minix/lib/libc/sys/flock.c

   1 /* Library routines
   2  *
   3  * Porting to Minix 2.0.0
   4  * Author:      Giovanni Falzoni <gfalzoni@pointest.com>
   5  */
   6
   7 #include <sys/cdefs.h>
   8 #include "namespace.h"
   9 #include <lib.h>
  10
  11 #include <sys/types.h>
  12 #include <fcntl.h>
  13 #include <string.h>
  14 #include <errno.h>
  15 #include <unistd.h>
  16
  17 /*
  18  *      Name:           int flock(int fd, int mode);
  19  *      Function:       Implements the flock function in Minix.
  20  */
  21 int flock(int fd, int mode)
  22 {
  23   struct flock lck;
  24
  25   memset((void *) &lck, 0, sizeof(struct flock));
  26   switch (mode & ~LOCK_NB) {
  27   case LOCK_SH: lck.l_type = F_RDLCK; break;
  28   case LOCK_EX: lck.l_type = F_WRLCK; break;
  29   case LOCK_UN: lck.l_type = F_UNLCK; break;
  30   default: errno = EINVAL; return -1;
  31   }
  32   return fcntl(fd, mode & LOCK_NB ? F_SETLK : F_SETLKW, &lck);
  33 }
  34
  35 /** flock.c **/