b]", output, n);
	} else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
	 && !(ored_ch & 0x80) /* and all vars were not quoted. */
	) {
		n--;
		/* allow to reuse list[n] later without re-growth */
		output->has_empty_slot = 1;
	} else {
		o_addchr(output, '\0');
	}
	return n;
}

static char **expand_variables(char **argv, int or_mask)
{
	int n;
	char **list;
	char **v;
	o_string output = NULL_O_STRING;

	if (or_mask & 0x100) {
		output.o_quote = 1; /* protect against globbing for "$var" */
		/* (unquoted $var will temporarily switch it off) */
		output.o_glob = 1;
	}

	n = 0;
	v = argv;
	while (*v) {
		n = expand_vars_to_list(&output, n, *v, (char)or_mask);
		v++;
	}
	debug_print_list("expand_variables", &output, n);

	/* output.data (malloced in one block) gets returned in "list" */
	list = o_finalize_list(&output, n);
	debug_print_strings("expand_variables[1]", list);
	return list;
}

static char **expand_strvec_to_strvec(char **argv)
{
	return expand_variables(argv, 0x100);
}

/* Used for expansion of right hand of assignments */
/* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
 * "v=/bin/c*" */
static char *expand_string_to_string(const char *str)
{
	char *argv[2], **list;

	argv[0] = (char*)str;
	argv[1] = NULL;
	list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
	if (HUSH_DEBUG)
		if (!list[0] || list[1])
			bb_error_msg_and_die("BUG in varexp2");
	/* actually, just move string 2*sizeof(char*) bytes back */
	strcpy((char*)list, list[0]);
	debug_printf_expand("string_to_string='%s'\n", (char*)list);
	return (char*)list;
}

/* Used for "eval" builtin */
static char* expand_strvec_to_string(char **argv)
{
	char **list;

	list = expand_variables(argv, 0x80);
	/* Convert all NULs to spaces */
	if (list[0]) {
		int n = 1;
		while (list[n]) {
			if (HUSH_DEBUG)
				if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
					bb_error_msg_and_die("BUG in varexp3");
			list[n][-1] = ' '; /* TODO: or to ifs[0]? */
			n++;
		}
	}
	strcpy((char*)list, list[0]);
	debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
	return (char*)list;
}


/* Used to get/check local shell variables */
static struct variable *get_local_var(const char *name)
{
	struct variable *cur;
	int len;

	if (!name)
		return NULL;
	len = strlen(name);
	for (cur = top_var; cur; cur = cur->next) {
		if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
			return cur;
	}
	return NULL;
}

/* str holds "NAME=VAL" and is expected to be malloced.
 * We take ownership of it. */
static int set_local_var(char *str, int flg_export)
{
	struct variable *cur;
	char *value;
	int name_len;

	value = strchr(str, '=');
	if (!value) { /* not expected to ever happen? */
		free(str);
		return -1;
	}

	name_len = value - str + 1; /* including '=' */
	cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
	while (1) {
		if (strncmp(cur->varstr, str, name_len) != 0) {
			if (!cur->next) {
				/* Bail out. Note that now cur points
				 * to last var in linked list */
				break;
			}
			cur = cur->next;
			continue;
		}
		/* We found an existing var with this name */
		*value = '\0';
		if (cur->flg_read_only) {
			bb_error_msg("%s: readonly variable", str);
			free(str);
			return -1;
		}
		unsetenv(str); /* just in case */
		*value = '=';
		if (strcmp(cur->varstr, str) == 0) {
 free_and_exp:
			free(str);
			goto exp;
		}
		if (cur->max_len >= strlen(str)) {
			/* This one is from startup env, reuse space */
			strcpy(cur->varstr, str);
			goto free_and_exp;
		}
		/* max_len == 0 signifies "malloced" var, which we can
		 * (and has to) free */
		if (!cur->max_len)
			free(cur->varstr);
		cur->max_len = 0;
		goto set_str_and_exp;
	}

	/* Not found - create next variable struct */
	cur->next = xzalloc(sizeof(*cur));
	cur = cur->next;

 set_str_and_exp:
	cur->varstr = str;
 exp:
	if (flg_export)
		cur->flg_export = 1;
	if (cur->flg_export)
		return putenv(cur->varstr);
	return 0;
}

static void unset_local_var(const char *name)
{
	struct variable *cur;
	struct variable *prev = prev; /* for gcc */
	int name_len;

	if (!name)
		return;
	name_len = strlen(name);
	cur = top_var;
	while (cur) {
		if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
			if (cur->flg_read_only) {
				bb_error_msg("%s: readonly variable", name);
				return;
			}
		/* prev is ok to use here because 1st variable, HUSH_VERSION,
		 * is ro, and we cannot reach this code on the 1st pass */
			prev->next = cur->next;
			unsetenv(cur->varstr);
			if (!cur->max_len)
				free(cur->varstr);
			free(cur);
			return;
		}
		prev = cur;
		cur = cur->next;
	}
}

/* The src parameter allows us to peek forward to a possible &n syntax
 * for file descriptor duplication, e.g., "2>&1".
 * Return code is 0 normally, 1 if a syntax error is detected in src.
 * Resource errors (in xmalloc) cause the process to exit */
static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
	struct in_str *input)
{
	struct child_prog *child = ctx->child;
	struct redir_struct *redir = child->redirects;
	struct redir_struct *last_redir = NULL;

	/* Create a new redir_struct and drop it onto the end of the linked list */
	while (redir) {
		last_redir = redir;
		redir = redir->next;
	}
	redir = xzalloc(sizeof(struct redir_struct));
	/* redir->next = NULL; */
	/* redir->rd_filename = NULL; */
	if (last_redir) {
		last_redir->next = redir;
	} else {
		child->redirects = redir;
	}

	redir->rd_type = style;
	redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;

	debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);

	/* Check for a '2>&1' type redirect */
	redir->dup = redirect_dup_num(input);
	if (redir->dup == -2)
		return 1;  /* syntax error */
	if (redir->dup != -1) {
		/* Erik had a check here that the file descriptor in question
		 * is legit; I postpone that to "run time"
		 * A "-" representation of "close me" shows up as a -3 here */
		debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
	} else {
		/* We do _not_ try to open the file that src points to,
		 * since we need to return and let src be expanded first.
		 * Set ctx->pending_redirect, so we know what to do at the
		 * end of the next parsed word. */
		ctx->pending_redirect = redir;
	}
	return 0;
}

static struct pipe *new_pipe(void)
{
	struct pipe *pi;
	pi = xzalloc(sizeof(struct pipe));
	/*pi->followup = 0; - deliberately invalid value */
	/*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
	return pi;
}

static void initialize_context(struct p_context *ctx)
{
	memset(ctx, 0, sizeof(*ctx));
	ctx->pipe = ctx->list_head = new_pipe();
	/* Create the memory for child, roughly:
	 * ctx->pipe->progs = new struct child_prog;
	 * ctx->pipe->progs[0].family = ctx->pipe;
	 * ctx->child = &ctx->pipe->progs[0];
	 */
	done_command(ctx);
}

