summaryrefslogtreecommitdiff
path: root/shell/lash.c
blob: f1200ba951f5a530f7d9b9e66f080096d9915494 (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
/* vi: set sw=4 ts=4: */
/*
 * lash -- the BusyBox Lame-Ass SHell
 *
 * Copyright (C) 1999,2000,2001 by Lineo, inc.
 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 *
 * Based in part on ladsh.c by Michael K. Johnson and Erik W. Troan, which is
 * under the following liberal license: "We have placed this source code in the
 * public domain. Use it in any project, free or commercial."
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

/* The parsing engine of this program is officially at a dead-end.
 * Future work in that direction should move to the work posted
 * at http://doolittle.faludi.com/~larry/parser.html .
 * A start on the integration of that work with the rest of sh.c
 * is at http://codepoet.org/sh.c .
 */
//
//This works pretty well now, and is now on by default.
#define BB_FEATURE_SH_ENVIRONMENT
//
//Backtick support has some problems, use at your own risk!
//#define BB_FEATURE_SH_BACKTICKS
//
//If, then, else, etc. support..  This should now behave basically
//like any other Bourne shell -- sortof...
#define BB_FEATURE_SH_IF_EXPRESSIONS
//
/* This is currently sortof broken, only for the brave... */
#undef HANDLE_CONTINUATION_CHARS
//
/* This would be great -- if wordexp wouldn't strip all quoting
 * out from the target strings...  As is, a parser needs  */
#undef BB_FEATURE_SH_WORDEXP
//
//For debugging/development on the shell only...
//#define DEBUG_SHELL


#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <getopt.h>
#include "busybox.h"
#include "cmdedit.h"

#ifdef BB_LOCALE_SUPPORT
#include <locale.h>
#endif

//#define BB_FEATURE_SH_WORDEXP

#ifdef BB_FEATURE_SH_WORDEXP
#include <wordexp.h>
#define expand_t	wordexp_t
#undef BB_FEATURE_SH_BACKTICKS
#else
#include <glob.h>
#define expand_t	glob_t
#endif	


static const int MAX_READ = 128;	/* size of input buffer for `read' builtin */
#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"


enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
	REDIRECT_APPEND
};

static const unsigned int DEFAULT_CONTEXT=0x1;
static const unsigned int IF_TRUE_CONTEXT=0x2;
static const unsigned int IF_FALSE_CONTEXT=0x4;
static const unsigned int THEN_EXP_CONTEXT=0x8;
static const unsigned int ELSE_EXP_CONTEXT=0x10;


struct jobset {
	struct job *head;			/* head of list of running jobs */
	struct job *fg;				/* current foreground job */
};

struct redir_struct {
	enum redir_type type;	/* type of redirection */
	int fd;						/* file descriptor being redirected */
	char *filename;				/* file to redirect fd to */
};

struct child_prog {
	pid_t pid;					/* 0 if exited */
	char **argv;				/* program name and arguments */
	int num_redirects;			/* elements in redirection array */
	struct redir_struct *redirects;	/* I/O redirects */
	int is_stopped;				/* is the program currently running? */
	struct job *family;			/* pointer back to the child's parent job */
};

struct job {
	int jobid;					/* job number */
	int num_progs;				/* total number of programs in job */
	int running_progs;			/* number of programs running */
	char *text;					/* name of job */
	char *cmdbuf;				/* buffer various argv's point into */
	pid_t pgrp;					/* process group ID for the job */
	struct child_prog *progs;	/* array of programs in job */
	struct job *next;			/* to track background commands */
	int stopped_progs;			/* number of programs alive, but stopped */
	unsigned int job_context;	/* bitmask defining current context */
	struct jobset *job_list;
};

struct built_in_command {
	char *cmd;					/* name */
	char *descr;				/* description */
	int (*function) (struct child_prog *);	/* function ptr */
};

struct close_me {
	int fd;
	struct close_me *next;
};

/* function prototypes for builtins */
static int builtin_cd(struct child_prog *cmd);
static int builtin_exec(struct child_prog *cmd);
static int builtin_exit(struct child_prog *cmd);
static int builtin_fg_bg(struct child_prog *cmd);
static int builtin_help(struct child_prog *cmd);
static int builtin_jobs(struct child_prog *dummy);
static int builtin_pwd(struct child_prog *dummy);
static int builtin_export(struct child_prog *cmd);
static int builtin_source(struct child_prog *cmd);
static int builtin_unset(struct child_prog *cmd);
static int builtin_read(struct child_prog *cmd);
#ifdef BB_FEATURE_SH_IF_EXPRESSIONS
static int builtin_if(struct child_prog *cmd);
static int builtin_then(struct child_prog *cmd);
static int builtin_else(struct child_prog *cmd);
static int builtin_fi(struct child_prog *cmd);
/* function prototypes for shell stuff */
static int run_command_predicate(char *cmd);
#endif


/* function prototypes for shell stuff */
static void mark_open(int fd);
static void mark_closed(int fd);
static void close_all(void);
static void checkjobs(struct jobset *job_list);
static int get_command(FILE * source, char *command);
static int parse_command(char **command_ptr, struct job *job, int *inbg);
static int run_command(struct job *newjob, int inbg, int outpipe[2]);
static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn));
static int busy_loop(FILE * input);


/* Table of built-in functions (these are non-forking builtins, meaning they
 * can change global variables in the parent shell process but they will not
 * work with pipes and redirects; 'unset foo | whatever' will not work) */
static struct built_in_command bltins[] = {
	{"bg", "Resume a job in the background", builtin_fg_bg},
	{"cd", "Change working directory", builtin_cd},
	{"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
	{"exit", "Exit from shell()", builtin_exit},
	{"fg", "Bring job into the foreground", builtin_fg_bg},
	{"jobs", "Lists the active jobs", builtin_jobs},
	{"export", "Set environment variable", builtin_export},
	{"unset", "Unset environment variable", builtin_unset},
	{"read", "Input environment variable", builtin_read},
	{".", "Source-in and run commands in a file", builtin_source},
	/* to do: add ulimit */
#ifdef BB_FEATURE_SH_IF_EXPRESSIONS
	{"if", NULL, builtin_if},
	{"then", NULL, builtin_then},
	{"else", NULL, builtin_else},
	{"fi", NULL, builtin_fi},
#endif
	{NULL, NULL, NULL}
};

/* Table of forking built-in functions (things that fork cannot change global
 * variables in the parent process, such as the current working directory) */
static struct built_in_command bltins_forking[] = {
	{"pwd", "Print current directory", builtin_pwd},
	{"help", "List shell built-in commands", builtin_help},
	{NULL, NULL, NULL}
};


/* Variables we export */
unsigned int shell_context;  /* Used in cmdedit.c to reset the
								context when someone hits ^C */


