source: trunk/debathena/debathena/firefox-wrapper/testlock.c @ 22525

Revision 22525, 1.1 KB checked in by rbasch, 18 years ago (diff)
Open the lock file read-only, since we are not setting a lock. Also remove the extraneous mode parameter in the open().
Line 
1#include <stdio.h>
2#include <sys/types.h>
3#include <sys/stat.h>
4#include <unistd.h>
5#include <fcntl.h>
6#include <string.h>
7#include <errno.h>
8
9int main(int argc, char **argv)
10{
11  char *progname, *filename;
12  int fd;
13  struct flock lock;
14
15  progname = argv[0];
16  if (argc != 2)
17    {
18      fprintf(stderr, "%s: Usage: %s <lock_file>\n", progname, progname);
19      return 4;
20    }
21  filename = argv[1];
22
23  /* Open the file. */
24  fd = open(filename, O_RDONLY);
25  if (fd == -1)
26    {
27      fprintf(stderr, "%s: Cannot open %s: %s\n", progname, filename,
28              strerror(errno));
29      return 3;
30    }
31
32  /* See if there is a write lock on the file. */
33  lock.l_type = F_WRLCK;
34  lock.l_whence = SEEK_SET;
35  lock.l_start = 0;
36  lock.l_len = 0;
37  if (fcntl(fd, F_GETLK, &lock) == -1)
38    {
39      fprintf(stderr, "%s: Cannot get the lock for %s: %s\n", progname,
40              filename, strerror(errno));
41      return 3;
42    }
43  close(fd);
44  if (lock.l_type != F_UNLCK)
45    {
46      /* The file is locked; print the PID of the locking process. */
47      printf("%ld\n", (long) lock.l_pid);
48      return 2;
49    }
50  return 0;
51}
Note: See TracBrowser for help on using the repository browser.