/* If a reserved word is found and processed, parse context is modified
 * and 1 is returned.
 * Handles if, then, elif, else, fi, for, while, until, do, done.
 * case, function, and select are obnoxious, save those for later.
 */
#if HAS_KEYWORDS
static int reserved_word(const o_string *word, struct p_context *ctx)
{
	struct reserved_combo {
		char literal[7];
		unsigned char res;
		int flag;
	};
	enum {
		FLAG_END   = (1 << RES_NONE ),
#if ENABLE_HUSH_IF
		FLAG_IF    = (1 << RES_IF   ),
		FLAG_THEN  = (1 << RES_THEN ),
		FLAG_ELIF  = (1 << RES_ELIF ),
		FLAG_ELSE  = (1 << RES_ELSE ),
		FLAG_FI    = (1 << RES_FI   ),
#endif
#if ENABLE_HUSH_LOOPS
		FLAG_FOR   = (1 << RES_FOR  ),
		FLAG_WHILE = (1 << RES_WHILE),
		FLAG_UNTIL = (1 << RES_UNTIL),
		FLAG_DO    = (1 << RES_DO   ),
		FLAG_DONE  = (1 << RES_DONE ),
		FLAG_IN    = (1 << RES_IN   ),
#endif
#if ENABLE_HUSH_CASE
		FLAG_MATCH = (1 << RES_MATCH),
		FLAG_ESAC  = (1 << RES_ESAC ),
#endif
		FLAG_START = (1 << RES_XXXX ),
	};
	/* Mostly a list of accepted follow-up reserved words.
	 * FLAG_END means we are done with the sequence, and are ready
	 * to turn the compound list into a command.
	 * FLAG_START means the word must start a new compound list.
	 */
	static const struct reserved_combo reserved_list[] = {
#if ENABLE_HUSH_IF
		{ "!",     RES_NONE,  0 },
		{ "if",    RES_IF,    FLAG_THEN | FLAG_START },
		{ "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
		{ "elif",  RES_ELIF,  FLAG_THEN },
		{ "else",  RES_ELSE,  FLAG_FI   },
		{ "fi",    RES_FI,    FLAG_END  },
#endif
#if ENABLE_HUSH_LOOPS
		{ "for",   RES_FOR,   FLAG_IN | FLAG_DO | FLAG_START },
		{ "while", RES_WHILE, FLAG_DO | FLAG_START },
		{ "until", RES_UNTIL, FLAG_DO | FLAG_START },
		{ "in",    RES_IN,    FLAG_DO   },
		{ "do",    RES_DO,    FLAG_DONE },
		{ "done",  RES_DONE,  FLAG_END  },
#endif
#if ENABLE_HUSH_CASE
		{ "case",  RES_CASE,  FLAG_MATCH | FLAG_START },
		{ "esac",  RES_ESAC,  FLAG_END  },
#endif
	};
#if ENABLE_HUSH_CASE
	static const struct reserved_combo reserved_match = {
		"" /* "match" */, RES_MATCH, FLAG_MATCH | FLAG_ESAC
	};
#endif
	const struct reserved_combo *r;

	for (r = reserved_list;	r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
		if (strcmp(word->data, r->literal) != 0)
			continue;
		debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
#if ENABLE_HUSH_CASE
		if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
			/* "case word IN ..." - IN part starts first match part */
			r = &reserved_match;
		else
#endif
		if (r->flag == 0) { /* '!' */
			if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
				syntax(NULL);
				IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
			}
			ctx->ctx_inverted = 1;
			return 1;
		}
		if (r->flag & FLAG_START) {
			struct p_context *new;
			debug_printf("push stack\n");
			new = xmalloc(sizeof(*new));
			*new = *ctx;   /* physical copy */
			initialize_context(ctx);
			ctx->stack = new;
		} else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
			syntax(NULL);
			ctx->ctx_res_w = RES_SNTX;
			return 1;
		}
		ctx->ctx_res_w = r->res;
		ctx->old_flag = r->flag;
		if (ctx->old_flag & FLAG_END) {
			struct p_context *old;
			debug_printf("pop stack\n");
			done_pipe(ctx, PIPE_SEQ);
			old = ctx->stack;
			old->child->group = ctx->list_head;
			old->child->subshell = 0;
			*ctx = *old;   /* physical copy */
			free(old);
		}
		return 1;
	}
	return 0;
}
#endif

/* Word is complete, look at it and update parsing context.
 * Normal return is 0. Syntax errors return 1. */
static int done_word(o_string *word, struct p_context *ctx)
{
	struct child_prog *child = ctx->child;

	/* If this word wasn't an assignment, next ones definitely
	 * can't be assignments. Even if they look like ones. */
	if (word->o_assignment != DEFINITELY_ASSIGNMENT) {
		word->o_assignment = NOT_ASSIGNMENT;
	} else {
		word->o_assignment = MAYBE_ASSIGNMENT;
	}

	debug_printf_parse("done_word entered: '%s' %p\n", word->data, child);
	if (word->length == 0 && word->nonnull == 0) {
		debug_printf_parse("done_word return 0: true null, ignored\n");
		return 0;
	}
	if (ctx->pending_redirect) {
		/* We do not glob in e.g. >*.tmp case. bash seems to glob here
		 * only if run as "bash", not "sh" */
		ctx->pending_redirect->rd_filename = xstrdup(word->data);
		word->o_assignment = NOT_ASSIGNMENT;
		debug_printf("word stored in rd_filename: '%s'\n", word->data);
	} else {
//		if (child->group) { /* TODO: example how to trigger? */
//			syntax(NULL);
//			debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
//			return 1;
//		}
#if HAS_KEYWORDS
#if ENABLE_HUSH_CASE
		if (ctx->ctx_dsemicolon) {
			/* already done when ctx_dsemicolon was set to 1 */
			/* ctx->ctx_res_w = RES_MATCH; */
			ctx->ctx_dsemicolon = 0;
		} else
#endif

		if (!child->argv /* if it's the first word... */
#if ENABLE_HUSH_LOOPS
		 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
		 && ctx->ctx_res_w != RES_IN
#endif
		) {
			debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
			if (reserved_word(word, ctx)) {
				o_reset(word);
				word->o_assignment = NOT_ASSIGNMENT;
				debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
				return (ctx->ctx_res_w == RES_SNTX);
			}
		}
#endif
		if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
		 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
		 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
		 /* (otherwise it's known to be not empty and is already safe) */
		) {
			/* exclude "$@" - it can expand to no word despite "" */
			char *p = word->data;
			while (p[0] == SPECIAL_VAR_SYMBOL
			    && (p[1] & 0x7f) == '@'
			    && p[2] == SPECIAL_VAR_SYMBOL
			) {
				p += 3;
			}
			if (p == word->data || p[0] != '\0') {
				/* saw no "$@", or not only "$@" but some
				 * real text is there too */
				/* insert "empty variable" reference, this makes
				 * e.g. "", $empty"" etc to not disappear */
				o_addchr(word, SPECIAL_VAR_SYMBOL);
				o_addchr(word, SPECIAL_VAR_SYMBOL);
			}
		}
		child->argv = add_malloced_string_to_strings(child->argv, xstrdup(word->data));
		debug_print_strings("word appended to argv", child->argv);
	}

	o_reset(word);
	ctx->pending_redirect = NULL;

