* Copyright (c) 2010 Denys Vlasenko
* Split from ash.c
*
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include "shell_common.h"
const char defifsvar[] ALIGN1 = "IFS= \t\n";
+const char defoptindvar[] ALIGN1 = "OPTIND=1";
+/* read builtin */
-int FAST_FUNC is_well_formed_var_name(const char *s, char terminator)
+/* Needs to be interruptible: shell must handle traps and shell-special signals
+ * while inside read. To implement this, be sure to not loop on EINTR
+ * and return errno == EINTR reliably.
+ */
+//TODO: use more efficient setvar() which takes a pointer to malloced "VAR=VAL"
+//string. hush naturally has it, and ash has setvareq().
+//Here we can simply store "VAR=" at buffer start and store read data directly
+//after "=", then pass buffer to setvar() to consume.
+const char* FAST_FUNC
+shell_builtin_read(struct builtin_read_params *params)
+{
+ struct pollfd pfd[1];
+#define fd (pfd[0].fd) /* -u FD */
+ unsigned err;
+ unsigned end_ms; /* -t TIMEOUT */
+ int nchars; /* -n NUM */
+ char **pp;
+ char *buffer;
+ char delim;
+ struct termios tty, old_tty;
+ const char *retval;
+ int bufpos; /* need to be able to hold -1 */
+ int startword;
+ smallint backslash;
+ char **argv;
+ const char *ifs;
+ int read_flags;
+
+ errno = err = 0;
+
+ argv = params->argv;
+ pp = argv;
+ while (*pp) {
+ if (endofname(*pp)[0] != '\0') {
+ /* Mimic bash message */
+ bb_error_msg("read: '%s': not a valid identifier", *pp);
+ return (const char *)(uintptr_t)1;
+ }
+ pp++;
+ }
+
+ nchars = 0; /* if != 0, -n is in effect */
+ if (params->opt_n) {
+ nchars = bb_strtou(params->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 (params->opt_t && !ENABLE_FEATURE_SH_READ_FRAC) {
+ end_ms = bb_strtou(params->opt_t, NULL, 10);
+ if (errno)
+ return "invalid timeout";
+ if (end_ms > UINT_MAX / 2048) /* be safely away from overflow */
+ end_ms = UINT_MAX / 2048;
+ end_ms *= 1000;
+ }
+ if (params->opt_t && ENABLE_FEATURE_SH_READ_FRAC) {
+ /* bash 4.3 (maybe earlier) supports -t N.NNNNNN */
+ char *p;
+ /* Eat up to three fractional digits */
+ int frac_digits = 3 + 1;
+
+ end_ms = bb_strtou(params->opt_t, &p, 10);
+ if (end_ms > UINT_MAX / 2048) /* be safely away from overflow */
+ end_ms = UINT_MAX / 2048;
+
+ if (errno) {
+ /* EINVAL = number is ok, but not NUL terminated */
+ if (errno != EINVAL || *p != '.')
+ return "invalid timeout";
+ /* Do not check the rest: bash allows "0.123456xyz" */
+ while (*++p && --frac_digits) {
+ end_ms *= 10;
+ end_ms += (*p - '0');
+ if ((unsigned char)(*p - '0') > 9)
+ return "invalid timeout";
+ }
+ }
+ while (--frac_digits > 0) {
+ end_ms *= 10;
+ }
+ }
+
+ fd = STDIN_FILENO;
+ if (params->opt_u) {
+ fd = bb_strtou(params->opt_u, NULL, 10);
+ if (fd < 0 || errno)
+ return "invalid file descriptor";
+ }
+
+ if (params->opt_t && end_ms == 0) {
+ /* "If timeout is 0, read returns immediately, without trying
+ * to read any data. The exit status is 0 if input is available
+ * on the specified file descriptor, non-zero otherwise."
+ * bash seems to ignore -p PROMPT for this use case.