/* Globals that are static to this file */
static const char *cwd;
static char *local_pending_command = NULL;
static struct jobset job_list = { NULL, NULL };
static int argc;
static char **argv;
static struct close_me *close_me_head;
#ifdef BB_FEATURE_SH_ENVIRONMENT
static int last_bg_pid;
static int last_return_code;
static int show_x_trace;
#endif
#ifdef BB_FEATURE_SH_IF_EXPRESSIONS
static char syntax_err[]="syntax error near unexpected token";
#endif

static char *PS1;
static char *PS2 = "> ";


#ifdef DEBUG_SHELL
static inline void debug_printf(const char *format, ...)
{
	va_list args;
	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
}
#else
static inline void debug_printf(const char *format, ...) { }
#endif

/*
	Most builtins need access to the struct child_prog that has
	their arguments, previously coded as cmd->progs[0].  That coding
	can exhibit a bug, if the builtin is not the first command in
	a pipeline: "echo foo | exec sort" will attempt to exec foo.

builtin   previous use      notes
------ -----------------  ---------
cd      cmd->progs[0]
exec    cmd->progs[0]  squashed bug: didn't look for applets or forking builtins
exit    cmd->progs[0]
fg_bg   cmd->progs[0], job_list->head, job_list->fg
help    0
jobs    job_list->head
pwd     0
export  cmd->progs[0]
source  cmd->progs[0]
unset   cmd->progs[0]
read    cmd->progs[0]
if      cmd->job_context,  cmd->text
then    cmd->job_context,  cmd->text
else    cmd->job_context,  cmd->text
fi      cmd->job_context

The use of cmd->text by if/then/else/fi is hopelessly hacky.
Would it work to increment cmd->progs[0]->argv and recurse,
somewhat like builtin_exec does?

I added "struct job *family;" to struct child_prog,
and switched API to builtin_foo(struct child_prog *child);
So   cmd->text        becomes  child->family->text
     cmd->job_context  becomes  child->family->job_context
     cmd->progs[0]    becomes  *child
     job_list          becomes  child->family->job_list
 */

/* built-in 'cd <path>' handler */
static int builtin_cd(struct child_prog *child)
{
	char *newdir;

	if (child->argv[1] == NULL)
		newdir = getenv("HOME");
	else
		newdir = child->argv[1];
	if (chdir(newdir)) {
		printf("cd: %s: %m\n", newdir);
		return EXIT_FAILURE;
	}
	cwd = xgetcwd((char *)cwd);
	if (!cwd)
		cwd = unknown;
	return EXIT_SUCCESS;
}

/* built-in 'exec' handler */
static int builtin_exec(struct child_prog *child)
{
	if (child->argv[1] == NULL)
		return EXIT_SUCCESS;   /* Really? */
	child->argv++;
	close_all();
	pseudo_exec(child);
	/* never returns */
}

/* built-in 'exit' handler */
static int builtin_exit(struct child_prog *child)
{
	if (child->argv[1] == NULL)
		exit(EXIT_SUCCESS);

	exit (atoi(child->argv[1]));
}

/* built-in 'fg' and 'bg' handler */
static int builtin_fg_bg(struct child_prog *child)
{
	int i, jobNum;
	struct job *job=NULL;
	
	if (!child->argv[1] || child->argv[2]) {
		error_msg("%s: exactly one argument is expected",
				child->argv[0]);
		return EXIT_FAILURE;
	}

	if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) {
		error_msg("%s: bad argument '%s'",
				child->argv[0], child->argv[1]);
		return EXIT_FAILURE;
	}

	for (job = child->family->job_list->head; job; job = job->next) {
		if (job->jobid == jobNum) {
			break;
		}
	}

	if (!job) {
		error_msg("%s: unknown job %d",
				child->argv[0], jobNum);
		return EXIT_FAILURE;
	}

	if (*child->argv[0] == 'f') {
		/* Make this job the foreground job */
		/* suppress messages when run from /linuxrc mag@sysgo.de */
		if (tcsetpgrp(0, job->pgrp) && errno != ENOTTY)
			perror_msg("tcsetpgrp"); 
		child->family->job_list->fg = job;
	}

	/* Restart the processes in the job */
	for (i = 0; i < job->num_progs; i++)
		job->progs[i].is_stopped = 0;

	kill(-job->pgrp, SIGCONT);

	job->stopped_progs = 0;

	return EXIT_SUCCESS;
}

/* built-in 'help' handler */
static int builtin_help(struct child_prog *dummy)
{
	struct built_in_command *x;

	printf("\nBuilt-in commands:\n");
	printf("-------------------\n");
	for (x = bltins; x->cmd; x++) {
		if (x->descr==NULL)
			continue;
		printf("%s\t%s\n", x->cmd, x->descr);
	}
	for (x = bltins_forking; x->cmd; x++) {
		if (x->descr==NULL)
			continue;
		printf("%s\t%s\n", x->cmd, x->descr);
	}
	printf("\n\n");
	return EXIT_SUCCESS;
}

/* built-in 'jobs' handler */
static int builtin_jobs(struct child_prog *child)
{
	struct job *job;
	char *status_string;

	for (job = child->family->job_list->head; job; job = job->next) {
		if (job->running_progs == job->stopped_progs)
			status_string = "Stopped";
		else
			status_string = "Running";

		printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
	}
	return EXIT_SUCCESS;
}


/* built-in 'pwd' handler */
static int builtin_pwd(struct child_prog *dummy)
{
	cwd = xgetcwd((char *)cwd);
	if (!cwd)
		cwd = unknown;
	puts(cwd);
	return EXIT_SUCCESS;
}

/* built-in 'export VAR=value' handler */
static int builtin_export(struct child_prog *child)
{
	int res;
	char *v = child->argv[1];

	if (v == NULL) {
		char **e;
		for (e = environ; *e; e++) {
			puts(*e);
		}
		return 0;
	}
	res = putenv(v);
	if (res)
		fprintf(stderr, "export: %m\n");
#ifdef BB_FEATURE_SH_FANCY_PROMPT
	if (strncmp(v, "PS1=", 4)==0)
		PS1 = getenv("PS1");
#endif

#ifdef BB_LOCALE_SUPPORT
	if(strncmp(v, "LC_ALL=", 7)==0)
		setlocale(LC_ALL, getenv("LC_ALL"));
	if(strncmp(v, "LC_CTYPE=", 9)==0)
		setlocale(LC_CTYPE, getenv("LC_CTYPE"));
#endif

	return (res);
}

/* built-in 'read VAR' handler */
static int builtin_read(struct child_prog *child)
{
	int res = 0, len, newlen;
	char *s;
	char string[MAX_READ];

	if (child->argv[1]) {
		/* argument (VAR) given: put "VAR=" into buffer */
		strcpy(string, child->argv[1]);
		len = strlen(string);
		string[len++] = '=';
		string[len]   = '\0';
		fgets(&string[len], sizeof(string) - len, stdin);	/* read string */
		newlen = strlen(string);
		if(newlen > len)
			string[--newlen] = '\0';	/* chomp trailing newline */
		/*
		** string should now contain "VAR=<value>"
		** copy it (putenv() won't do that, so we must make sure
		** the string resides in a static buffer!)
		*/
		res = -1;
		if((s = strdup(string)))
			res = putenv(s);
		if (res)
			fprintf(stderr, "read: %m\n");
	}
	else
		fgets(string, sizeof(string), stdin);

	return (res);
}

#ifdef BB_FEATURE_SH_IF_EXPRESSIONS
/* Built-in handler for 'if' commands */
static int builtin_if(struct child_prog *child)
{
	struct job *cmd = child->family;
	int status;
	char* charptr1=cmd->text+3; /* skip over the leading 'if ' */