#if ENABLE_HUSH_LOOPS
	/* Force FOR to have just one word (variable name) */
	/* NB: basically, this makes hush see "for v in ..." syntax as if
	 * as it is "for v; in ...". FOR and IN become two pipe structs
	 * in parse tree. */
	if (ctx->ctx_res_w == RES_FOR) {
//TODO: check that child->argv[0] is a valid variable name!
		done_pipe(ctx, PIPE_SEQ);
	}
#endif
#if ENABLE_HUSH_CASE
	/* Force CASE to have just one word */
	if (ctx->ctx_res_w == RES_CASE) {
		done_pipe(ctx, PIPE_SEQ);
	}
#endif
	debug_printf_parse("done_word return 0\n");
	return 0;
}

/* Command (member of a pipe) is complete. The only possible error here
 * is out of memory, in which case xmalloc exits. */
static int done_command(struct p_context *ctx)
{
	/* The child is really already in the pipe structure, so
	 * advance the pipe counter and make a new, null child. */
	struct pipe *pi = ctx->pipe;
	struct child_prog *child = ctx->child;

	if (child) {
		if (child->group == NULL
		 && child->argv == NULL
		 && child->redirects == NULL
		) {
			debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
			return pi->num_progs;
		}
		pi->num_progs++;
		debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
	} else {
		debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
	}

	/* Only real trickiness here is that the uncommitted
	 * child structure is not counted in pi->num_progs. */
	pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
	child = &pi->progs[pi->num_progs];

	memset(child, 0, sizeof(*child));
	child->family = pi;

	ctx->child = child;
	/* but ctx->pipe and ctx->list_head remain unchanged */

	return pi->num_progs; /* used only for 0/nonzero check */
}

static void done_pipe(struct p_context *ctx, pipe_style type)
{
	int not_null;

	debug_printf_parse("done_pipe entered, followup %d\n", type);
	not_null = done_command(ctx);  /* implicit closure of previous command */
	ctx->pipe->followup = type;
	IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
	IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
	IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
	/* Without this check, even just <enter> on command line generates
	 * tree of three NOPs (!). Which is harmless but annoying.
	 * IOW: it is safe to do it unconditionally.
	 * RES_NONE case is for "for a in; do ..." (empty IN set)
	 * to work, possibly other cases too. */
	if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
		struct pipe *new_p = new_pipe();
		ctx->pipe->next = new_p;
		ctx->pipe = new_p;
		ctx->child = NULL; /* needed! */
		/* RES_IF, RES_WHILE etc are "sticky" -
		 * they remain set for commands inside if/while.
		 * This is used to control execution.
		 * RES_FOR and RES_IN are NOT sticky (needed to support
		 * cases where variable or value happens to match a keyword):
		 */
#if ENABLE_HUSH_LOOPS
		if (ctx->ctx_res_w == RES_FOR
		 || ctx->ctx_res_w == RES_IN)
			ctx->ctx_res_w = RES_NONE;
#endif
#if ENABLE_HUSH_CASE
		if (ctx->ctx_res_w == RES_MATCH)
			ctx->ctx_res_w = RES_CASEI;
#endif
		/* Create the memory for child, roughly:
		 * ctx->pipe->progs = new struct child_prog;
		 * ctx->pipe->progs[0].family = ctx->pipe;
		 * ctx->child = &ctx->pipe->progs[0];
		 */
		done_command(ctx);
	}
	debug_printf_parse("done_pipe return\n");
}

/* Peek ahead in the in_str to find out if we have a "&n" construct,
 * as in "2>&1", that represents duplicating a file descriptor.
 * Return either -2 (syntax error), -1 (no &), or the number found.
 */
static int redirect_dup_num(struct in_str *input)
{
	int ch, d = 0, ok = 0;
	ch = i_peek(input);
	if (ch != '&') return -1;

	i_getch(input);  /* get the & */
	ch = i_peek(input);
	if (ch == '-') {
		i_getch(input);
		return -3;  /* "-" represents "close me" */
	}
	while (isdigit(ch)) {
		d = d*10 + (ch-'0');
		ok = 1;
		i_getch(input);
		ch = i_peek(input);
	}
	if (ok) return d;

	bb_error_msg("ambiguous redirect");
	return -2;
}

/* If a redirect is immediately preceded by a number, that number is
 * supposed to tell which file descriptor to redirect.  This routine
 * looks for such preceding numbers.  In an ideal world this routine
 * needs to handle all the following classes of redirects...
 *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
 *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
 *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
 *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
 * A -1 output from this program means no valid number was found, so the
 * caller should use the appropriate default for this redirection.
 */
static int redirect_opt_num(o_string *o)
{
	int num;

	if (o->length == 0)
		return -1;
	for (num = 0; num < o->length; num++) {
		if (!isdigit(o->data[num])) {
			return -1;
		}
	}
	num = atoi(o->data);
	o_reset(o);
	return num;
}

#if ENABLE_HUSH_TICK
static FILE *generate_stream_from_list(struct pipe *head)
{
	FILE *pf;
	int pid, channel[2];

	xpipe(channel);
/* *** NOMMU WARNING *** */
/* By using vfork here, we suspend parent till child exits or execs.
 * If child will not do it before it fills the pipe, it can block forever
 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
 * Try this script:
 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
 * huge=`cat TESTFILE` # will block here forever
 * echo OK
 */
	pid = BB_MMU ? fork() : vfork();
	if (pid < 0)
		bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
	if (pid == 0) { /* child */
		if (ENABLE_HUSH_JOB)
			die_sleep = 0; /* let nofork's xfuncs die */
		close(channel[0]); /* NB: close _first_, then move fd! */
		xmove_fd(channel[1], 1);
		/* Prevent it from trying to handle ctrl-z etc */
#if ENABLE_HUSH_JOB
		run_list_level = 1;
#endif
		/* Process substitution is not considered to be usual
		 * 'command execution'.
		 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
		/* Not needed, we are relying on it being disabled
		 * everywhere outside actual command execution. */
		/*set_jobctrl_sighandler(SIG_IGN);*/
		set_misc_sighandler(SIG_DFL);
		/* Freeing 'head' here would break NOMMU. */
		_exit(run_list(head));
	}
	close(channel[1]);
	pf = fdopen(channel[0], "r");
	return pf;
	/* 'head' is freed by the caller */
}

