/* ulimit.c - Modify resource limits * * Copyright 2015 Rob Landley <rob@landley.net> * * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ulimit.html * And man prlimit(2). * * Deviations from posix: The units on -f are supposed to be 512 byte * "blocks" (no other options are specified, and even hard drives don't * do that anymore). Bash uses 1024 byte blocks, so they don't care either. * We consistently use bytes everywhere we can. * * Deviations from bash: Sizes are in bytes (instead of -p 512 and -f 1024). * Bash's -p value has been wrong since 2010 (git 35f3d14dbbc5). * The kernel implementation of RLIMIT_LOCKS (-x) was removed from Linux in * 2003. Bash never implemented -b (it's in the help but unrecognized at * runtime). We support -P to affect processes other than us. USE_ULIMIT(NEWTOY(ulimit, ">1P#<1SHavutsrRqpnmlifedc[-SH][!apvutsrRqnmlifedc]", TOYFLAG_USR|TOYFLAG_BIN)) USE_ULIMIT(OLDTOY(prlimit, ulimit, TOYFLAG_USR|TOYFLAG_BIN)) config ULIMIT bool "ulimit" default y depends on TOYBOX_PRLIMIT help usage: ulimit [-P PID] [-SHRacdefilmnpqrstuv] [LIMIT] Print or set resource limits for process number PID. If no LIMIT specified (or read-only -ap selected) display current value (sizes in bytes). Default is ulimit -P $PPID -Sf" (show soft filesize of your shell). -S Set/show soft limit -H Set/show hard (maximum) limit -a Show all limits -c Core file size -d Process data segment -e Max scheduling priority -f Output file size -i Pending signal count -l Locked memory -m Resident Set Size -n Number of open files -p Pipe buffer -q Posix message queue -r Max Real-time priority -R Realtime latency (usec) -s Stack size -t Total CPU time (in seconds) -u Maximum processes (under this UID) -v Virtual memory size -P PID to affect (default $PPID) */ #define FOR_ulimit #include "toys.h" GLOBALS( long P; ) // This is a linux kernel syscall added in 2.6.36 (git c022a0acad53) which // glibc only exports a wrapper prototype for if you #define _FSF_HURD_RULZE. int prlimit(pid_t pid, int resource, const struct rlimit *new_limit, struct rlimit *old_limit); // I'd like to sort the RLIMIT values 0-15, but mips, alpha and sparc // override the asm-generic values for 5-9. Also, the kernel implementation // of RLIMIT_LOCKS (-x) was removed from Linux in 2003. void ulimit_main(void) { struct rlimit rr; int i; // Order is cdefilmnqRrstuv char map[] = {RLIMIT_CORE, RLIMIT_DATA, RLIMIT_NICE, RLIMIT_FSIZE, RLIMIT_SIGPENDING, RLIMIT_MEMLOCK, RLIMIT_RSS, RLIMIT_NOFILE, 0, RLIMIT_MSGQUEUE, RLIMIT_RTTIME, RLIMIT_RTPRIO, RLIMIT_STACK, RLIMIT_CPU, RLIMIT_NPROC, RLIMIT_AS}; if (!(toys.optflags&(FLAG_H-1))) toys.optflags |= FLAG_f; if ((FLAG(a)||FLAG(p)) && toys.optc) error_exit("can't set -ap"); // Fetch data if (!FLAG(P)) TT.P = getppid(); for (i=0; i<sizeof(map); i++) { char *flags="cdefilmnpqRrstuv"; int get = toys.optflags&(FLAG_a|(1<<i)); if (get && prlimit(TT.P, map[i], 0, &rr)) perror_exit("-%c", flags[i]); if (!toys.optc) { if (FLAG(a)) printf("-%c: ", flags[i]); if (get) { if ((1<<i)&FLAG_p) { if (FLAG(H)) xreadfile("/proc/sys/fs/pipe-max-size", toybuf, sizeof(toybuf)); else { int pp[2]; xpipe(pp); sprintf(toybuf, "%d\n", fcntl(*pp, F_GETPIPE_SZ)); } printf("%s", toybuf); } else { rlim_t rl = FLAG(H) ? rr.rlim_max : rr.rlim_cur; if (rl == RLIM_INFINITY) printf("unlimited\n"); else printf("%ld\n", (long)rl); } } } if (toys.optflags&(1<<i)) break; } if (FLAG(a)||FLAG(p)) return; if (toys.optc) { rlim_t val; if (tolower(**toys.optargs) == 'u') val = RLIM_INFINITY; else val = atolx_range(*toys.optargs, 0, LONG_MAX); if (FLAG(H)) rr.rlim_max = val; else rr.rlim_cur = val; if (prlimit(TT.P, map[i], &rr, 0)) perror_exit(0); } }