+ */
+ int r;
+ pfd[0].events = POLLIN;
+ r = poll(pfd, 1, /*timeout:*/ 0);
+ /* Return 0 only if poll returns 1 ("one fd ready"), else return 1: */
+ return (const char *)(uintptr_t)(r <= 0);
+ }
+
+ if (params->opt_p && isatty(fd)) {
+ fputs(params->opt_p, stderr);
+ fflush_all();
+ }
+
+ ifs = params->ifs;
+ if (ifs == NULL)
+ ifs = defifs;
+
+ read_flags = params->read_flags;
+ if (nchars || (read_flags & BUILTIN_READ_SILENT)) {
+ tcgetattr(fd, &tty);
+ old_tty = tty;
+ if (nchars) {
+ tty.c_lflag &= ~ICANON;
+ // Setting it to more than 1 breaks poll():
+ // it blocks even if there's data. !??
+ //tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
+ /* reads will block only if < 1 char is available */
+ tty.c_cc[VMIN] = 1;
+ /* no timeout (reads block forever) */
+ tty.c_cc[VTIME] = 0;
+ }
+ 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 (params->opt_t)
+ end_ms += (unsigned)monotonic_ms();
+ buffer = NULL;
+ bufpos = 0;
+ delim = params->opt_d ? params->opt_d[0] : '\n';
+ do {
+ char c;
+ int timeout;
+
+ if ((bufpos & 0xff) == 0)
+ buffer = xrealloc(buffer, bufpos + 0x101);
+
+ timeout = -1;
+ if (params->opt_t) {
+ timeout = end_ms - (unsigned)monotonic_ms();
+ /* ^^^^^^^^^^^^^ all values are unsigned,
+ * wrapping math is used here, good even if
+ * 32-bit unix time wrapped (year 2038+).
+ */
+ if (timeout <= 0) { /* already late? */
+ retval = (const char *)(uintptr_t)1;
+ goto ret;
+ }
+ }
+
+ /* We must poll even if timeout is -1:
+ * we want to be interrupted if signal arrives,
+ * regardless of SA_RESTART-ness of that signal!
+ */
+ errno = 0;
+ pfd[0].events = POLLIN;
+ if (poll(pfd, 1, timeout) <= 0) {
+ /* timed out, or EINTR */
+ err = errno;
+ retval = (const char *)(uintptr_t)1;
+ goto ret;
+ }
+ if (read(fd, &buffer[bufpos], 1) != 1) {
+ err = errno;
+ retval = (const char *)(uintptr_t)1;
+ break;
+ }
+
+ c = buffer[bufpos];
+ if (c == '\0')
+ continue;
+ if (!(read_flags & BUILTIN_READ_RAW)) {
+ if (backslash) {
+ backslash = 0;
+ if (c != '\n')
+ goto put;
+ continue;
+ }
+ if (c == '\\') {
+ backslash = 1;
+ continue;
+ }
+ }
+ if (c == delim) /* '\n' or -d CHAR */
+ break;
+
+ /* $IFS splitting. NOT done if we run "read"
+ * without variable names (bash compat).
+ * Thus, "read" and "read REPLY" are not the same.
+ */
+ if (!params->opt_d && 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;
+ params->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';
+
+ /* Last variable takes the entire remainder with delimiters
+ * (sans trailing whitespace $IFS),
+ * but ***only "if there are fewer vars than fields"(c)***!
+ * The "X:Y:" case below: there are two fields,
+ * and therefore last delimiter (:) is eaten:
+ * IFS=": "
+ * echo "X:Y:Z:" | (read x y; echo "|$x|$y|") # |X|Y:Z:|
+ * echo "X:Y:Z" | (read x y; echo "|$x|$y|") # |X|Y:Z|
+ * echo "X:Y:" | (read x y; echo "|$x|$y|") # |X|Y|, not |X|Y:|
+ * echo "X:Y : " | (read x y; echo "|$x|$y|") # |X|Y|
+ */
+ if (bufpos >= 0
+ && strchr(ifs, buffer[bufpos]) != NULL