/* Return code is exit status of the process that is run. */
static int process_command_subs(o_string *dest,
		struct in_str *input,
		const char *subst_end)
{
	int retcode, ch, eol_cnt;
	o_string result = NULL_O_STRING;
	struct p_context inner;
	FILE *p;
	struct in_str pipe_str;

	initialize_context(&inner);

	/* Recursion to generate command */
	retcode = parse_stream(&result, &inner, input, subst_end);
	if (retcode != 0)
		return retcode;  /* syntax error or EOF */
	done_word(&result, &inner);
	done_pipe(&inner, PIPE_SEQ);
	o_free(&result);

	p = generate_stream_from_list(inner.list_head);
	if (p == NULL)
		return 1;
	close_on_exec_on(fileno(p));
	setup_file_in_str(&pipe_str, p);

	/* Now send results of command back into original context */
	eol_cnt = 0;
	while ((ch = i_getch(&pipe_str)) != EOF) {
		if (ch == '\n') {
			eol_cnt++;
			continue;
		}
		while (eol_cnt) {
			o_addchr(dest, '\n');
			eol_cnt--;
		}
//		/* Even unquoted `echo '\'` results in two backslashes
//		 * (which are converted into one by globbing later) */
//		if (!dest->o_quote && ch == '\\') {
//			o_addchr(dest, ch);
//		}
		o_addQchr(dest, ch);
	}

	debug_printf("done reading from pipe, pclose()ing\n");
	/* This is the step that wait()s for the child.  Should be pretty
	 * safe, since we just read an EOF from its stdout.  We could try
	 * to do better, by using wait(), and keeping track of background jobs
	 * at the same time.  That would be a lot of work, and contrary
	 * to the KISS philosophy of this program. */
	retcode = fclose(p);
	free_pipe_list(inner.list_head, /* indent: */ 0);
	debug_printf("closed FILE from child, retcode=%d\n", retcode);
	return retcode;
}
#endif

static int parse_group(o_string *dest, struct p_context *ctx,
	struct in_str *input, int ch)
{
	int rcode;
	const char *endch = NULL;
	struct p_context sub;
	struct child_prog *child = ctx->child;

	debug_printf_parse("parse_group entered\n");
	if (child->argv) {
		syntax(NULL);
		debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
		return 1;
	}
	initialize_context(&sub);
	endch = "}";
	if (ch == '(') {
		endch = ")";
		child->subshell = 1;
	}
	rcode = parse_stream(dest, &sub, input, endch);
	if (rcode == 0) {
		done_word(dest, &sub); /* finish off the final word in the subcontext */
		done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
		child->group = sub.list_head;
	}
	debug_printf_parse("parse_group return %d\n", rcode);
	return rcode;
	/* child remains "open", available for possible redirects */
}

/* Basically useful version until someone wants to get fancier,
 * see the bash man page under "Parameter Expansion" */
static const char *lookup_param(const char *src)
{
	struct variable *var = get_local_var(src);
	if (var)
		return strchr(var->varstr, '=') + 1;
	return NULL;
}

#if ENABLE_HUSH_TICK
/* Subroutines for copying $(...) and `...` things */
static void add_till_backquote(o_string *dest, struct in_str *input);
/* '...' */
static void add_till_single_quote(o_string *dest, struct in_str *input)
{
	while (1) {
		int ch = i_getch(input);
		if (ch == EOF)
			break;
		if (ch == '\'')
			break;
		o_addchr(dest, ch);
	}
}
/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
static void add_till_double_quote(o_string *dest, struct in_str *input)
{
	while (1) {
		int ch = i_getch(input);
		if (ch == '"')
			break;
		if (ch == '\\') {  /* \x. Copy both chars. */
			o_addchr(dest, ch);
			ch = i_getch(input);
		}
		if (ch == EOF)
			break;
		o_addchr(dest, ch);
		if (ch == '`') {
			add_till_backquote(dest, input);
			o_addchr(dest, ch);
			continue;
		}
		//if (ch == '$') ...
	}
}
/* Process `cmd` - copy contents until "`" is seen. Complicated by
 * \` quoting.
 * "Within the backquoted style of command substitution, backslash
 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
 * The search for the matching backquote shall be satisfied by the first
 * backquote found without a preceding backslash; during this search,
 * if a non-escaped backquote is encountered within a shell comment,
 * a here-document, an embedded command substitution of the $(command)
 * form, or a quoted string, undefined results occur. A single-quoted
 * or double-quoted string that begins, but does not end, within the
 * "`...`" sequence produces undefined results."
 * Example                               Output
 * echo `echo '\'TEST\`echo ZZ\`BEST`    \TESTZZBEST
 */
static void add_till_backquote(o_string *dest, struct in_str *input)
{
	while (1) {
		int ch = i_getch(input);
		if (ch == '`')
			break;
		if (ch == '\\') {  /* \x. Copy both chars unless it is \` */
			int ch2 = i_getch(input);
			if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
				o_addchr(dest, ch);
			ch = ch2;
		}
		if (ch == EOF)
			break;
		o_addchr(dest, ch);
	}
}
/* Process $(cmd) - copy contents until ")" is seen. Complicated by
 * quoting and nested ()s.
 * "With the $(command) style of command substitution, all characters
 * following the open parenthesis to the matching closing parenthesis
 * constitute the command. Any valid shell script can be used for command,
 * except a script consisting solely of redirections which produces
 * unspecified results."
 * Example                              Output
 * echo $(echo '(TEST)' BEST)           (TEST) BEST
 * echo $(echo 'TEST)' BEST)            TEST) BEST
 * echo $(echo \(\(TEST\) BEST)         ((TEST) BEST
 */
static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
{
	int count = 0;
	while (1) {
		int ch = i_getch(input);
		if (ch == EOF)
			break;
		if (ch == '(')
			count++;
		if (ch == ')')
			if (--count < 0)
				break;
		o_addchr(dest, ch);
		if (ch == '\'') {
			add_till_single_quote(dest, input);
			o_addchr(dest, ch);
			continue;
		}
		if (ch == '"') {
			add_till_double_quote(dest, input);
			o_addchr(dest, ch);
			continue;
		}
		if (ch == '\\') { /* \x. Copy verbatim. Important for  \(, \) */
			ch = i_getch(input);
			if (ch == EOF)
				break;
			o_addchr(dest, ch);
			continue;
		}
	}
}
#endif /* ENABLE_HUSH_TICK */