	/* Now run the 'if' command */
	debug_printf( "job=%p entering builtin_if ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
	status = run_command_predicate(charptr1);
	debug_printf( "if test returned ");
	if (status == 0) {
		debug_printf( "TRUE\n");
		cmd->job_context |= IF_TRUE_CONTEXT;
	} else {
		debug_printf( "FALSE\n");
		cmd->job_context |= IF_FALSE_CONTEXT;
	}
	debug_printf("job=%p builtin_if set job context to %x\n", cmd, cmd->job_context);
	shell_context++;

	return status;
}

/* Built-in handler for 'then' (part of the 'if' command) */
static int builtin_then(struct child_prog *child)
{
	struct job *cmd = child->family;
	char* charptr1=cmd->text+5; /* skip over the leading 'then ' */

	debug_printf( "job=%p entering builtin_then ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
	if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
		shell_context = 0; /* Reset the shell's context on an error */
		error_msg("%s `then'", syntax_err);
		return EXIT_FAILURE;
	}

	cmd->job_context |= THEN_EXP_CONTEXT;
	debug_printf("job=%p builtin_then set job context to %x\n", cmd, cmd->job_context);

	/* If the if result was FALSE, skip the 'then' stuff */
	if (cmd->job_context & IF_FALSE_CONTEXT) {
		return EXIT_SUCCESS;
	}

	/* Seems the if result was TRUE, so run the 'then' command */
	debug_printf( "'then' now running '%s'\n", charptr1);

	return(run_command_predicate(charptr1));
}

/* Built-in handler for 'else' (part of the 'if' command) */
static int builtin_else(struct child_prog *child)
{
	struct job *cmd = child->family;
	char* charptr1=cmd->text+5; /* skip over the leading 'else ' */

	debug_printf( "job=%p entering builtin_else ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);

	if (! (cmd->job_context & THEN_EXP_CONTEXT)) {
		shell_context = 0; /* Reset the shell's context on an error */
		error_msg("%s `else'", syntax_err);
		return EXIT_FAILURE;
	}
	/* If the if result was TRUE, skip the 'else' stuff */
	if (cmd->job_context & IF_TRUE_CONTEXT) {
		return EXIT_SUCCESS;
	}

	cmd->job_context |= ELSE_EXP_CONTEXT;
	debug_printf("job=%p builtin_else set job context to %x\n", cmd, cmd->job_context);

	/* Now run the 'else' command */
	debug_printf( "'else' now running '%s'\n", charptr1);
	return(run_command_predicate(charptr1));
}

/* Built-in handler for 'fi' (part of the 'if' command) */
static int builtin_fi(struct child_prog *child)
{
	struct job *cmd = child->family;
	debug_printf( "job=%p entering builtin_fi ('%s')-- context=%d\n", cmd, "", cmd->job_context);
	if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
		shell_context = 0; /* Reset the shell's context on an error */
		error_msg("%s `fi'", syntax_err);
		return EXIT_FAILURE;
	}
	/* Clear out the if and then context bits */
	cmd->job_context &= ~(IF_TRUE_CONTEXT|IF_FALSE_CONTEXT|THEN_EXP_CONTEXT|ELSE_EXP_CONTEXT);
	debug_printf("job=%p builtin_fi set job context to %x\n", cmd, cmd->job_context);
	shell_context--;
	return EXIT_SUCCESS;
}
#endif

/* Built-in '.' handler (read-in and execute commands from file) */
static int builtin_source(struct child_prog *child)
{
	FILE *input;
	int status;
	int fd;

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

	input = fopen(child->argv[1], "r");
	if (!input) {
		printf( "Couldn't open file '%s'\n", child->argv[1]);
		return EXIT_FAILURE;
	}

	fd=fileno(input);
	mark_open(fd);
	/* Now run the file */
	status = busy_loop(input);
	fclose(input);
	mark_closed(fd);
	return (status);
}

/* built-in 'unset VAR' handler */
static int builtin_unset(struct child_prog *child)
{
	if (child->argv[1] == NULL) {
		printf( "unset: parameter required.\n");
		return EXIT_FAILURE;
	}
	unsetenv(child->argv[1]);
	return EXIT_SUCCESS;
}

#ifdef BB_FEATURE_SH_IF_EXPRESSIONS
/* currently used by if/then/else.
 *
 * Reparsing the command line for this purpose is gross,
 * incorrect, and fundamentally unfixable; in particular,
 * think about what happens with command substitution.
 * We really need to pull out the run, wait, return status
 * functionality out of busy_loop so we can child->argv++
 * and use that, without going back through parse_command.
 */
static int run_command_predicate(char *cmd)
{
	local_pending_command = xstrdup(cmd);
	return( busy_loop(NULL));
}
#endif

static void mark_open(int fd)
{
	struct close_me *new = xmalloc(sizeof(struct close_me));
	new->fd = fd;
	new->next = close_me_head;
	close_me_head = new;
}

static void mark_closed(int fd)
{
	struct close_me *tmp;
	if (close_me_head == NULL || close_me_head->fd != fd)
		error_msg_and_die("corrupt close_me");
	tmp = close_me_head;
	close_me_head = close_me_head->next;
	free(tmp);
}

static void close_all()
{
	struct close_me *c, *tmp;
	for (c=close_me_head; c; c=tmp) {
		close(c->fd);
		tmp=c->next;
		free(c);
	}
	close_me_head = NULL;
}


/* free up all memory from a job */
static void free_job(struct job *cmd)
{
	int i;
	struct jobset *keep;

	for (i = 0; i < cmd->num_progs; i++) {
		free(cmd->progs[i].argv);
		if (cmd->progs[i].redirects)
			free(cmd->progs[i].redirects);
	}
	if (cmd->progs)
		free(cmd->progs);
	if (cmd->text)
		free(cmd->text);
	if (cmd->cmdbuf)
		free(cmd->cmdbuf);
	keep = cmd->job_list;
	memset(cmd, 0, sizeof(struct job));
	cmd->job_list = keep;
}

