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/* 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";
int FAST_FUNC is_well_formed_var_name(const char *s, char terminator)
{
if (!s || !(isalpha(*s) || *s == '_'))
return 0;
do
s++;
while (isalnum(*s) || *s == '_');
return *s == terminator;
}
/* read builtin */
/* Needs to be interruptible: shell mush 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(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 err;
unsigned end_ms; /* -t TIMEOUT */
int fd; /* -u FD */
int nchars; /* -n NUM */
char **pp;
char *buffer;
struct termios tty, old_tty;
const char *retval;
int bufpos; /* need to be able to hold -1 */
int startword;
smallint backslash;
errno = err = 0;
pp = argv;
while (*pp) {
if (!is_well_formed_var_name(*pp, '\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 (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;
struct pollfd pfd[1];
int timeout;
if ((bufpos & 0xff) == 0)
buffer = xrealloc(buffer, bufpos + 0x100);
timeout = -1;
if (end_ms) {
timeout = end_ms - (unsigned)monotonic_ms();
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].fd = fd;
pfd[0].events = POLLIN;
if (poll(pfd, 1, timeout) != 1) {
/* 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 (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);
errno = err;
return retval;
}
/* ulimit builtin */
struct limits {
uint8_t cmd; /* RLIMIT_xxx fit into it */
uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */
char option;
const char *name;
};
static const struct limits limits_tbl[] = {
#ifdef RLIMIT_FSIZE
{ RLIMIT_FSIZE, 9, 'f', "file size (blocks)" },
#endif
#ifdef RLIMIT_CPU
{ RLIMIT_CPU, 0, 't', "cpu time (seconds)" },
#endif
#ifdef RLIMIT_DATA
{ RLIMIT_DATA, 10, 'd', "data seg size (kb)" },
#endif
#ifdef RLIMIT_STACK
{ RLIMIT_STACK, 10, 's', "stack size (kb)" },
#endif
#ifdef RLIMIT_CORE
{ RLIMIT_CORE, 9, 'c', "core file size (blocks)" },
#endif
#ifdef RLIMIT_RSS
{ RLIMIT_RSS, 10, 'm', "resident set size (kb)" },
#endif
#ifdef RLIMIT_MEMLOCK
{ RLIMIT_MEMLOCK, 10, 'l', "locked memory (kb)" },
#endif
#ifdef RLIMIT_NPROC
{ RLIMIT_NPROC, 0, 'p', "processes" },
#endif
#ifdef RLIMIT_NOFILE
{ RLIMIT_NOFILE, 0, 'n', "file descriptors" },
#endif
#ifdef RLIMIT_AS
{ RLIMIT_AS, 10, 'v', "address space (kb)" },
#endif
#ifdef RLIMIT_LOCKS
{ RLIMIT_LOCKS, 0, 'w', "locks" },
#endif
#ifdef RLIMIT_NICE
{ RLIMIT_NICE, 0, 'e', "scheduling priority" },
#endif
#ifdef RLIMIT_RTPRIO
{ RLIMIT_RTPRIO, 0, 'r', "real-time priority" },
#endif
};
enum {
OPT_hard = (1 << 0),
OPT_soft = (1 << 1),
};
/* "-": treat args as parameters of option with ASCII code 1 */
static const char ulimit_opt_string[] = "-HSa"
#ifdef RLIMIT_FSIZE
"f::"
#endif
#ifdef RLIMIT_CPU
"t::"
#endif
#ifdef RLIMIT_DATA
"d::"
#endif
#ifdef RLIMIT_STACK
"s::"
#endif
#ifdef RLIMIT_CORE
"c::"
#endif
#ifdef RLIMIT_RSS
"m::"
#endif
#ifdef RLIMIT_MEMLOCK
"l::"
#endif
#ifdef RLIMIT_NPROC
"p::"
#endif
#ifdef RLIMIT_NOFILE
"n::"
#endif
#ifdef RLIMIT_AS
"v::"
#endif
#ifdef RLIMIT_LOCKS
"w::"
#endif
#ifdef RLIMIT_NICE
"e::"
#endif
#ifdef RLIMIT_RTPRIO
"r::"
#endif
;
static void printlim(unsigned opts, const struct rlimit *limit,
const struct limits *l)
{
rlim_t val;
val = limit->rlim_max;
if (!(opts & OPT_hard))
val = limit->rlim_cur;
if (val == RLIM_INFINITY)
printf("unlimited\n");
else {
val >>= l->factor_shift;
printf("%llu\n", (long long) val);
}
}
int FAST_FUNC
shell_builtin_ulimit(char **argv)
{
unsigned opts;
unsigned argc;
/* We can't use getopt32: need to handle commands like
* ulimit 123 -c2 -l 456
*/
/* In case getopt was already called:
* reset the libc getopt() function, which keeps internal state.
*/
#ifdef __GLIBC__
optind = 0;
#else /* BSD style */
optind = 1;
/* optreset = 1; */
#endif
/* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */
argc = 1;
while (argv[argc])
argc++;
opts = 0;
while (1) {
struct rlimit limit;
const struct limits *l;
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') {
for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
getrlimit(l->cmd, &limit);
printf("-%c: %-30s ", l->option, l->name);
printlim(opts, &limit, l);
}
continue;
}
if (opt_char == 1)
opt_char = 'f';
for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
if (opt_char == l->option) {
char *val_str;
getrlimit(l->cmd, &limit);
val_str = optarg;
if (!val_str && argv[optind] && argv[optind][0] != '-')
val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
if (val_str) {
rlim_t val;
if (strcmp(val_str, "unlimited") == 0)
val = RLIM_INFINITY;
else {
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 <<= l->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)
opts = OPT_hard + OPT_soft;
if (opts & OPT_hard)
limit.rlim_max = val;
if (opts & OPT_soft)
limit.rlim_cur = val;
//bb_error_msg("setrlimit(%d, %lld, %lld)", l->cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
if (setrlimit(l->cmd, &limit) < 0) {
bb_perror_msg("error setting limit");
return EXIT_FAILURE;
}
} else {
printlim(opts, &limit, l);
}
break;
}
} /* for (every possible opt) */
if (l == &limits_tbl[ARRAY_SIZE(limits_tbl)]) {
/* bad option. getopt already complained. */
break;
}
} /* while (there are options) */
return 0;
}