init/cmd/killall5.c

87 lines
1.4 KiB
C

/* SPDX-License-Identifier: ISC */
#include <sys/types.h>
#include <dirent.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include "util.h"
static NORETURN void usage_and_exit(void)
{
fputs("Usage: killall5 SIGNAL\n", stderr);
exit(EXIT_FAILURE);
}
int main(int argc, char **argv)
{
int signo, ret = EXIT_SUCCESS;
pid_t pid, mypid, mysid;
struct dirent *ent;
const char *ptr;
DIR *dir;
if (argc != 2)
usage_and_exit();
ptr = argv[1];
if (*ptr == '-')
++ptr;
if (!isdigit(*ptr))
usage_and_exit();
for (signo = 0; isdigit(*ptr); ++ptr)
signo = signo * 10 + ((*ptr) - '0');
if (*ptr != '\0' || signo < 1 || signo > 31)
usage_and_exit();
kill(-1, SIGSTOP);
dir = opendir("/proc");
if (dir == NULL) {
perror("opendir /proc");
ret = EXIT_FAILURE;
goto out;
}
mypid = getpid();
mysid = getsid(0);
for (;;) {
errno = 0;
ent = readdir(dir);
if (ent == NULL) {
if (errno) {
perror("readdir");
ret = EXIT_FAILURE;
}
break;
}
if (!isdigit(ent->d_name[0]))
continue;
for (pid = 0, ptr = ent->d_name; isdigit(*ptr); ++ptr)
pid = pid * 10 + ((*ptr) - '0');
if (*ptr != '\0' || pid == mypid || getsid(pid) == mysid)
continue;
if (kill(pid, signo)) {
ret = EXIT_FAILURE;
fprintf(stderr, "kill %d: %s\n",
(int)pid, strerror(errno));
}
}
out:
kill(-1, SIGCONT);
return ret;
}