+ ) {
+ /* There _is_ a non-whitespace IFS char */
+ /* Skip whitespace IFS char before it */
+ while (--bufpos >= 0
+ && isspace(buffer[bufpos])
+ && strchr(ifs, buffer[bufpos]) != NULL
+ ) {
+ continue;
+ }
+ /* Are there $IFS chars? */
+ if (strcspn(buffer, ifs) >= ++bufpos) {
+ /* No: last var takes one field, not more */
+ /* So, drop trailing IFS delims */
+ buffer[bufpos] = '\0';
+ }
+ }
+
+ /* Use the remainder as a value for the next variable */
+ params->setvar(*argv, buffer);
+ /* Set the rest to "" */
+ while (*++argv)
+ params->setvar(*argv, "");
+ } else {
+ /* Note: no $IFS removal */
+ buffer[bufpos] = '\0';
+ params->setvar("REPLY", buffer);
+ }
+
+ ret:
+ free(buffer);
+ if (read_flags & BUILTIN_READ_SILENT)
+ tcsetattr(fd, TCSANOW, &old_tty);
+
+ errno = err;
+ return retval;
+#undef fd
+}
+
+/* ulimit builtin */
+
+struct limits {
+ uint8_t cmd; /* RLIMIT_xxx fit into it */
+ uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */
+};
+
+static const struct limits limits_tbl[] = {
+ { RLIMIT_CORE, 9, }, // -c
+ { RLIMIT_DATA, 10, }, // -d
+ { RLIMIT_NICE, 0, }, // -e
+ { RLIMIT_FSIZE, 9, }, // -f
+#define LIMIT_F_IDX 3
+#ifdef RLIMIT_SIGPENDING
+ { RLIMIT_SIGPENDING, 0, }, // -i
+#endif
+#ifdef RLIMIT_MEMLOCK
+ { RLIMIT_MEMLOCK, 10, }, // -l
+#endif
+#ifdef RLIMIT_RSS
+ { RLIMIT_RSS, 10, }, // -m
+#endif
+#ifdef RLIMIT_NOFILE
+ { RLIMIT_NOFILE, 0, }, // -n
+#endif
+#ifdef RLIMIT_MSGQUEUE
+ { RLIMIT_MSGQUEUE, 0, }, // -q
+#endif
+#ifdef RLIMIT_RTPRIO
+ { RLIMIT_RTPRIO, 0, }, // -r
+#endif
+#ifdef RLIMIT_STACK
+ { RLIMIT_STACK, 10, }, // -s
+#endif
+#ifdef RLIMIT_CPU
+ { RLIMIT_CPU, 0, }, // -t
+#endif
+#ifdef RLIMIT_NPROC
+ { RLIMIT_NPROC, 0, }, // -u
+#endif
+#ifdef RLIMIT_AS
+ { RLIMIT_AS, 10, }, // -v
+#endif
+#ifdef RLIMIT_LOCKS
+ { RLIMIT_LOCKS, 0, }, // -x
+#endif
+};
+// bash also shows:
+//pipe size (512 bytes, -p) 8
+
+static const char limits_help[] ALIGN1 =
+ "core file size (blocks)" // -c
+ "\0""data seg size (kb)" // -d
+ "\0""scheduling priority" // -e
+ "\0""file size (blocks)" // -f
+#ifdef RLIMIT_SIGPENDING
+ "\0""pending signals" // -i
+#endif
+#ifdef RLIMIT_MEMLOCK
+ "\0""max locked memory (kb)" // -l
+#endif
+#ifdef RLIMIT_RSS
+ "\0""max memory size (kb)" // -m
+#endif
+#ifdef RLIMIT_NOFILE
+ "\0""open files" // -n
+#endif
+#ifdef RLIMIT_MSGQUEUE
+ "\0""POSIX message queues (bytes)" // -q
+#endif
+#ifdef RLIMIT_RTPRIO
+ "\0""real-time priority" // -r
+#endif
+#ifdef RLIMIT_STACK
+ "\0""stack size (kb)" // -s
+#endif
+#ifdef RLIMIT_CPU
+ "\0""cpu time (seconds)" // -t
+#endif
+#ifdef RLIMIT_NPROC
+ "\0""max user processes" // -u
+#endif
+#ifdef RLIMIT_AS
+ "\0""virtual memory (kb)" // -v
+#endif
+#ifdef RLIMIT_LOCKS
+ "\0""file locks" // -x
+#endif
+;
+
+static const char limit_chars[] ALIGN1 =
+ "c"
+ "d"
+ "e"
+ "f"
+#ifdef RLIMIT_SIGPENDING
+ "i"
+#endif
+#ifdef RLIMIT_MEMLOCK
+ "l"
+#endif
+#ifdef RLIMIT_RSS
+ "m"
+#endif
+#ifdef RLIMIT_NOFILE
+ "n"
+#endif
+#ifdef RLIMIT_MSGQUEUE
