1 /* vi: set sw=4 ts=4: */
3 * Adapted from ash applet code
5 * This code is derived from software contributed to Berkeley by
8 * Copyright (c) 1989, 1991, 1993, 1994
9 * The Regents of the University of California. All rights reserved.
11 * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
12 * was re-ported from NetBSD and debianized.
14 * Copyright (c) 2010 Denys Vlasenko
17 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
20 #include "shell_common.h"
21 #include <sys/resource.h> /* getrlimit */
23 const char defifsvar[] ALIGN1 = "IFS= \t\n";
24 const char defoptindvar[] ALIGN1 = "OPTIND=1";
27 int FAST_FUNC is_well_formed_var_name(const char *s, char terminator)
29 if (!s || !(isalpha(*s) || *s == '_'))
34 while (isalnum(*s) || *s == '_');
36 return *s == terminator;
41 /* Needs to be interruptible: shell must handle traps and shell-special signals
42 * while inside read. To implement this, be sure to not loop on EINTR
43 * and return errno == EINTR reliably.
45 //TODO: use more efficient setvar() which takes a pointer to malloced "VAR=VAL"
46 //string. hush naturally has it, and ash has setvareq().
47 //Here we can simply store "VAR=" at buffer start and store read data directly
48 //after "=", then pass buffer to setvar() to consume.
50 shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
62 #define fd (pfd[0].fd) /* -u FD */
64 unsigned end_ms; /* -t TIMEOUT */
65 int nchars; /* -n NUM */
69 struct termios tty, old_tty;
71 int bufpos; /* need to be able to hold -1 */
79 if (!is_well_formed_var_name(*pp, '\0')) {
80 /* Mimic bash message */
81 bb_error_msg("read: '%s': not a valid identifier", *pp);
82 return (const char *)(uintptr_t)1;
87 nchars = 0; /* if != 0, -n is in effect */
89 nchars = bb_strtou(opt_n, NULL, 10);
90 if (nchars < 0 || errno)
91 return "invalid count";
92 /* note: "-n 0": off (bash 3.2 does this too) */
96 if (opt_t && !ENABLE_FEATURE_SH_READ_FRAC) {
97 end_ms = bb_strtou(opt_t, NULL, 10);
99 return "invalid timeout";
100 if (end_ms > UINT_MAX / 2048) /* be safely away from overflow */
101 end_ms = UINT_MAX / 2048;
104 if (opt_t && ENABLE_FEATURE_SH_READ_FRAC) {
105 /* bash 4.3 (maybe earlier) supports -t N.NNNNNN */
107 /* Eat up to three fractional digits */
108 int frac_digits = 3 + 1;
110 end_ms = bb_strtou(opt_t, &p, 10);
111 if (end_ms > UINT_MAX / 2048) /* be safely away from overflow */
112 end_ms = UINT_MAX / 2048;
115 /* EINVAL = number is ok, but not NUL terminated */
116 if (errno != EINVAL || *p != '.')
117 return "invalid timeout";
118 /* Do not check the rest: bash allows "0.123456xyz" */
119 while (*++p && --frac_digits) {
121 end_ms += (*p - '0');
122 if ((unsigned char)(*p - '0') > 9)
123 return "invalid timeout";
126 while (--frac_digits > 0) {
133 fd = bb_strtou(opt_u, NULL, 10);
135 return "invalid file descriptor";
138 if (opt_t && end_ms == 0) {
139 /* "If timeout is 0, read returns immediately, without trying
140 * to read any data. The exit status is 0 if input is available
141 * on the specified file descriptor, non-zero otherwise."
142 * bash seems to ignore -p PROMPT for this use case.
145 pfd[0].events = POLLIN;
146 r = poll(pfd, 1, /*timeout:*/ 0);
147 /* Return 0 only if poll returns 1 ("one fd ready"), else return 1: */
148 return (const char *)(uintptr_t)(r <= 0);
151 if (opt_p && isatty(fd)) {
152 fputs(opt_p, stderr);
159 if (nchars || (read_flags & BUILTIN_READ_SILENT)) {
163 tty.c_lflag &= ~ICANON;
164 // Setting it to more than 1 breaks poll():
165 // it blocks even if there's data. !??
166 //tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
167 /* reads will block only if < 1 char is available */
169 /* no timeout (reads block forever) */
172 if (read_flags & BUILTIN_READ_SILENT) {
173 tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
175 /* This forces execution of "restoring" tcgetattr later */
176 read_flags |= BUILTIN_READ_SILENT;
177 /* if tcgetattr failed, tcsetattr will fail too.
178 * Ignoring, it's harmless. */
179 tcsetattr(fd, TCSANOW, &tty);
182 retval = (const char *)(uintptr_t)0;
186 end_ms += (unsigned)monotonic_ms();
189 delim = opt_d ? *opt_d : '\n';
194 if ((bufpos & 0xff) == 0)
195 buffer = xrealloc(buffer, bufpos + 0x101);
199 timeout = end_ms - (unsigned)monotonic_ms();
200 /* ^^^^^^^^^^^^^ all values are unsigned,
201 * wrapping math is used here, good even if
202 * 32-bit unix time wrapped (year 2038+).
204 if (timeout <= 0) { /* already late? */
205 retval = (const char *)(uintptr_t)1;
210 /* We must poll even if timeout is -1:
211 * we want to be interrupted if signal arrives,
212 * regardless of SA_RESTART-ness of that signal!