/* Return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct in_str *input)
{
	int ch = i_peek(input);  /* first character after the $ */
	unsigned char quote_mask = dest->o_quote ? 0x80 : 0;

	debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
	if (isalpha(ch)) {
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		while (1) {
			debug_printf_parse(": '%c'\n", ch);
			i_getch(input);
			o_addchr(dest, ch | quote_mask);
			quote_mask = 0;
			ch = i_peek(input);
			if (!isalnum(ch) && ch != '_')
				break;
		}
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
	} else if (isdigit(ch)) {
 make_one_char_var:
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		debug_printf_parse(": '%c'\n", ch);
		i_getch(input);
		o_addchr(dest, ch | quote_mask);
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
	} else switch (ch) {
		case '$': /* pid */
		case '!': /* last bg pid */
		case '?': /* last exit code */
		case '#': /* number of args */
		case '*': /* args */
		case '@': /* args */
			goto make_one_char_var;
		case '{':
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			i_getch(input);
			/* XXX maybe someone will try to escape the '}' */
			while (1) {
				ch = i_getch(input);
				if (ch == '}')
					break;
				if (!isalnum(ch) && ch != '_') {
					syntax("unterminated ${name}");
					debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
					return 1;
				}
				debug_printf_parse(": '%c'\n", ch);
				o_addchr(dest, ch | quote_mask);
				quote_mask = 0;
			}
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			break;
#if ENABLE_HUSH_TICK
		case '(': {
			//int pos = dest->length;
			i_getch(input);
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			o_addchr(dest, quote_mask | '`');
			add_till_closing_curly_brace(dest, input);
			//debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			break;
		}
#endif
		case '-':
		case '_':
			/* still unhandled, but should be eventually */
			bb_error_msg("unhandled syntax: $%c", ch);
			return 1;
			break;
		default:
			o_addQchr(dest, '$');
	}
	debug_printf_parse("handle_dollar return 0\n");
	return 0;
}

/* Scan input, call done_word() whenever full IFS delimited word was seen.
 * Call done_pipe if '\n' was seen (and end_trigger != NULL).
 * Return code is 0 if end_trigger char is met,
 * -1 on EOF (but if end_trigger == NULL then return 0),
 * 1 for syntax error */
static int parse_stream(o_string *dest, struct p_context *ctx,
	struct in_str *input, const char *end_trigger)
{
	int ch, m;
	int redir_fd;
	redir_type redir_style;
	int shadow_quote = dest->o_quote;
	int next;

	/* Only double-quote state is handled in the state variable dest->o_quote.
	 * A single-quote triggers a bypass of the main loop until its mate is
	 * found.  When recursing, quote state is passed in via dest->o_quote. */

	debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);

	while (1) {
		m = CHAR_IFS;
		next = '\0';
		ch = i_getch(input);
		if (ch != EOF) {
			m = charmap[ch];
			if (ch != '\n') {
				next = i_peek(input);
			}
		}
		debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
						ch, ch, m, dest->o_quote);
		if (m == CHAR_ORDINARY
		 || (m != CHAR_SPECIAL && shadow_quote)
		) {
			if (ch == EOF) {
				syntax("unterminated \"");
				debug_printf_parse("parse_stream return 1: unterminated \"\n");
				return 1;
			}
			o_addQchr(dest, ch);
			if (dest->o_assignment == MAYBE_ASSIGNMENT
			 && ch == '='
			 && is_assignment(dest->data)
			) {
				dest->o_assignment = DEFINITELY_ASSIGNMENT;
			}
			continue;
		}
		if (m == CHAR_IFS) {
			if (done_word(dest, ctx)) {
				debug_printf_parse("parse_stream return 1: done_word!=0\n");
				return 1;
			}
			if (ch == EOF)
				break;
			/* If we aren't performing a substitution, treat
			 * a newline as a command separator.
			 * [why we don't handle it exactly like ';'? --vda] */
			if (end_trigger && ch == '\n') {
				done_pipe(ctx, PIPE_SEQ);
			}
		}
		if (end_trigger) {
			if (!shadow_quote && strchr(end_trigger, ch)) {
				/* Special case: (...word) makes last word terminate,
				 * as if ';' is seen */
				if (ch == ')') {
					done_word(dest, ctx);
//err chk?
					done_pipe(ctx, PIPE_SEQ);
				}
				if (!HAS_KEYWORDS
				 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
				) {
					debug_printf_parse("parse_stream return 0: end_trigger char found\n");
					return 0;
				}
			}
		}
		if (m == CHAR_IFS)
			continue;

		if (dest->o_assignment == MAYBE_ASSIGNMENT) {
			/* ch is a special char and thus this word
			 * cannot be an assignment: */
			dest->o_assignment = NOT_ASSIGNMENT;
		}