+ "q"
+#endif
+#ifdef RLIMIT_RTPRIO
+ "r"
+#endif
+#ifdef RLIMIT_STACK
+ "s"
+#endif
+#ifdef RLIMIT_CPU
+ "t"
+#endif
+#ifdef RLIMIT_NPROC
+ "u"
+#endif
+#ifdef RLIMIT_AS
+ "v"
+#endif
+#ifdef RLIMIT_LOCKS
+ "x"
+#endif
+;
+
+/* "-": treat args as parameters of option with ASCII code 1 */
+static const char ulimit_opt_string[] ALIGN1 = "-HSa"
+ "c::"
+ "d::"
+ "e::"
+ "f::"
+#ifdef RLIMIT_SIGPENDING
+ "i::"
+#endif
+#ifdef RLIMIT_MEMLOCK
+ "l::"
+#endif
+#ifdef RLIMIT_RSS
+ "m::"
+#endif
+#ifdef RLIMIT_NOFILE
+ "n::"
+#endif
+#ifdef RLIMIT_MSGQUEUE
+ "q::"
+#endif
+#ifdef RLIMIT_RTPRIO
+ "r::"
+#endif
+#ifdef RLIMIT_STACK
+ "s::"
+#endif
+#ifdef RLIMIT_CPU
+ "t::"
+#endif
+#ifdef RLIMIT_NPROC
+ "u::"
+#endif
+#ifdef RLIMIT_AS
+ "v::"
+#endif
+#ifdef RLIMIT_LOCKS
+ "x::"
+#endif
+;
+
+enum {
+ OPT_hard = (1 << 0),
+ OPT_soft = (1 << 1),
+ OPT_all = (1 << 2),
+};
+
+static void printlim(unsigned opts, const struct rlimit *limit,
+ const struct limits *l)
+{
+ rlim_t val;
+
+ val = limit->rlim_max;
+ if (opts & OPT_soft)
+ val = limit->rlim_cur;
+
+ if (val == RLIM_INFINITY)
+ puts("unlimited");
+ else {
+ val >>= l->factor_shift;
+ printf("%llu\n", (long long) val);
+ }
+}
+
+int FAST_FUNC
+shell_builtin_ulimit(char **argv)
{
- if (!s || !(isalpha(*s) || *s == '_'))
- return 0;
+ struct rlimit limit;
+ unsigned opt_cnt;
+ unsigned opts;
+ unsigned argc;
+ unsigned i;
+
+ /* We can't use getopt32: need to handle commands like
+ * ulimit 123 -c2 -l 456
+ */
+
+ /* In case getopt() was already called:
+ * reset libc getopt() internal state.
+ */
+ GETOPT_RESET();
+
+// bash 4.4.23:
+//
+// -H and/or -S change meaning even of options *before* them: ulimit -f 2000 -H
+// sets hard limit, ulimit -a -H prints hard limits.
+//
+// -a is equivalent for requesting all limits to be shown.
+//
+// If -a is specified, attempts to set limits are ignored:
+// ulimit -m 1000; ulimit -m 2000 -a
+// shows 1000, not 2000. HOWEVER, *implicit* -f form "ulimit 2000 -a"
+// DOES set -f limit [we don't implement this quirk], "ulimit -a 2000" does not.
+// Options are still parsed: ulimit -az complains about unknown -z opt.
+//
+// -a is not cumulative: "ulimit -a -a" = "ulimit -a -f -m" = "ulimit -a"
+//
+// -HSa can be combined in one argument and with one other option (example: -Sm),
+// but other options can't: limit value is an optional argument,
+// thus "-mf" means "-m f", f is the parameter of -m.
+//
+// Limit can be set and then printed: ulimit -m 2000 -m
+// If set more than once, they are set and printed in order:
+// try ulimit -m -m 1000 -m -m 2000 -m -m 3000 -m
+//
+// Limits are shown in the order of options given:
+// ulimit -m -f is not the same as ulimit -f -m.
+//
+// If both -S and -H are given, show soft limit.
+//
+// Short printout (limit value only) is printed only if just one option
+// is given: ulimit -m. ulimit -f -m prints verbose lines.
+// ulimit -f -f prints same verbose line twice.
+// ulimit -m 10000 -f prints verbose line for -f.
