MKLOCK prgrm to create lock file against concurrent accesses

[VanRietschote]

---
mklock will create a lock file which can be tested against to disallow
the concurrent access to a shared resource. It is simple but does the trick.
For more info see next news item with manual page.

Feel free to use or abuse this program at your own risk.

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/* mklock.c to create .lock file -*-update-version-*-
 * HFVR VERSION=Thu Apr 11 10:39:33 1985
 * Usage: mklock file
*/

#include <stdio.h>

main(argc,argv)
int argc;
char *argv[];
{
 int f;

 if (argc != 2) {
  fprintf(stderr,"\007%s: exactly one argument expected\n",argv[0]);
  exit(1);
 }/*fi*/
 if ((strcmp(argv[1],"-?") == 0)) {
  fprintf(stderr,"%s creates lock file. Usage: %s file.\n",argv[0],argv[0]);
  exit(1); 
 }/*fi*/
 if ((f = creat(argv[1],0)) < 0) {
  fprintf(stderr,"\007%s: ",argv[0]);
  perror(""); 
  exit(1);
 } else {
  close(f);
  exit(0);
 }/*fi*/
}