		switch (ch) {
		case '#':
			if (dest->length == 0 && !shadow_quote) {
				while (1) {
					ch = i_peek(input);
					if (ch == EOF || ch == '\n')
						break;
					i_getch(input);
				}
			} else {
				o_addQchr(dest, ch);
			}
			break;
		case '\\':
			if (next == EOF) {
				syntax("\\<eof>");
				debug_printf_parse("parse_stream return 1: \\<eof>\n");
				return 1;
			}
			/* bash:
			 * "The backslash retains its special meaning [in "..."]
			 * only when followed by one of the following characters:
			 * $, `, ", \, or <newline>.  A double quote may be quoted
			 * within double quotes by preceding it with a  backslash.
			 * If enabled, history expansion will be performed unless
			 * an ! appearing in double quotes is escaped using
			 * a backslash. The backslash preceding the ! is not removed."
			 */
			if (shadow_quote) { //NOT SURE   dest->o_quote) {
				if (strchr("$`\"\\", next) != NULL) {
					o_addqchr(dest, i_getch(input));
				} else {
					o_addqchr(dest, '\\');
				}
			} else {
				o_addchr(dest, '\\');
				o_addchr(dest, i_getch(input));
			}
			break;
		case '$':
			if (handle_dollar(dest, input) != 0) {
				debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
				return 1;
			}
			break;
		case '\'':
			dest->nonnull = 1;
			while (1) {
				ch = i_getch(input);
				if (ch == EOF) {
					syntax("unterminated '");
					debug_printf_parse("parse_stream return 1: unterminated '\n");
					return 1;
				}
				if (ch == '\'')
					break;
				if (dest->o_assignment == NOT_ASSIGNMENT)
					o_addqchr(dest, ch);
				else
					o_addchr(dest, ch);
			}
			break;
		case '"':
			dest->nonnull = 1;
			shadow_quote ^= 1; /* invert */
			if (dest->o_assignment == NOT_ASSIGNMENT)
				dest->o_quote ^= 1;
			break;
#if ENABLE_HUSH_TICK
		case '`': {
			//int pos = dest->length;
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
			add_till_backquote(dest, input);
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
			break;
		}
#endif
		case '>':
			redir_fd = redirect_opt_num(dest);
			done_word(dest, ctx);
			redir_style = REDIRECT_OVERWRITE;
			if (next == '>') {
				redir_style = REDIRECT_APPEND;
				i_getch(input);
			}
#if 0
			else if (next == '(') {
				syntax(">(process) not supported");
				debug_printf_parse("parse_stream return 1: >(process) not supported\n");
				return 1;
			}
#endif
			setup_redirect(ctx, redir_fd, redir_style, input);
			break;
		case '<':
			redir_fd = redirect_opt_num(dest);
			done_word(dest, ctx);
			redir_style = REDIRECT_INPUT;
			if (next == '<') {
				redir_style = REDIRECT_HEREIS;
				i_getch(input);
			} else if (next == '>') {
				redir_style = REDIRECT_IO;
				i_getch(input);
			}
#if 0
			else if (next == '(') {
				syntax("<(process) not supported");
				debug_printf_parse("parse_stream return 1: <(process) not supported\n");
				return 1;
			}
#endif
			setup_redirect(ctx, redir_fd, redir_style, input);
			break;
		case ';':
#if ENABLE_HUSH_CASE
 case_semi:
#endif
			done_word(dest, ctx);
			done_pipe(ctx, PIPE_SEQ);
#if ENABLE_HUSH_CASE
			/* Eat multiple semicolons, detect
			 * whether it means something special */
			while (1) {
				ch = i_peek(input);
				if (ch != ';')
					break;
				i_getch(input);
				if (ctx->ctx_res_w == RES_CASEI) {
					ctx->ctx_dsemicolon = 1;
					ctx->ctx_res_w = RES_MATCH;
					break;
				}
			}
#endif
			break;
		case '&':
			done_word(dest, ctx);
			if (next == '&') {
				i_getch(input);
				done_pipe(ctx, PIPE_AND);
			} else {
				done_pipe(ctx, PIPE_BG);
			}
			break;
		case '|':
			done_word(dest, ctx);
			if (next == '|') {
				i_getch(input);
				done_pipe(ctx, PIPE_OR);
			} else {
				/* we could pick up a file descriptor choice here
				 * with redirect_opt_num(), but bash doesn't do it.
				 * "echo foo 2| cat" yields "foo 2". */
				done_command(ctx);
			}
			break;
		case '(':
#if ENABLE_HUSH_CASE
			if (dest->length == 0 // && argv[0] == NULL
			 && ctx->ctx_res_w == RES_MATCH
			) {
				continue;
			}
#endif
		case '{':
			if (parse_group(dest, ctx, input, ch) != 0) {
				debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
				return 1;
			}
			break;
		case ')':
#if ENABLE_HUSH_CASE
			if (ctx->ctx_res_w == RES_MATCH)
				goto case_semi;
#endif
		case '}':
			/* proper use of this character is caught by end_trigger */
			syntax("unexpected } or )");
			debug_printf_parse("parse_stream return 1: unexpected '}'\n");
			return 1;
		default:
			if (HUSH_DEBUG)
				bb_error_msg_and_die("BUG: unexpected %c\n", ch);
		}
	} /* while (1) */
	debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
	if (end_trigger)
		return -1;
	return 0;
}

static void set_in_charmap(const char *set, int code)
{
	while (*set)
		charmap[(unsigned char)*set++] = code;
}

static void update_charmap(void)
{
	/* char *ifs and char charmap[256] are both globals. */
	ifs = getenv("IFS");
	if (ifs == NULL)
		ifs = " \t\n";
	/* Precompute a list of 'flow through' behavior so it can be treated
	 * quickly up front.  Computation is necessary because of IFS.
	 * Special case handling of IFS == " \t\n" is not implemented.
	 * The charmap[] array only really needs two bits each,
	 * and on most machines that would be faster (reduced L1 cache use).
	 */
	memset(charmap, CHAR_ORDINARY, sizeof(charmap));
#if ENABLE_HUSH_TICK
	set_in_charmap("\\$\"`", CHAR_SPECIAL);
#else
	set_in_charmap("\\$\"", CHAR_SPECIAL);
#endif
	set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
	set_in_charmap(ifs, CHAR_IFS);  /* are ordinary if quoted */
}

/* Most recursion does not come through here, the exception is
 * from builtin_source() and builtin_eval() */
static int parse_and_run_stream(struct in_str *inp, int parse_flag)
{
	struct p_context ctx;
	o_string temp = NULL_O_STRING;
	int rcode;

	do {
		initialize_context(&ctx);
		update_charmap();
#if ENABLE_HUSH_INTERACTIVE
		inp->promptmode = 0; /* PS1 */
#endif
		/* We will stop & execute after each ';' or '\n'.
		 * Example: "sleep 9999; echo TEST" + ctrl-C:
		 * TEST should be printed */
		rcode = parse_stream(&temp, &ctx, inp, ";\n");
#if HAS_KEYWORDS
		if (rcode != 1 && ctx.old_flag != 0) {
			syntax(NULL);
		}
#endif
		if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
			done_word(&temp, &ctx);
			done_pipe(&ctx, PIPE_SEQ);
			debug_print_tree(ctx.list_head, 0);
			debug_printf_exec("parse_stream_outer: run_and_free_list\n");
			run_and_free_list(ctx.list_head);
		} else {
			/* We arrive here also if rcode == 1 (error in parse_stream) */
#if HAS_KEYWORDS
			if (ctx.old_flag != 0) {
				free(ctx.stack);
				o_reset(&temp);
			}
#endif
			/*temp.nonnull = 0; - o_free does it below */
			/*temp.o_quote = 0; - o_free does it below */
			free_pipe_list(ctx.list_head, /* indent: */ 0);
			/* Discard all unprocessed line input, force prompt on */
			inp->p = NULL;
#if ENABLE_HUSH_INTERACTIVE
			inp->promptme = 1;
#endif
		}
		o_free(&temp);
		/* loop on syntax errors, return on EOF: */
	} while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
	return 0;
}

static int parse_and_run_string(const char *s, int parse_flag)
{
	struct in_str input;
	setup_string_in_str(&input, s);
	return parse_and_run_stream(&input, parse_flag);
}

static int parse_and_run_file(FILE *f)
{
	int rcode;
	struct in_str input;
	setup_file_in_str(&input, f);
	rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
	return rcode;
}

#if ENABLE_HUSH_JOB
/* Make sure we have a controlling tty.  If we get started under a job
 * aware app (like bash for example), make sure we are now in charge so
 * we don't fight over who gets the foreground */
static void setup_job_control(void)
{
	pid_t shell_pgrp;

	saved_task_pgrp = shell_pgrp = getpgrp();
	debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
	close_on_exec_on(interactive_fd);

	/* If we were ran as 'hush &',
	 * sleep until we are in the foreground.  */
	while (tcgetpgrp(interactive_fd) != shell_pgrp) {
		/* Send TTIN to ourself (should stop us) */
		kill(- shell_pgrp, SIGTTIN);
		shell_pgrp = getpgrp();
	}

	/* Ignore job-control and misc signals.  */
	set_jobctrl_sighandler(SIG_IGN);
	set_misc_sighandler(SIG_IGN);
//huh?	signal(SIGCHLD, SIG_IGN);

	/* We _must_ restore tty pgrp on fatal signals */
	set_fatal_sighandler(sigexit);