215 pfd[0].events = POLLIN;
216 if (poll(pfd, 1, timeout) <= 0) {
217 /* timed out, or EINTR */
219 retval = (const char *)(uintptr_t)1;
222 if (read(fd, &buffer[bufpos], 1) != 1) {
224 retval = (const char *)(uintptr_t)1;
231 if (!(read_flags & BUILTIN_READ_RAW)) {
243 if (c == delim) /* '\n' or -d CHAR */
246 /* $IFS splitting. NOT done if we run "read"
247 * without variable names (bash compat).
248 * Thus, "read" and "read REPLY" are not the same.
250 if (!opt_d && argv[0]) {
251 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */
252 const char *is_ifs = strchr(ifs, c);
253 if (startword && is_ifs) {
256 /* it is a non-space ifs char */
258 if (startword == 1) /* first one? */
259 continue; /* yes, it is not next word yet */
262 if (argv[1] != NULL && is_ifs) {
263 buffer[bufpos] = '\0';
265 setvar(*argv, buffer);
267 /* can we skip one non-space ifs char? (2: yes) */
268 startword = isspace(c) ? 2 : 1;
277 /* Remove trailing space $IFS chars */
278 while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL)
280 buffer[bufpos + 1] = '\0';
281 /* Use the remainder as a value for the next variable */
282 setvar(*argv, buffer);
283 /* Set the rest to "" */
287 /* Note: no $IFS removal */
288 buffer[bufpos] = '\0';
289 setvar("REPLY", buffer);
294 if (read_flags & BUILTIN_READ_SILENT)
295 tcsetattr(fd, TCSANOW, &old_tty);
305 uint8_t cmd; /* RLIMIT_xxx fit into it */
306 uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */
311 static const struct limits limits_tbl[] = {
313 { RLIMIT_FSIZE, 9, 'f', "file size (blocks)" },
316 { RLIMIT_CPU, 0, 't', "cpu time (seconds)" },
319 { RLIMIT_DATA, 10, 'd', "data seg size (kb)" },
322 { RLIMIT_STACK, 10, 's', "stack size (kb)" },
325 { RLIMIT_CORE, 9, 'c', "core file size (blocks)" },
328 { RLIMIT_RSS, 10, 'm', "resident set size (kb)" },
330 #ifdef RLIMIT_MEMLOCK
331 { RLIMIT_MEMLOCK, 10, 'l', "locked memory (kb)" },
334 { RLIMIT_NPROC, 0, 'p', "processes" },
337 { RLIMIT_NOFILE, 0, 'n', "file descriptors" },
340 { RLIMIT_AS, 10, 'v', "address space (kb)" },
343 { RLIMIT_LOCKS, 0, 'w', "locks" },
346 { RLIMIT_NICE, 0, 'e', "scheduling priority" },
349 { RLIMIT_RTPRIO, 0, 'r', "real-time priority" },
358 /* "-": treat args as parameters of option with ASCII code 1 */
359 static const char ulimit_opt_string[] ALIGN1 = "-HSa"
378 #ifdef RLIMIT_MEMLOCK
401 static void printlim(unsigned opts, const struct rlimit *limit,
402 const struct limits *l)
406 val = limit->rlim_max;
407 if (!(opts & OPT_hard))
408 val = limit->rlim_cur;
410 if (val == RLIM_INFINITY)
413 val >>= l->factor_shift;
414 printf("%llu\n", (long long) val);
419 shell_builtin_ulimit(char **argv)
424 /* We can't use getopt32: need to handle commands like
425 * ulimit 123 -c2 -l 456
428 /* In case getopt() was already called:
429 * reset libc getopt() internal state.
433 argc = string_array_len(argv);
438 const struct limits *l;
439 int opt_char = getopt(argc, argv, ulimit_opt_string);
443 if (opt_char == 'H') {
447 if (opt_char == 'S') {
452 if (opt_char == 'a') {
453 for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
454 getrlimit(l->cmd, &limit);
455 printf("-%c: %-30s ", l->option, l->name);
456 printlim(opts, &limit, l);
463 for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
464 if (opt_char == l->option) {
467 getrlimit(l->cmd, &limit);
470 if (!val_str && argv[optind] && argv[optind][0] != '-')
471 val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
475 if (strcmp(val_str, "unlimited") == 0)
478 if (sizeof(val) == sizeof(int))
479 val = bb_strtou(val_str, NULL, 10);
480 else if (sizeof(val) == sizeof(long))
481 val = bb_strtoul(val_str, NULL, 10);
483 val = bb_strtoull(val_str, NULL, 10);
485 bb_error_msg("invalid number '%s'", val_str);
488 val <<= l->factor_shift;
490 //bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val);
491 /* from man bash: "If neither -H nor -S
492 * is specified, both the soft and hard
495 opts = OPT_hard + OPT_soft;
497 limit.rlim_max = val;
499 limit.rlim_cur = val;
500 //bb_error_msg("setrlimit(%d, %lld, %lld)", l->cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
501 if (setrlimit(l->cmd, &limit) < 0) {
502 bb_perror_msg("error setting limit");
506 printlim(opts, &limit, l);
510 } /* for (every possible opt) */
512 if (l == &limits_tbl[ARRAY_SIZE(limits_tbl)]) {
513 /* bad option. getopt already complained. */
516 } /* while (there are options) */