/* remove a job from a jobset */
static void remove_job(struct jobset *j_list, struct job *job)
{
	struct job *prevjob;

	free_job(job);
	if (job == j_list->head) {
		j_list->head = job->next;
	} else {
		prevjob = j_list->head;
		while (prevjob->next != job)
			prevjob = prevjob->next;
		prevjob->next = job->next;
	}

	free(job);
}

/* Checks to see if any background processes have exited -- if they 
   have, figure out why and see if a job has completed */
static void checkjobs(struct jobset *j_list)
{
	struct job *job;
	pid_t childpid;
	int status;
	int prognum = 0;

	while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
		for (job = j_list->head; job; job = job->next) {
			prognum = 0;
			while (prognum < job->num_progs &&
				   job->progs[prognum].pid != childpid) prognum++;
			if (prognum < job->num_progs)
				break;
		}

		/* This happens on backticked commands */
		if(job==NULL)
			return;

		if (WIFEXITED(status) || WIFSIGNALED(status)) {
			/* child exited */
			job->running_progs--;
			job->progs[prognum].pid = 0;

			if (!job->running_progs) {
				printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
				remove_job(j_list, job);
			}
		} else {
			/* child stopped */
			job->stopped_progs++;
			job->progs[prognum].is_stopped = 1;

			if (job->stopped_progs == job->num_progs) {
				printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
					   job->text);
			}
		}
	}

	if (childpid == -1 && errno != ECHILD)
		perror_msg("waitpid");
}

/* 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 i;
	int openfd;
	int mode = O_RDONLY;
	struct redir_struct *redir = prog->redirects;

	for (i = 0; i < prog->num_redirects; i++, redir++) {
		switch (redir->type) {
		case REDIRECT_INPUT:
			mode = O_RDONLY;
			break;
		case REDIRECT_OVERWRITE:
			mode = O_WRONLY | O_CREAT | O_TRUNC;
			break;
		case REDIRECT_APPEND:
			mode = O_WRONLY | O_CREAT | O_APPEND;
			break;
		}

		openfd = open(redir->filename, mode, 0666);
		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!) */
			perror_msg("error opening %s", redir->filename);
			return 1;
		}

		if (openfd != redir->fd) {
			if (squirrel && redir->fd < 3) {
				squirrel[redir->fd] = dup(redir->fd);
			}
			dup2(openfd, redir->fd);
			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) {
			/* No error checking.  I sure wouldn't know what
			 * to do with an error if I found one! */
			dup2(fd, i);
			close(fd);
		}
	}
}

static inline void cmdedit_set_initial_prompt(void)
{
#ifndef BB_FEATURE_SH_FANCY_PROMPT
	PS1 = NULL;
#else
	PS1 = getenv("PS1");
	if(PS1==0)
		PS1 = "\\w \\$ ";
#endif	
}

static inline void setup_prompt_string(char **prompt_str)
{
#ifndef BB_FEATURE_SH_FANCY_PROMPT
	/* Set up the prompt */
	if (shell_context == 0) {
		if (PS1)
			free(PS1);
		PS1=xmalloc(strlen(cwd)+4);
		sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
		*prompt_str = PS1;
	} else {
		*prompt_str = PS2;
	}
#else
	*prompt_str = (shell_context==0)? PS1 : PS2;
#endif	
}

static int get_command(FILE * source, char *command)
{
	char *prompt_str;

	if (source == NULL) {
		if (local_pending_command) {
			/* a command specified (-c option): return it & mark it done */
			strcpy(command, local_pending_command);
			free(local_pending_command);
			local_pending_command = NULL;
			return 0;
		}
		return 1;
	}

	if (source == stdin) {
		setup_prompt_string(&prompt_str);

#ifdef BB_FEATURE_COMMAND_EDITING
		/*
		** enable command line editing only while a command line
		** is actually being read; otherwise, we'll end up bequeathing
		** atexit() handlers and other unwanted stuff to our
		** child processes (rob@sysgo.de)
		*/
		cmdedit_read_input(prompt_str, command);
		cmdedit_terminate();
		return 0;
#else
		fputs(prompt_str, stdout);
#endif
	}

	if (!fgets(command, BUFSIZ - 2, source)) {
		if (source == stdin)
			printf("\n");
		return 1;
	}

	return 0;
}

#ifdef BB_FEATURE_SH_ENVIRONMENT
static char* itoa(register int i)
{
	static char a[7]; /* Max 7 ints */
	register char *b = a + sizeof(a) - 1;
	int   sign = (i < 0);

	if (sign)
		i = -i;
	*b = 0;
	do
	{
		*--b = '0' + (i % 10);
		i /= 10;
	}
	while (i);
	if (sign)
		*--b = '-';
	return b;
}
#endif	

#if defined BB_FEATURE_SH_ENVIRONMENT && ! defined BB_FEATURE_SH_WORDEXP
char * strsep_space( char *string, int * ix)
{
	char *token, *begin;

	begin = string;

	/* Short circuit the trivial case */
	if ( !string || ! string[*ix])
		return NULL;

	/* Find the end of the token. */
	while( string && string[*ix] && !isspace(string[*ix]) ) {
		(*ix)++;
	}

	/* Find the end of any whitespace trailing behind 
	 * the token and let that be part of the token */
	while( string && string[*ix] && isspace(string[*ix]) ) {
		(*ix)++;
	}

	if (! string && *ix==0) {
		/* Nothing useful was found */
		return NULL;
	}

	token = xmalloc(*ix+1);
	token[*ix] = '\0';
	strncpy(token, string,  *ix); 

	return token;
}
#endif	


static int expand_arguments(char *command)
{
#ifdef BB_FEATURE_SH_ENVIRONMENT
	expand_t expand_result;
	char *src, *dst, *var;
	int ix = 0;
	int i=0, length, total_length=0, retval;
	const char *out_of_space = "out of space during expansion"; 
#endif

	/* get rid of the terminating \n */
	chomp(command);
	
	/* Fix up escape sequences to be the Real Thing(tm) */
	while( command && command[ix]) {
		if (command[ix] == '\\') {
			const char *tmp = command+ix+1;
			command[ix] = process_escape_sequence(  &tmp );
			memmove(command+ix + 1, tmp, strlen(tmp)+1);
		}
		ix++;
	}

#ifdef BB_FEATURE_SH_ENVIRONMENT


#ifdef BB_FEATURE_SH_WORDEXP
	/* This first part uses wordexp() which is a wonderful C lib 
	 * function which expands nearly everything.  */ 
	retval = wordexp (command, &expand_result, WRDE_SHOWERR);
	if (retval == WRDE_NOSPACE) {
		/* Mem may have been allocated... */
		wordfree (&expand_result);
		error_msg(out_of_space);
		return FALSE;
	}
	if (retval < 0) {
		/* Some other error.  */
		error_msg("syntax error");
		return FALSE;
	}
	
	if (expand_result.we_wordc > 0) {
		/* Convert from char** (one word per string) to a simple char*,
		 * but don't overflow command which is BUFSIZ in length */
		*command = '\0';
		while (i < expand_result.we_wordc && total_length < BUFSIZ) {
			length=strlen(expand_result.we_wordv[i])+1;
			if (BUFSIZ-total_length-length <= 0) {
				error_msg(out_of_space);
				return FALSE;
			}
			strcat(command+total_length, expand_result.we_wordv[i++]);
			strcat(command+total_length, " ");
			total_length+=length;
		}
		wordfree (&expand_result);
	}
#else

