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
|
/* vi: set sw=4 ts=4: */
/*
* Adapted from ash applet code
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Copyright (c) 1989, 1991, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
* was re-ported from NetBSD and debianized.
*
* Copyright (c) 2010 Denys Vlasenko
* Split from ash.c
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
#include "libbb.h"
#include "shell_common.h"
#include "builtin_read.h"
const char* FAST_FUNC
shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
char **argv,
const char *ifs,
int read_flags,
const char *opt_n,
const char *opt_p,
const char *opt_t,
const char *opt_u
)
{
unsigned end_ms; /* -t TIMEOUT */
int fd; /* -u FD */
int nchars; /* -n NUM */
char *buffer;
struct termios tty, old_tty;
const char *retval;
int bufpos; /* need to be able to hold -1 */
int startword;
smallint backslash;
nchars = 0; /* if != 0, -n is in effect */
if (opt_n) {
nchars = bb_strtou(opt_n, NULL, 10);
if (nchars < 0 || errno)
return "invalid count";
/* note: "-n 0": off (bash 3.2 does this too) */
}
end_ms = 0;
if (opt_t) {
end_ms = bb_strtou(opt_t, NULL, 10);
if (errno || end_ms > UINT_MAX / 2048)
return "invalid timeout";
end_ms *= 1000;
#if 0 /* even bash has no -t N.NNN support */
ts.tv_sec = bb_strtou(opt_t, &p, 10);
ts.tv_usec = 0;
/* EINVAL means number is ok, but not terminated by NUL */
if (*p == '.' && errno == EINVAL) {
char *p2;
if (*++p) {
int scale;
ts.tv_usec = bb_strtou(p, &p2, 10);
if (errno)
return "invalid timeout";
scale = p2 - p;
/* normalize to usec */
if (scale > 6)
return "invalid timeout";
while (scale++ < 6)
ts.tv_usec *= 10;
}
} else if (ts.tv_sec < 0 || errno) {
return "invalid timeout";
}
if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */
return "invalid timeout";
}
#endif /* if 0 */
}
fd = STDIN_FILENO;
if (opt_u) {
fd = bb_strtou(opt_u, NULL, 10);
if (fd < 0 || errno)
return "invalid file descriptor";
}
if (opt_p && isatty(fd)) {
fputs(opt_p, stderr);
fflush_all();
}
if (ifs == NULL)
ifs = defifs;
if (nchars || (read_flags & BUILTIN_READ_SILENT)) {
tcgetattr(fd, &tty);
old_tty = tty;
if (nchars) {
tty.c_lflag &= ~ICANON;
tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
}
if (read_flags & BUILTIN_READ_SILENT) {
tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
}
/* This forces execution of "restoring" tcgetattr later */
read_flags |= BUILTIN_READ_SILENT;
/* if tcgetattr failed, tcsetattr will fail too.
* Ignoring, it's harmless. */
tcsetattr(fd, TCSANOW, &tty);
}
retval = (const char *)(uintptr_t)0;
startword = 1;
backslash = 0;
if (end_ms) /* NB: end_ms stays nonzero: */
end_ms = ((unsigned)monotonic_ms() + end_ms) | 1;
buffer = NULL;
bufpos = 0;
do {
char c;
if (end_ms) {
int timeout;
struct pollfd pfd[1];
pfd[0].fd = fd;
pfd[0].events = POLLIN;
timeout = end_ms - (unsigned)monotonic_ms();
if (timeout <= 0 /* already late? */
|| safe_poll(pfd, 1, timeout) != 1 /* no? wait... */
) { /* timed out! */
retval = (const char *)(uintptr_t)1;
goto ret;
}
}
if ((bufpos & 0xff) == 0)
buffer = xrealloc(buffer, bufpos + 0x100);
if (nonblock_safe_read(fd, &buffer[bufpos], 1) != 1) {
retval = (const char *)(uintptr_t)1;
break;
}
c = buffer[bufpos];
if (c == '\0')
continue;
if (backslash) {
backslash = 0;
if (c != '\n')
goto put;
continue;
}
if (!(read_flags & BUILTIN_READ_RAW) && c == '\\') {
backslash = 1;
continue;
}
if (c == '\n')
break;
/* $IFS splitting. NOT done if we run "read"
* without variable names (bash compat).
* Thus, "read" and "read REPLY" are not the same.
*/
if (argv[0]) {
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */
const char *is_ifs = strchr(ifs, c);
if (startword && is_ifs) {
if (isspace(c))
continue;
/* it is a non-space ifs char */
startword--;
if (startword == 1) /* first one? */
continue; /* yes, it is not next word yet */
}
startword = 0;
if (argv[1] != NULL && is_ifs) {
buffer[bufpos] = '\0';
bufpos = 0;
setvar(*argv, buffer);
argv++;
/* can we skip one non-space ifs char? (2: yes) */
startword = isspace(c) ? 2 : 1;
continue;
}
}
put:
bufpos++;
} while (--nchars);
if (argv[0]) {
/* Remove trailing space $IFS chars */
while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL)
continue;
buffer[bufpos + 1] = '\0';
/* Use the remainder as a value for the next variable */
setvar(*argv, buffer);
/* Set the rest to "" */
while (*++argv)
setvar(*argv, "");
} else {
/* Note: no $IFS removal */
buffer[bufpos] = '\0';
setvar("REPLY", buffer);
}
ret:
free(buffer);
if (read_flags & BUILTIN_READ_SILENT)
tcsetattr(fd, TCSANOW, &old_tty);
return retval;
}
|
