1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <string.h>
#define CRONOLOG "/usr/sbin/cronolog"
char *pidfile;
void die(int sig) {
/* kill off children */
kill(0, SIGTERM);
/* remove pid file, quit */
unlink(pidfile);
exit(0);
}
struct sigaction sigdie = { .sa_handler = die };
int main(int argc, char *argv[]) {
time_t t = 0;
pid_t pid = 0;
int fd, pidfd, pidlen = 16;
char *fifo, *log, pidstr[16];
if (argc != 4) {
fprintf(stderr, "Usage: %s /path/to/pidfile /path/to/fifo"
" /path/to/logs/%%Y%%m%%d.log\n", argv[0]);
exit(1);
}
pidfile = argv[1];
fifo = argv[2];
log = argv[3];
/* Test for fifo access, leave open for use */
/* O_NONBLOCK allows us to fork into the background */
fd = open(fifo, O_RDONLY|O_NONBLOCK);
if (fd == -1) {
fprintf(stderr, "Cannot open fifo %s: %s\n", fifo, strerror(errno));
exit(1);
}
pid = fork();
if (pid == 0) {
/* CHILD 0 */
/* Record pid to pidfile */
pidfd = open(pidfile, O_WRONLY|O_CREAT|O_EXCL, 0644);
if (pidfd == -1) {
fprintf(stderr, "Cannot create and open pid file %s: %s\n",
pidfile, strerror(errno));
exit(1);
} else {
pidlen = snprintf(pidstr, pidlen, "%d\n", getpid());
write(pidfd, pidstr, pidlen);
close(pidfd);
}
/* close shell output */
close(0);
close(1);
close(2);
/* set a process group for easy cleanup */
setpgrp();
sigaction(SIGTERM, &sigdie, NULL);
/* keep the cronolog process open */
while (1) {
t = time(NULL);
pid = fork();
if (pid == 0) {
/* CHILD 1 */
/* replace stdin with fifo */
dup2(fd, 0);
/* unset O_NONBLOCK */
fcntl(0, F_SETFL, 0);
/* exec cronolog */
execl(CRONOLOG, CRONOLOG, log, (char *) 0);
/* filure! give up on life */
exit(1);
} else {
/* PARENT 1 */
/* watch child 1 */
waitpid(pid, NULL, 0);
if (time(NULL) - t < 2) {
/* restarting too fast, wait 10 seconds */
sleep(10);
}
}
}
}
/* PARENT 0 exits */
close(fd);
return 0;
}
|
GitWeb