	/* Ok.  They don't have a recent glibc and they don't have uClibc.  Chances
	 * are about 100% they don't have wordexp(). So instead the best we can do
	 * is use glob and then fixup environment variables and such ourselves.
	 * This is better then nothing, but certainly not perfect */

	/* It turns out that glob is very stupid.  We have to feed it one word at a
	 * time since it can't cope with a full string.  Here we convert command
	 * (char*) into cmd (char**, one word per string) */
	{
        
		int flags = GLOB_NOCHECK
#ifdef GLOB_BRACE
				| GLOB_BRACE
#endif	
#ifdef GLOB_TILDE
				| GLOB_TILDE
#endif	
			;
		char *tmpcmd, *cmd, *cmd_copy;
		/* We need a clean copy, so strsep can mess up the copy while
		 * we write stuff into the original (in a minute) */
		cmd = cmd_copy = strdup(command);
		*command = '\0';
		for (ix = 0, tmpcmd = cmd; 
				(tmpcmd = strsep_space(cmd, &ix)) != NULL; cmd += ix, ix=0) {
			if (*tmpcmd == '\0')
				break;
			/* we need to trim() the result for glob! */
			trim(tmpcmd);
			retval = glob(tmpcmd, flags, NULL, &expand_result);
			free(tmpcmd); /* Free mem allocated by strsep_space */
			if (retval == GLOB_NOSPACE) {
				/* Mem may have been allocated... */
				globfree (&expand_result);
				error_msg(out_of_space);
				return FALSE;
			} else if (retval != 0) {
				/* Some other error.  GLOB_NOMATCH shouldn't
				 * happen because of the GLOB_NOCHECK flag in 
				 * the glob call. */
				error_msg("syntax error");
				return FALSE;
			} else {
			/* Convert from char** (one word per string) to a simple char*,
			 * but don't overflow command which is BUFSIZ in length */
				for (i=0; i < expand_result.gl_pathc; i++) {
					length=strlen(expand_result.gl_pathv[i]);
					if (total_length+length+1 >= BUFSIZ) {
						error_msg(out_of_space);
						return FALSE;
					}
					strcat(command+total_length, " ");
					total_length+=1;
					strcat(command+total_length, expand_result.gl_pathv[i]);
					total_length+=length;
				}
				globfree (&expand_result);
			}
		}
		free(cmd_copy);
		trim(command);
	}
	
#endif	

	/* Now do the shell variable substitutions which 
	 * wordexp can't do for us, namely $? and $! */
	src = command;
	while((dst = strchr(src,'$')) != NULL){
		var = NULL;
		switch(*(dst+1)) {
			case '?':
				var = itoa(last_return_code);
				break;
			case '!':
				if (last_bg_pid==-1)
					*(var)='\0';
				else
					var = itoa(last_bg_pid);
				break;
				/* Everything else like $$, $#, $[0-9], etc should all be
				 * expanded by wordexp(), so we can in theory skip that stuff
				 * here, but just to be on the safe side (i.e. since uClibc
				 * wordexp doesn't do this stuff yet), lets leave it in for
				 * now. */
			case '$':
				var = itoa(getpid());
				break;
			case '#':
				var = itoa(argc-1);
				break;
			case '0':case '1':case '2':case '3':case '4':
			case '5':case '6':case '7':case '8':case '9':
				{
					int ixx=*(dst + 1)-48;
					if (ixx >= argc) {
						var='\0';
					} else {
						var = argv[ixx];
					}
				}
				break;

		}
		if (var) {
			/* a single character construction was found, and 
			 * already handled in the case statement */
			src=dst+2;
		} else {
			/* Looks like an environment variable */
			char delim_hold;
			int num_skip_chars=0;
			int dstlen = strlen(dst);
			/* Is this a ${foo} type variable? */
			if (dstlen >=2 && *(dst+1) == '{') {
				src=strchr(dst+1, '}');
				num_skip_chars=1;
			} else {
				src=dst+1;
				while(isalnum(*src) || *src=='_') src++;
			}
			if (src == NULL) {
				src = dst+dstlen;
			}
			delim_hold=*src;
			*src='\0';  /* temporary */
			var = getenv(dst + 1 + num_skip_chars);
			*src=delim_hold;
			src += num_skip_chars;
		}
		if (var == NULL) {
			/* Seems we got an un-expandable variable.  So delete it. */
			var = "";
		}
		{
			int subst_len = strlen(var);
			int trail_len = strlen(src);
			if (dst+subst_len+trail_len >= command+BUFSIZ) {
				error_msg(out_of_space);
				return FALSE;
			}
			/* Move stuff to the end of the string to accommodate
			 * filling the created gap with the new stuff */
			memmove(dst+subst_len, src, trail_len+1);
			/* Now copy in the new stuff */
			memcpy(dst, var, subst_len);
			src = dst+subst_len;
		}
	}

#endif	
	return TRUE;
}

/* Return cmd->num_progs as 0 if no command is present (e.g. an empty
   line). If a valid command is found, command_ptr is set to point to
   the beginning of the next command (if the original command had more 
   then one job associated with it) or NULL if no more commands are 
   present. */
static int parse_command(char **command_ptr, struct job *job, int *inbg)
{
	char *command;
	char *return_command = NULL;
	char *src, *buf, *chptr;
	int argc_l = 0;
	int done = 0;
	int argv_alloced;
	int i, saw_quote = 0;
	char quote = '\0';
	int count;
	struct child_prog *prog;

	/* skip leading white space */
	while (**command_ptr && isspace(**command_ptr))
		(*command_ptr)++;

	/* this handles empty lines or leading '#' characters */
	if (!**command_ptr || (**command_ptr == '#')) {
		job->num_progs=0;
		return 0;
	}

	*inbg = 0;
	job->num_progs = 1;
	job->progs = xmalloc(sizeof(*job->progs));

	/* We set the argv elements to point inside of this string. The 
	   memory is freed by free_job(). Allocate twice the original
	   length in case we need to quote every single character.