	/* Put ourselves in our own process group.  */
	setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
	/* Grab control of the terminal.  */
	tcsetpgrp(interactive_fd, getpid());
}
#endif


int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hush_main(int argc, char **argv)
{
	static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
	static const struct variable const_shell_ver = {
		.next = NULL,
		.varstr = (char*)version_str,
		.max_len = 1, /* 0 can provoke free(name) */
		.flg_export = 1,
		.flg_read_only = 1,
	};

	int opt;
	FILE *input;
	char **e;
	struct variable *cur_var;

	INIT_G();

	root_pid = getpid();

	/* Deal with HUSH_VERSION */
	shell_ver = const_shell_ver; /* copying struct here */
	top_var = &shell_ver;
	unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
	/* Initialize our shell local variables with the values
	 * currently living in the environment */
	cur_var = top_var;
	e = environ;
	if (e) while (*e) {
		char *value = strchr(*e, '=');
		if (value) { /* paranoia */
			cur_var->next = xzalloc(sizeof(*cur_var));
			cur_var = cur_var->next;
			cur_var->varstr = *e;
			cur_var->max_len = strlen(*e);
			cur_var->flg_export = 1;
		}
		e++;
	}
	putenv((char *)version_str); /* reinstate HUSH_VERSION */

#if ENABLE_FEATURE_EDITING
	line_input_state = new_line_input_t(FOR_SHELL);
#endif
	/* XXX what should these be while sourcing /etc/profile? */
	global_argc = argc;
	global_argv = argv;
	/* Initialize some more globals to non-zero values */
	set_cwd();
#if ENABLE_HUSH_INTERACTIVE
#if ENABLE_FEATURE_EDITING
	cmdedit_set_initial_prompt();
#endif
	PS2 = "> ";
#endif

	if (EXIT_SUCCESS) /* otherwise is already done */
		last_return_code = EXIT_SUCCESS;

	if (argv[0] && argv[0][0] == '-') {
		debug_printf("sourcing /etc/profile\n");
		input = fopen("/etc/profile", "r");
		if (input != NULL) {
			close_on_exec_on(fileno(input));
			parse_and_run_file(input);
			fclose(input);
		}
	}
	input = stdin;

	while ((opt = getopt(argc, argv, "c:xif")) > 0) {
		switch (opt) {
		case 'c':
			global_argv = argv + optind;
			global_argc = argc - optind;
			opt = parse_and_run_string(optarg, 0 /* parse_flag */);
			goto final_return;
		case 'i':
			/* Well, we cannot just declare interactiveness,
			 * we have to have some stuff (ctty, etc) */
			/* interactive_fd++; */
			break;
		case 'f':
			fake_mode = 1;
			break;
		default:
#ifndef BB_VER
			fprintf(stderr, "Usage: sh [FILE]...\n"
					"   or: sh -c command [args]...\n\n");
			exit(EXIT_FAILURE);
#else
			bb_show_usage();
#endif
		}
	}
#if ENABLE_HUSH_JOB
	/* A shell is interactive if the '-i' flag was given, or if all of
	 * the following conditions are met:
	 *    no -c command
	 *    no arguments remaining or the -s flag given
	 *    standard input is a terminal
	 *    standard output is a terminal
	 *    Refer to Posix.2, the description of the 'sh' utility. */
	if (argv[optind] == NULL && input == stdin
	 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
	) {
		saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
		debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
		if (saved_tty_pgrp >= 0) {
			/* try to dup to high fd#, >= 255 */
			interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
			if (interactive_fd < 0) {
				/* try to dup to any fd */
				interactive_fd = dup(STDIN_FILENO);
				if (interactive_fd < 0)
					/* give up */
					interactive_fd = 0;
			}
			// TODO: track & disallow any attempts of user
			// to (inadvertently) close/redirect it
		}
	}
	debug_printf("interactive_fd=%d\n", interactive_fd);
	if (interactive_fd) {
		fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
		/* Looks like they want an interactive shell */
		setup_job_control();
		/* -1 is special - makes xfuncs longjmp, not exit
		 * (we reset die_sleep = 0 whereever we [v]fork) */
		die_sleep = -1;
		if (setjmp(die_jmp)) {
			/* xfunc has failed! die die die */
			hush_exit(xfunc_error_retval);
		}
#if !ENABLE_FEATURE_SH_EXTRA_QUIET
		printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
		printf("Enter 'help' for a list of built-in commands.\n\n");
#endif
	}
#elif ENABLE_HUSH_INTERACTIVE
/* no job control compiled, only prompt/line editing */
	if (argv[optind] == NULL && input == stdin
	 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
	) {
		interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
		if (interactive_fd < 0) {
			/* try to dup to any fd */
			interactive_fd = dup(STDIN_FILENO);
			if (interactive_fd < 0)
				/* give up */
				interactive_fd = 0;
		}
		if (interactive_fd) {
			fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
			set_misc_sighandler(SIG_IGN);
		}
	}
#endif

	if (argv[optind] == NULL) {
		opt = parse_and_run_file(stdin);
	} else {
		debug_printf("\nrunning script '%s'\n", argv[optind]);
		global_argv = argv + optind;
		global_argc = argc - optind;
		input = xfopen(argv[optind], "r");
		fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
		opt = parse_and_run_file(input);
	}

 final_return:

#if ENABLE_FEATURE_CLEAN_UP
	fclose(input);
	if (cwd != bb_msg_unknown)
		free((char*)cwd);
	cur_var = top_var->next;
	while (cur_var) {
		struct variable *tmp = cur_var;
		if (!cur_var->max_len)
			free(cur_var->varstr);
		cur_var = cur_var->next;
		free(tmp);
	}
#endif
	hush_exit(opt ? opt : last_return_code);
}


#if ENABLE_LASH
int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int lash_main(int argc, char **argv)
{
	//bb_error_msg("lash is deprecated, please use hush instead");
	return hush_main(argc, argv);
}
#endif


