//file : lock.c
＃i nclude unistd.h>
＃i nclude stdlib.h>
＃i nclude stdio.h>
＃i nclude fcntl.h>
＃i nclude errno.h>
int main()
{
int file_desc;
int save_errno;
file_desc = open("/tmp/LockFile.test", O_RDWR | O_CREAT | O_EXCL, 0444);
if (file_desc 0)
{
save_errno = errno;
printf("Open failed with error is %d\n", save_errno);
}
else {
printf("Open succeeded\n");
}
exit(EXIT_SUCCESS);
}