	   Getting clean memory relieves us of the task of NULL 
	   terminating things and makes the rest of this look a bit 
	   cleaner (though it is, admittedly, a tad less efficient) */
	job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
	job->text = NULL;

	prog = job->progs;
	prog->num_redirects = 0;
	prog->redirects = NULL;
	prog->is_stopped = 0;
	prog->family = job;

	argv_alloced = 5;
	prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
	prog->argv[0] = job->cmdbuf;

	buf = command;
	src = *command_ptr;
	while (*src && !done) {
		if (quote == *src) {
			quote = '\0';
		} else if (quote) {
			if (*src == '\\') {
				src++;
				if (!*src) {
					error_msg("character expected after \\");
					free_job(job);
					return 1;
				}

				/* in shell, "\'" should yield \' */
				if (*src != quote) {
					*buf++ = '\\';
					*buf++ = '\\';
				}
			} else if (*src == '*' || *src == '?' || *src == '[' ||
					   *src == ']') *buf++ = '\\';
			*buf++ = *src;
		} else if (isspace(*src)) {
			if (*prog->argv[argc_l] || saw_quote) {
				buf++, argc_l++;
				/* +1 here leaves room for the NULL which ends argv */
				if ((argc_l + 1) == argv_alloced) {
					argv_alloced += 5;
					prog->argv = xrealloc(prog->argv,
										  sizeof(*prog->argv) *
										  argv_alloced);
				}
				prog->argv[argc_l] = buf;
				saw_quote = 0;
			}
		} else
			switch (*src) {
			case '"':
			case '\'':
				quote = *src;
				saw_quote = 1;
				break;

			case '#':			/* comment */
				if (*(src-1)== '$')
					*buf++ = *src;
				else
					done = 1;
				break;

			case '>':			/* redirects */
			case '<':
				i = prog->num_redirects++;
				prog->redirects = xrealloc(prog->redirects,
											  sizeof(*prog->redirects) *
											  (i + 1));

				prog->redirects[i].fd = -1;
				if (buf != prog->argv[argc_l]) {
					/* the stuff before this character may be the file number 
					   being redirected */
					prog->redirects[i].fd =
						strtol(prog->argv[argc_l], &chptr, 10);

					if (*chptr && *prog->argv[argc_l]) {
						buf++, argc_l++;
						prog->argv[argc_l] = buf;
					}
				}

				if (prog->redirects[i].fd == -1) {
					if (*src == '>')
						prog->redirects[i].fd = 1;
					else
						prog->redirects[i].fd = 0;
				}

				if (*src++ == '>') {
					if (*src == '>')
						prog->redirects[i].type =
							REDIRECT_APPEND, src++;
					else
						prog->redirects[i].type = REDIRECT_OVERWRITE;
				} else {
					prog->redirects[i].type = REDIRECT_INPUT;
				}

				/* This isn't POSIX sh compliant. Oh well. */
				chptr = src;
				while (isspace(*chptr))
					chptr++;

				if (!*chptr) {
					error_msg("file name expected after %c", *(src-1));
					free_job(job);
					job->num_progs=0;
					return 1;
				}

				prog->redirects[i].filename = buf;
				while (*chptr && !isspace(*chptr))
					*buf++ = *chptr++;

				src = chptr - 1;	/* we src++ later */
				prog->argv[argc_l] = ++buf;
				break;

			case '|':			/* pipe */
				/* finish this command */
				if (*prog->argv[argc_l] || saw_quote)
					argc_l++;
				if (!argc_l) {
					error_msg("empty command in pipe");
					free_job(job);
					job->num_progs=0;
					return 1;
				}
				prog->argv[argc_l] = NULL;

				/* and start the next */
				job->num_progs++;
				job->progs = xrealloc(job->progs,
									  sizeof(*job->progs) * job->num_progs);
				prog = job->progs + (job->num_progs - 1);
				prog->num_redirects = 0;
				prog->redirects = NULL;
				prog->is_stopped = 0;
				prog->family = job;
				argc_l = 0;

				argv_alloced = 5;
				prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
				prog->argv[0] = ++buf;

				src++;
				while (*src && isspace(*src))
					src++;

				if (!*src) {
					error_msg("empty command in pipe");
					free_job(job);
					job->num_progs=0;
					return 1;
				}
				src--;			/* we'll ++ it at the end of the loop */

				break;

			case '&':			/* background */
				*inbg = 1;
			case ';':			/* multiple commands */
				done = 1;
				return_command = *command_ptr + (src - *command_ptr) + 1;
				break;

#ifdef BB_FEATURE_SH_BACKTICKS
			case '`':
				/* Exec a backtick-ed command */
				/* Besides any previous brokenness, I have not
				 * updated backtick handling for close_me support.
				 * I don't know if it needs it or not.  -- LRD */
				{
					char* charptr1=NULL, *charptr2;
					char* ptr=NULL;
					struct job *newjob;
					struct jobset njob_list = { NULL, NULL };
					int pipefd[2];
					int size;

					ptr=strchr(++src, '`');
					if (ptr==NULL) {
						fprintf(stderr, "Unmatched '`' in command\n");
						free_job(job);
						return 1;
					}

					/* Make some space to hold just the backticked command */
					charptr1 = charptr2 = xmalloc(1+ptr-src);
					memcpy(charptr1, src, ptr-src);
					charptr1[ptr-src] = '\0';
					newjob = xmalloc(sizeof(struct job));
					newjob->job_list = &njob_list;
					/* Now parse and run the backticked command */
					if (!parse_command(&charptr1, newjob, inbg) 
							&& newjob->num_progs) {
						pipe(pipefd);
						run_command(newjob, 0, pipefd);
					}
					checkjobs(job->job_list);
					free_job(newjob);  /* doesn't actually free newjob,
					                     looks like a memory leak */
					free(charptr2);
					
					/* Make a copy of any stuff left over in the command 
					 * line after the second backtick */
					charptr2 = xmalloc(strlen(ptr)+1);
					memcpy(charptr2, ptr+1, strlen(ptr));


					/* Copy the output from the backtick-ed command into the
					 * command line, making extra room as needed  */
					--src;
					charptr1 = xmalloc(BUFSIZ);
					while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
						int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
						if (newsize > BUFSIZ) {
							*command_ptr=xrealloc(*command_ptr, newsize);
						}
						memcpy(src, charptr1, size); 
						src+=size;
					}
					free(charptr1);
					close(pipefd[0]);
					if (*(src-1)=='\n')
						--src;

					/* Now paste into the *command_ptr all the stuff 
					 * leftover after the second backtick */
					memcpy(src, charptr2, strlen(charptr2)+1);
					free(charptr2);