/*
 * Built-ins
 */
static int builtin_true(char **argv UNUSED_PARAM)
{
	return 0;
}

static int builtin_test(char **argv)
{
	int argc = 0;
	while (*argv) {
		argc++;
		argv++;
	}
	return test_main(argc, argv - argc);
}

static int builtin_echo(char **argv)
{
	int argc = 0;
	while (*argv) {
		argc++;
		argv++;
	}
	return echo_main(argc, argv - argc);
}

static int builtin_eval(char **argv)
{
	int rcode = EXIT_SUCCESS;

	if (argv[1]) {
		char *str = expand_strvec_to_string(argv + 1);
		parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
		free(str);
		rcode = last_return_code;
	}
	return rcode;
}

static int builtin_cd(char **argv)
{
	const char *newdir;
	if (argv[1] == NULL) {
		// bash does nothing (exitcode 0) if HOME is ""; if it's unset,
		// bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
		newdir = getenv("HOME") ? : "/";
	} else
		newdir = argv[1];
	if (chdir(newdir)) {
		printf("cd: %s: %s\n", newdir, strerror(errno));
		return EXIT_FAILURE;
	}
	set_cwd();
	return EXIT_SUCCESS;
}

static int builtin_exec(char **argv)
{
	if (argv[1] == NULL)
		return EXIT_SUCCESS; /* bash does this */
	{
#if !BB_MMU
		char **ptrs2free = alloc_ptrs(argv);
#endif
// FIXME: if exec fails, bash does NOT exit! We do...
		pseudo_exec_argv(ptrs2free, argv + 1);
		/* never returns */
	}
}

static int builtin_exit(char **argv)
{
// TODO: bash does it ONLY on top-level sh exit (+interacive only?)
	//puts("exit"); /* bash does it */
// TODO: warn if we have background jobs: "There are stopped jobs"
// On second consecutive 'exit', exit anyway.
	if (argv[1] == NULL)
		hush_exit(last_return_code);
	/* mimic bash: exit 123abc == exit 255 + error msg */
	xfunc_error_retval = 255;
	/* bash: exit -2 == exit 254, no error msg */
	hush_exit(xatoi(argv[1]) & 0xff);
}

static int builtin_export(char **argv)
{
	const char *value;
	char *name = argv[1];

	if (name == NULL) {
		// TODO:
		// ash emits: export VAR='VAL'
		// bash: declare -x VAR="VAL"
		// (both also escape as needed (quotes, $, etc))
		char **e = environ;
		if (e)
			while (*e)
				puts(*e++);
		return EXIT_SUCCESS;
	}

	value = strchr(name, '=');
	if (!value) {
		/* They are exporting something without a =VALUE */
		struct variable *var;

		var = get_local_var(name);
		if (var) {
			var->flg_export = 1;
			putenv(var->varstr);
		}
		/* bash does not return an error when trying to export
		 * an undefined variable.  Do likewise. */
		return EXIT_SUCCESS;
	}

	set_local_var(xstrdup(name), 1);
	return EXIT_SUCCESS;
}

#if ENABLE_HUSH_JOB
/* built-in 'fg' and 'bg' handler */
static int builtin_fg_bg(char **argv)
{
	int i, jobnum;
	struct pipe *pi;

	if (!interactive_fd)
		return EXIT_FAILURE;
	/* If they gave us no args, assume they want the last backgrounded task */
	if (!argv[1]) {
		for (pi = job_list; pi; pi = pi->next) {
			if (pi->jobid == last_jobid) {
				goto found;
			}
		}
		bb_error_msg("%s: no current job", argv[0]);
		return EXIT_FAILURE;
	}
	if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
		bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
		return EXIT_FAILURE;
	}
	for (pi = job_list; pi; pi = pi->next) {
		if (pi->jobid == jobnum) {
			goto found;
		}
	}
	bb_error_msg("%s: %d: no such job", argv[0], jobnum);
	return EXIT_FAILURE;
 found:
	// TODO: bash prints a string representation
	// of job being foregrounded (like "sleep 1 | cat")
	if (*argv[0] == 'f') {
		/* Put the job into the foreground.  */
		tcsetpgrp(interactive_fd, pi->pgrp);
	}

	/* Restart the processes in the job */
	debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
	for (i = 0; i < pi->num_progs; i++) {
		debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
		pi->progs[i].is_stopped = 0;
	}
	pi->stopped_progs = 0;

	i = kill(- pi->pgrp, SIGCONT);
	if (i < 0) {
		if (errno == ESRCH) {
			delete_finished_bg_job(pi);
			return EXIT_SUCCESS;
		} else {
			bb_perror_msg("kill (SIGCONT)");
		}
	}

	if (*argv[0] == 'f') {
		remove_bg_job(pi);
		return checkjobs_and_fg_shell(pi);
	}
	return EXIT_SUCCESS;
}
#endif

#if ENABLE_HUSH_HELP
static int builtin_help(char **argv UNUSED_PARAM)
{
	const struct built_in_command *x;

	printf("\nBuilt-in commands:\n");
	printf("-------------------\n");
	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
		printf("%s\t%s\n", x->cmd, x->descr);
	}
	printf("\n\n");
	return EXIT_SUCCESS;
}
#endif

#if ENABLE_HUSH_JOB
static int builtin_jobs(char **argv UNUSED_PARAM)
{
	struct pipe *job;
	const char *status_string;

	for (job = job_list; job; job = job->next) {
		if (job->alive_progs == job->stopped_progs)
			status_string = "Stopped";
		else
			status_string = "Running";

		printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
	}
	return EXIT_SUCCESS;
}
#endif

static int builtin_pwd(char **argv UNUSED_PARAM)
{
	puts(set_cwd());
	return EXIT_SUCCESS;
}

static int builtin_read(char **argv)
{
	char *string;
	const char *name = argv[1] ? argv[1] : "REPLY";

	string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
	return set_local_var(string, 0);
}

/* built-in 'set [VAR=value]' handler */
static int builtin_set(char **argv)
{
	char *temp = argv[1];
	struct variable *e;

	if (temp == NULL)
		for (e = top_var; e; e = e->next)
			puts(e->varstr);
	else
		set_local_var(xstrdup(temp), 0);

	return EXIT_SUCCESS;
}

static int builtin_shift(char **argv)
{
	int n = 1;
	if (argv[1]) {
		n = atoi(argv[1]);
	}
	if (n >= 0 && n < global_argc) {
		global_argv[n] = global_argv[0];
		global_argc -= n;
		global_argv += n;
		return EXIT_SUCCESS;
	}
	return EXIT_FAILURE;
}

static int builtin_source(char **argv)
{
	FILE *input;
	int status;

	if (argv[1] == NULL)
		return EXIT_FAILURE;

	/* XXX search through $PATH is missing */
	input = fopen(argv[1], "r");
	if (!input) {
		bb_error_msg("cannot open '%s'", argv[1]);
		return EXIT_FAILURE;
	}
	close_on_exec_on(fileno(input));

	/* Now run the file */
	/* XXX argv and argc are broken; need to save old global_argv
	 * (pointer only is OK!) on this stack frame,
	 * set global_argv=argv+1, recurse, and restore. */
	status = parse_and_run_file(input);
	fclose(input);
	return status;
}

static int builtin_umask(char **argv)
{
	mode_t new_umask;
	const char *arg = argv[1];
	char *end;
	if (arg) {
		new_umask = strtoul(arg, &end, 8);
		if (*end != '\0' || end == arg) {
			return EXIT_FAILURE;
		}
	} else {
		new_umask = umask(0);
		printf("%.3o\n", (unsigned) new_umask);
	}
	umask(new_umask);
	return EXIT_SUCCESS;
}

static int builtin_unset(char **argv)
{
	/* bash always returns true */
	unset_local_var(argv[1]);
	return EXIT_SUCCESS;
}