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DEFINITIONS
This source file includes following definitions.
- usage
- sig_alrm_kill
- sig_alrm_term
- sig_term
- sig_usr1
- new_process_group
- main
1 /* run a command with a limited timeout
2 tridge@samba.org, June 2005
3 metze@samba.org, March 2006
4
5 attempt to be as portable as possible (fighting posix all the way)
6 */
7 #include <stdio.h>
8 #include <string.h>
9 #include <stdlib.h>
10 #include <unistd.h>
11 #include <signal.h>
12 #include <errno.h>
13 #include <sys/types.h>
14 #include <sys/wait.h>
15
16 static pid_t child_pid;
17
18 static void usage(void)
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19 {
20 printf("usage: timelimit <time> <command>\n");
21 printf(" SIGUSR1 - passes SIGTERM to command's process group\n");
22 printf(" SIGALRM - passes SIGTERM to command's process group\n");
23 printf(" after 5s SIGKILL will be passed and exit(1)\n");
24 printf(" SIGTERM - passes SIGTERM to command's process group\n");
25 printf(" after 1s SIGKILL will be passed and exit(1)\n");
26 }
27
28 static void sig_alrm_kill(int sig)
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29 {
30 fprintf(stderr, "\nMaximum time expired in timelimit - killing\n");
31 kill(-child_pid, SIGKILL);
32 exit(1);
33 }
34
35 static void sig_alrm_term(int sig)
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36 {
37 kill(-child_pid, SIGTERM);
38 alarm(5);
39 signal(SIGALRM, sig_alrm_kill);
40 }
41
42 static void sig_term(int sig)
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43 {
44 kill(-child_pid, SIGTERM);
45 alarm(1);
46 signal(SIGALRM, sig_alrm_kill);
47 }
48
49 static void sig_usr1(int sig)
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50 {
51 kill(-child_pid, SIGTERM);
52 }
53
54 static void new_process_group(void)
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55 {
56 if (setpgid(0,0) == -1) {
57 perror("setpgid");
58 exit(1);
59 }
60 }
61
62
63 int main(int argc, char *argv[])
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64 {
65 int maxtime, ret=1;
66
67 if (argc < 3) {
68 usage();
69 exit(1);
70 }
71
72 maxtime = atoi(argv[1]);
73
74 child_pid = fork();
75 if (child_pid == 0) {
76 new_process_group();
77 execvp(argv[2], argv+2);
78 perror(argv[2]);
79 exit(1);
80 }
81
82 signal(SIGTERM, sig_term);
83 signal(SIGINT, sig_term);
84 signal(SIGQUIT, sig_term);
85 signal(SIGUSR1, sig_usr1);
86 signal(SIGALRM, sig_alrm_term);
87 alarm(maxtime);
88
89 do {
90 int status;
91 pid_t pid = wait(&status);
92 if (pid != -1) {
93 ret = WEXITSTATUS(status);
94 } else if (errno == ECHILD) {
95 break;
96 }
97 } while (1);
98
99 kill(-child_pid, SIGKILL);
100
101 exit(ret);
102 }