					/* Now recursively call parse_command to deal with the new
					 * and improved version of the command line with the backtick
					 * results expanded in place... */
					{
						struct jobset *jl=job->job_list;
						free_job(job);
						job->job_list = jl;
					}
					return(parse_command(command_ptr, job, inbg));
				}
				break;
#endif // BB_FEATURE_SH_BACKTICKS

			case '\\':
				src++;
				if (!*src) {
/* This is currently a little broken... */
#ifdef HANDLE_CONTINUATION_CHARS
					/* They fed us a continuation char, so continue reading stuff
					 * on the next line, then tack that onto the end of the current
					 * command */
					char *command;
					int newsize;
					printf("erik: found a continue char at EOL...\n");
					command = (char *) xcalloc(BUFSIZ, sizeof(char));
					if (get_command(input, command)) {
						error_msg("character expected after \\");
						free(command);
						free_job(job);
						return 1;
					}
					newsize = strlen(*command_ptr) + strlen(command) + 2;
					if (newsize > BUFSIZ) {
						printf("erik: doing realloc\n");
						*command_ptr=xrealloc(*command_ptr, newsize);
					}
					printf("erik: A: *command_ptr='%s'\n", *command_ptr);
					memcpy(--src, command, strlen(command)); 
					printf("erik: B: *command_ptr='%s'\n", *command_ptr);
					free(command);
					break;
#else
					error_msg("character expected after \\");
					free_job(job);
					return 1;
#endif
				}
				if (*src == '*' || *src == '[' || *src == ']'
					|| *src == '?') *buf++ = '\\';
				/* fallthrough */
			default:
				*buf++ = *src;
			}

		src++;
	}

	if (*prog->argv[argc_l] || saw_quote) {
		argc_l++;
	}
	if (!argc_l) {
		free_job(job);
		return 0;
	}
	prog->argv[argc_l] = NULL;

	if (!return_command) {
		job->text = xmalloc(strlen(*command_ptr) + 1);
		strcpy(job->text, *command_ptr);
	} else {
		/* This leaves any trailing spaces, which is a bit sloppy */
		count = return_command - *command_ptr;
		job->text = xmalloc(count + 1);
		strncpy(job->text, *command_ptr, count);
		job->text[count] = '\0';
	}

	*command_ptr = return_command;
	
	return 0;
}

/* Run the child_prog, no matter what kind of command it uses.
 */
static int pseudo_exec(struct child_prog *child)
{
	struct built_in_command *x;
#ifdef BB_FEATURE_SH_STANDALONE_SHELL
	char *name;
#endif

	/* Check if the command matches any of the non-forking 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->cmd; x++) {
		if (strcmp(child->argv[0], x->cmd) == 0 ) {
			exit(x->function(child));
		}
	}

	/* Check if the command matches any of the forking builtins. */
	for (x = bltins_forking; x->cmd; x++) {
		if (strcmp(child->argv[0], x->cmd) == 0) {
			applet_name=x->cmd;
			exit (x->function(child));
		}
	}
#ifdef BB_FEATURE_SH_STANDALONE_SHELL
	/* Check if the command matches any busybox internal
	 * commands ("applets") here.  Following discussions from
	 * November 2000 on busybox@opensource.lineo.com, don't use
	 * get_last_path_component().  This way explicit (with
	 * slashes) filenames will never be interpreted as an
	 * applet, just like with builtins.  This way the user can
	 * override an applet with an explicit filename reference.
	 * The only downside to this change is that an explicit
	 * /bin/foo invocation will fork and exec /bin/foo, even if
	 * /bin/foo is a symlink to busybox.
	 */
	name = child->argv[0];

#ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
	/* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
	 * if you run /bin/cat, it will use BusyBox cat even if 
	 * /bin/cat exists on the filesystem and is _not_ busybox.
	 * Some systems want this, others do not.  Choose wisely.  :-)
	 */
	name = get_last_path_component(name);
#endif

	{
	    char** argv_l=child->argv;
	    int argc_l;
	    for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
	    optind = 1;
	    run_applet_by_name(name, argc_l, child->argv);
	}
#endif

	execvp(child->argv[0], child->argv);
	perror_msg_and_die("%s", child->argv[0]);
}

static void insert_job(struct job *newjob, int inbg)
{
	struct job *thejob;
	struct jobset *j_list=newjob->job_list;

	/* find the ID for thejob to use */
	newjob->jobid = 1;
	for (thejob = j_list->head; thejob; thejob = thejob->next)
		if (thejob->jobid >= newjob->jobid)
			newjob->jobid = thejob->jobid + 1;

	/* add thejob to the list of running jobs */
	if (!j_list->head) {
		thejob = j_list->head = xmalloc(sizeof(*thejob));
	} else {
		for (thejob = j_list->head; thejob->next; thejob = thejob->next) /* nothing */;
		thejob->next = xmalloc(sizeof(*thejob));
		thejob = thejob->next;
	}

	*thejob = *newjob;   /* physically copy the struct job */
	thejob->next = NULL;
	thejob->running_progs = thejob->num_progs;
	thejob->stopped_progs = 0;

	if (inbg) {
		/* we don't wait for background thejobs to return -- append it 
		   to the list of backgrounded thejobs and leave it alone */
		printf("[%d] %d\n", thejob->jobid,
			   newjob->progs[newjob->num_progs - 1].pid);
#ifdef BB_FEATURE_SH_ENVIRONMENT
		last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
#endif
	} else {
		newjob->job_list->fg = thejob;

		/* move the new process group into the foreground */
		/* suppress messages when run from /linuxrc mag@sysgo.de */
		if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
			perror_msg("tcsetpgrp");
	}
}

static int run_command(struct job *newjob, int inbg, int outpipe[2])
{
	/* struct job *thejob; */
	int i;
	int nextin, nextout;
	int pipefds[2];				/* pipefd[0] is for reading */
	struct built_in_command *x;
	struct child_prog *child;

	nextin = 0, nextout = 1;
	for (i = 0; i < newjob->num_progs; i++) {
		child = & (newjob->progs[i]);

		if ((i + 1) < newjob->num_progs) {
			if (pipe(pipefds)<0) perror_msg_and_die("pipe");
			nextout = pipefds[1];
		} else {
			if (outpipe[1]!=-1) {
				nextout = outpipe[1];
			} else {
				nextout = 1;
			}
		}

#ifdef BB_FEATURE_SH_ENVIRONMENT
		if (show_x_trace==TRUE) {
			int j;
			fputc('+', stderr);
			for (j = 0; child->argv[j]; j++) {
				fputc(' ', stderr);
				fputs(child->argv[j], stderr);
			}
			fputc('\n', stderr);
		}
#endif

		/* Check if the command matches any non-forking builtins,
		 * but only if this is a simple command.
		 * Non-forking builtins within pipes have to fork anyway,
		 * and are handled in pseudo_exec.  "echo foo | read bar"
		 * is doomed to failure, and doesn't work on bash, either.
		 */
		if (newjob->num_progs == 1) {
			for (x = bltins; x->cmd; x++) {
				if (strcmp(child->argv[0], x->cmd) == 0 ) {
					int squirrel[] = {-1, -1, -1};
					int rcode;
					setup_redirects(child, squirrel);
					rcode = x->function(child);
					restore_redirects(squirrel);
					return rcode;
				}
			}
		}

		if (!(child->pid = fork())) {
			signal(SIGTTOU, SIG_DFL);

			close_all();

			if (outpipe[1]!=-1) {
				close(outpipe[0]);
			}
			if (nextin != 0) {
				dup2(nextin, 0);
				close(nextin);
			}

			if (nextout != 1) {
				dup2(nextout, 1);
				dup2(nextout, 2);  /* Really? */
				close(nextout);
				close(pipefds[0]);
			}

