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/*
* This simple program tries to lock a file the same way dpkg (and
* apt) do. If it succeeds, it drops the lock and returns 0. If it fails,
* it returns > 0.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/file.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
static int methlockfd;
int main (int argc, char **argv) {
struct flock fl;
if (argc < 2) {
fprintf(stderr, "Must specify lock file to check.\n");
exit(100);
}
methlockfd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0660);
if (methlockfd == -1) {
exit(2);
}
fl.l_type= F_WRLCK;
fl.l_whence= SEEK_SET;
fl.l_start= 0;
fl.l_len= 0;
if (fcntl(methlockfd,F_SETLK,&fl) == -1) {
exit(1);
}
exit (0);
}
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