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/* See LICENSE for licence details. */
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>
#include <stdlib.h>
int try_mkdir(const char *dn) {
int ret;
errno = 0;
ret = 0;
ret = mkdir(dn, S_IRUSR);
if(errno && errno != EEXIST) {
fprintf(stderr, "Failed to create lock %s.\n", dn);
exit(EXIT_FAILURE);
}
return ret;
}
int main(int argc, char **argv){
if(argc != 2){
fprintf(stderr, "Please supply one argument: the lock directory.\n");
return EXIT_FAILURE;
}
/* create lock */
if(try_mkdir(argv[1])){
/* lock exists */
for(; try_mkdir(argv[1]); ){
sleep(1);
}
}
return EXIT_SUCCESS;
}
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