| /* 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 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 */ |
| |
| /* 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 (!(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; |
| if (c == '\0') |
| continue; |
| |
| /* $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 */ |
| }; |
| |
| /* Order of entries matches order in which bash prints "ulimit -a" */ |
| static const struct limits limits_tbl[] ALIGN2 = { |
| { RLIMIT_CORE, 9, }, // -c |
| { RLIMIT_DATA, 10, }, // -d |
| #ifdef RLIMIT_NICE |
| { RLIMIT_NICE, 0, }, // -e |
| #define LIMIT_F_IDX 3 |
| #else |
| /* for example, Hurd */ |
| #define LIMIT_F_IDX 2 |
| #endif |
| { RLIMIT_FSIZE, 9, }, // -f |
| #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 |
| }; |
| // 1) bash also shows: |
| //pipe size (512 bytes, -p) 8 |
| // 2) RLIMIT_RTTIME ("timeout for RT tasks in us") is not in the table |
| |
| static const char limits_help[] ALIGN1 = |
| "core file size (blocks)" // -c |
| "\0""data seg size (kb)" // -d |
| #ifdef RLIMIT_NICE |
| "\0""scheduling priority" // -e |
| #endif |
| "\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" |
| #ifdef RLIMIT_NICE |
| "e" |
| #endif |
| "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::" |
| #ifdef RLIMIT_NICE |
| "e::" |
| #endif |
| "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) |
| { |
| 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) */ |
| |
| if (opt_cnt == 0) { |
| /* "bare ulimit": treat it as if it was -f */ |
| getrlimit(RLIMIT_FSIZE, &limit); |
| printlim(opts, &limit, &limits_tbl[LIMIT_F_IDX]); |
| } |
| |
| return EXIT_SUCCESS; |
| } |