int
main(int argc, char *argv[])
{
struct rlimit rl;
int j;
pid_t childPid;
if (argc < 2 || argc > 3 || strcmp(argv[1], "--help") == 0)
usageErr("%s soft-limit [hard-limit]\n", argv[0]);
printRlimit("Initial maximum process limits: ", RLIMIT_NPROC);
/* Set new process limits (hard == soft if not specified) */
rl.rlim_cur = (argv[1][0] == 'i') ? RLIM_INFINITY :
getInt(argv[1], 0, "soft-limit");
rl.rlim_max = (argc == 2) ? rl.rlim_cur :
(argv[2][0] == 'i') ? RLIM_INFINITY :
getInt(argv[2], 0, "hard-limit");
if (setrlimit(RLIMIT_NPROC, &rl) == -1)
errExit("setrlimit");
printRlimit("New maximum process limits: ", RLIMIT_NPROC);
/* Create as many children as possible */
for (j = 1; ; j++) {
switch (childPid = fork()) {
case -1: errExit("fork");
case 0: _exit(EXIT_SUCCESS); /* Child */
default: /* Parent: display message about each new child
and let the resulting zombies accumulate */
printf("Child %d (PID=%ld) started\n", j, (long) childPid);
break;
}
}
}
// RLIMIT_AS Process virtual memory size (bytes)
// RLIMIT_CORE Core file size (bytes)
// RLIMIT_CPU CPU time (seconds)
// RLIMIT_DATA Process data segment (bytes)
// RLIMIT_FSIZE File size (bytes)
// RLIMIT_MEMLOCK Locked memory (bytes)
// RLIMIT_MSGQUEUE Bytes allocated for POSIX message queues for real user ID
// RLIMIT_NICE Nice value (since Linux 2.6.12)
// RLIMIT_NOFILE Maximum file descriptor number plus one
// RLIMIT_NPROC Number of processes for real user ID
// RLIMIT_RSS Resident set size (bytes; not implemented)
// RLIMIT_RTPRIO Realtime scheduling priority (since Linux 2.6.12)
// RLIMIT_RTTIME Realtime CPU time (microseconds; since Linux 2.6.25)
// RLIMIT_SIGPENDING Number of queued signals for real user ID (since
// RLIMIT_STACK Size of stack segment (bytes)
int main(int argc, char *argv[])
{
int selection;
int soft;
int resource;
struct rlimit limit;
if (argc < 3 && strcmp(argv[1], "--help") == 0) {
usageErr("%s resource-number soft-limit\n");
}
selection = getLong(argv[1], 0, "selection");
soft = getLong(argv[2], 0, "soft");
limit.rlim_cur = soft;
limit.rlim_max = soft;
switch (selection) {
case 1:
resource = RLIMIT_AS;
break;
case 2:
resource = RLIMIT_CORE;
break;
case 3:
resource = RLIMIT_CPU;
break;
case 4:
resource = RLIMIT_DATA;
break;
case 5:
resource = RLIMIT_FSIZE;
break;
case 6:
resource = RLIMIT_MEMLOCK;
break;
case 7:
resource = RLIMIT_MSGQUEUE;
break;
case 8:
resource = RLIMIT_NICE;
break;
case 9:
resource = RLIMIT_NOFILE;
break;
case 10:
resource = RLIMIT_NPROC;
break;
case 11:
resource = RLIMIT_RSS;
break;
case 12:
resource = RLIMIT_RTPRIO;
break;
case 13:
resource = RLIMIT_RTTIME;
break;
case 14:
resource = RLIMIT_SIGPENDING;
break;
case 15:
resource = RLIMIT_STACK;
break;
default:
usageErr("Invalid resource number\n");
}
printRlimit("BEFORE LIMIT: ", resource);
if (setrlimit(resource, &limit) == -1) {
errExit("setrlimit");
}
printRlimit("AFTER LIMIT: ", resource);
exit(EXIT_SUCCESS);
}