			/* explicit redirects override pipes */
			setup_redirects(child,NULL);

			pseudo_exec(child);
		}
		if (outpipe[1]!=-1) {
			close(outpipe[1]);
		}

		/* put our child in the process group whose leader is the
		   first process in this pipe */
		setpgid(child->pid, newjob->progs[0].pid);
		if (nextin != 0)
			close(nextin);
		if (nextout != 1)
			close(nextout);

		/* If there isn't another process, nextin is garbage 
		   but it doesn't matter */
		nextin = pipefds[0];
	}

	newjob->pgrp = newjob->progs[0].pid;

	insert_job(newjob, inbg);

	return 0;
}

static int busy_loop(FILE * input)
{
	char *command;
	char *next_command = NULL;
	struct job newjob;
	pid_t  parent_pgrp;
	int i;
	int inbg;
	int status;
	newjob.job_list = &job_list;
	newjob.job_context = DEFAULT_CONTEXT;

	/* save current owner of TTY so we can restore it on exit */
	parent_pgrp = tcgetpgrp(0);

	command = (char *) xcalloc(BUFSIZ, sizeof(char));

	/* don't pay any attention to this signal; it just confuses 
	   things and isn't really meant for shells anyway */
	signal(SIGTTOU, SIG_IGN);

	while (1) {
		if (!job_list.fg) {
			/* no job is in the foreground */

			/* see if any background processes have exited */
			checkjobs(&job_list);

			if (!next_command) {
				if (get_command(input, command))
					break;
				next_command = command;
			}

			if (expand_arguments(next_command) == FALSE) {
				free(command);
				command = (char *) xcalloc(BUFSIZ, sizeof(char));
				next_command = NULL;
				continue;
			}

			if (!parse_command(&next_command, &newjob, &inbg) &&
				newjob.num_progs) {
				int pipefds[2] = {-1,-1};
				debug_printf( "job=%p fed to run_command by busy_loop()'\n", 
						&newjob);
				run_command(&newjob, inbg, pipefds);
			}
			else {
				free(command);
				command = (char *) xcalloc(BUFSIZ, sizeof(char));
				next_command = NULL;
			}
		} else {
			/* a job is running in the foreground; wait for it */
			i = 0;
			while (!job_list.fg->progs[i].pid ||
				   job_list.fg->progs[i].is_stopped == 1) i++;

			if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
				perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);

			if (WIFEXITED(status) || WIFSIGNALED(status)) {
				/* the child exited */
				job_list.fg->running_progs--;
				job_list.fg->progs[i].pid = 0;

#ifdef BB_FEATURE_SH_ENVIRONMENT
				last_return_code=WEXITSTATUS(status);
				debug_printf("'%s' exited -- return code %d\n",
						job_list.fg->text, last_return_code);
#endif
				if (!job_list.fg->running_progs) {
					/* child exited */
					remove_job(&job_list, job_list.fg);
					job_list.fg = NULL;
				}
			} else {
				/* the child was stopped */
				job_list.fg->stopped_progs++;
				job_list.fg->progs[i].is_stopped = 1;

				if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
					printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
						   "Stopped", job_list.fg->text);
					job_list.fg = NULL;
				}
			}

			if (!job_list.fg) {
				/* move the shell to the foreground */
				/* suppress messages when run from /linuxrc mag@sysgo.de */
				if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY)
					perror_msg("tcsetpgrp"); 
			}
		}
	}
	free(command);

	/* return controlling TTY back to parent process group before exiting */
	if (tcsetpgrp(0, parent_pgrp))
		perror_msg("tcsetpgrp");

	/* return exit status if called with "-c" */
	if (input == NULL && WIFEXITED(status))
		return WEXITSTATUS(status);
	
	return 0;
}


#ifdef BB_FEATURE_CLEAN_UP
void free_memory(void)
{
	if (cwd) {
		free(cwd);
	}
	if (local_pending_command)
		free(local_pending_command);

	if (job_list.fg && !job_list.fg->running_progs) {
		remove_job(&job_list, job_list.fg);
	}
}
#endif


int shell_main(int argc_l, char **argv_l)
{
	int opt, interactive=FALSE;
	FILE *input = stdin;
	argc = argc_l;
	argv = argv_l;

	/* These variables need re-initializing when recursing */
	shell_context = 0;
	local_pending_command = NULL;
	close_me_head = NULL;
	job_list.head = NULL;
	job_list.fg = NULL;
#ifdef BB_FEATURE_SH_ENVIRONMENT
	last_bg_pid=1;
	last_return_code=1;
	show_x_trace=FALSE;
#endif

	if (argv[0] && argv[0][0] == '-') {
		FILE *prof_input;
		prof_input = fopen("/etc/profile", "r");
		if (!prof_input) {
			printf( "Couldn't open file '/etc/profile'\n");
		} else {
			int tmp_fd = fileno(prof_input);
			mark_open(tmp_fd);	
			/* Now run the file */
			busy_loop(prof_input);
			fclose(prof_input);
			mark_closed(tmp_fd);
		}
	}

	while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
		switch (opt) {
			case 'c':
				input = NULL;
				if (local_pending_command != 0)
					error_msg_and_die("multiple -c arguments");
				local_pending_command = xstrdup(argv[optind]);
				optind++;
				argv = argv+optind;
				break;
#ifdef BB_FEATURE_SH_ENVIRONMENT
			case 'x':
				show_x_trace = TRUE;
				break;
#endif
			case 'i':
				interactive = TRUE;
				break;
			default:
				show_usage();
		}
	}
	/* 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(fileno(stdin)) && isatty(fileno(stdout))) {
		interactive=TRUE;
	}
	if (interactive==TRUE) {
		//printf( "optind=%d  argv[optind]='%s'\n", optind, argv[optind]);
		/* Looks like they want an interactive shell */
		printf( "\n\n" BB_BANNER " Built-in shell (lash)\n");
		printf( "Enter 'help' for a list of built-in commands.\n\n");
	} else if (local_pending_command==NULL) {
		//printf( "optind=%d  argv[optind]='%s'\n", optind, argv[optind]);
		input = xfopen(argv[optind], "r");
		mark_open(fileno(input));  /* be lazy, never mark this closed */
	}

	/* initialize the cwd -- this is never freed...*/
	cwd = xgetcwd(0);
	if (!cwd)
		cwd = unknown;

#ifdef BB_FEATURE_CLEAN_UP
	atexit(free_memory);
#endif

#ifdef BB_FEATURE_COMMAND_EDITING
	cmdedit_set_initial_prompt();
#else
	PS1 = NULL;
#endif
	
	return (busy_loop(input));
}