src/ftrunc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2003 Silicon Graphics, Inc.
   4  * All Rights Reserved.
   5  */
   6
   7 #include <unistd.h>
   8 #include <sys/types.h>
   9 #include <sys/stat.h>
  10 #include <fcntl.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14
  15 int
  16 main(argc, argv)
  17 int     argc;
  18 char    **argv;
  19
  20 {
  21 char *filename="testfile";
  22 int c;
  23 int fd, err;
  24
  25 if(argc != 3)
  26         {        printf("Usage: cxfs_ftrunc -f filename\n");
  27                 exit(1);
  28         }
  29
  30 while((c=getopt(argc,argv,"f:"))!=EOF) {
  31                 switch (c) {
  32                 case 'f':
  33                         filename = optarg;
  34                         break;
  35                 default:
  36                         fprintf(stderr,"Usage: ftrunc -f filename\n");
  37                         exit(1);
  38                 }
  39         }
  40
  41
  42
  43
  44           /* open RDWR but with read-only perms */
  45           fd = open(filename, O_CREAT|O_RDWR, 0400);
  46           if (fd < 0) {
  47                 perror("open failed");
  48                 return 1;
  49                 }
  50
  51           err = ftruncate(fd, 1000);
  52           if (err < 0) {
  53               perror("ftruncate failed");
  54               return 1;
  55            }
  56
  57           err = unlink(filename);
  58           if (err < 0) {
  59                 perror("unlink failed");
  60                 return 1;
  61           }
  62
  63           return 0;
  64
  65 }