+
+ argc = string_array_len(argv);
+
+ /* First pass over options: detect -H/-S/-a status,
+ * and "bare ulimit" and "only one option" cases
+ * by counting other opts.
+ */
+ opt_cnt = 0;
+ opts = 0;
+ while (1) {
+ int opt_char = getopt(argc, argv, ulimit_opt_string);
+
+ if (opt_char == -1)
+ break;
+ if (opt_char == 'H') {
+ opts |= OPT_hard;
+ continue;
+ }
+ if (opt_char == 'S') {
+ opts |= OPT_soft;
+ continue;
+ }
+ if (opt_char == 'a') {
+ opts |= OPT_all;
+ continue;
+ }
+ if (opt_char == '?') {
+ /* bad option. getopt already complained. */
+ return EXIT_FAILURE;
+ }
+ opt_cnt++;
+ } /* while (there are options) */
+
+ if (!(opts & (OPT_hard | OPT_soft)))
+ opts |= (OPT_hard | OPT_soft);
+ if (opts & OPT_all) {
+ const char *help = limits_help;
+ for (i = 0; i < ARRAY_SIZE(limits_tbl); i++) {
+ getrlimit(limits_tbl[i].cmd, &limit);
+ printf("%-32s(-%c) ", help, limit_chars[i]);
+ printlim(opts, &limit, &limits_tbl[i]);
+ help += strlen(help) + 1;
+ }
+ return EXIT_SUCCESS;
+ }
+
+ /* Second pass: set or print limits, in order */
+ GETOPT_RESET();
+ while (1) {
+ char *val_str;
+ int opt_char = getopt(argc, argv, ulimit_opt_string);
+
+ if (opt_char == -1)
+ break;
+ if (opt_char == 'H')
+ continue;
+ if (opt_char == 'S')
+ continue;
+ //if (opt_char == 'a') - impossible
+
+ if (opt_char == 1) /* if "ulimit NNN", -f is assumed */
+ opt_char = 'f';
+ i = strchrnul(limit_chars, opt_char) - limit_chars;
+ //if (i >= ARRAY_SIZE(limits_tbl)) - bad option, impossible
+
+ val_str = optarg;
+ if (!val_str && argv[optind] && argv[optind][0] != '-')
+ val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
+
+ getrlimit(limits_tbl[i].cmd, &limit);
+ if (!val_str) {
+ if (opt_cnt > 1)
+ printf("%-32s(-%c) ", nth_string(limits_help, i), limit_chars[i]);
+ printlim(opts, &limit, &limits_tbl[i]);
+ } else {
+ rlim_t val = RLIM_INFINITY;
+ if (strcmp(val_str, "unlimited") != 0) {
+ if (sizeof(val) == sizeof(int))
+ val = bb_strtou(val_str, NULL, 10);
+ else if (sizeof(val) == sizeof(long))
+ val = bb_strtoul(val_str, NULL, 10);
+ else
+ val = bb_strtoull(val_str, NULL, 10);
+ if (errno) {
+ bb_error_msg("invalid number '%s'", val_str);
+ return EXIT_FAILURE;
+ }
+ val <<= limits_tbl[i].factor_shift;
+ }
+//bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val);
+ /* from man bash: "If neither -H nor -S
+ * is specified, both the soft and hard
+ * limits are set. */
+ if (opts & OPT_hard)
+ limit.rlim_max = val;
+ if (opts & OPT_soft)
+ limit.rlim_cur = val;
+//bb_error_msg("setrlimit(%d, %lld, %lld)", limits_tbl[i].cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
+ if (setrlimit(limits_tbl[i].cmd, &limit) < 0) {
+ bb_simple_perror_msg("error setting limit");
+ return EXIT_FAILURE;
+ }
+ }
+ } /* while (there are options) */
- do
- s++;
- while (isalnum(*s) || *s == '_');
+ if (opt_cnt == 0) {
+ /* "bare ulimit": treat it as if it was -f */
+ getrlimit(limits_tbl[LIMIT_F_IDX].cmd, &limit);
+ printlim(opts, &limit, &limits_tbl[LIMIT_F_IDX]);
+ }
- return *s == terminator;
+ return EXIT_SUCCESS;
}
projects / oweals / busybox.git / blobdiff