Dogcows Code - chaz/tar/blob - tests/mksparse.c

   1 /* This file is part of GNU tar test suite
   2
   3    Copyright (C) 2004 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by the
   7    Free Software Foundation; either version 2, or (at your option) any later
   8    version.
   9
  10    This program is distributed in the hope that it will be useful, but
  11    WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
  13    Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License along
  16    with this program; if not, write to the Free Software Foundation, Inc.,
  17    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include <config.h>
  21 #endif
  22 #include <unistd.h>
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <stdarg.h>
  26 #include <fcntl.h>
  27 #include <string.h>
  28
  29 char *progname;
  30 char *buffer;
  31 size_t buffer_size;
  32
  33 void
  34 die (char *fmt, ...)
  35 {
  36   va_list ap;
  37
  38   fprintf (stderr, "%s: ", progname);
  39   va_start (ap, fmt);
  40   vfprintf (stderr, fmt, ap);
  41   va_end (ap);
  42   fprintf (stderr, "\n");
  43 }
  44
  45 void
  46 mkhole (int fd, off_t displ)
  47 {
  48   if (displ = lseek (fd, displ, SEEK_CUR) == -1)
  49     {
  50       perror ("lseek");
  51       exit (1);
  52     }
  53   ftruncate (fd, lseek (fd, 0, SEEK_CUR));
  54 }
  55
  56 void
  57 mksparse (int fd, off_t displ, char *marks)
  58 {
  59   int i;
  60
  61   for (; *marks; marks++)
  62     {
  63       memset (buffer, *marks, buffer_size);
  64       if (write(fd, buffer, buffer_size) != buffer_size)
  65         {
  66           perror ("write");
  67           exit (1);
  68         }
  69
  70       if (lseek (fd, displ, SEEK_CUR) == -1)
  71         {
  72           perror ("lseek");
  73           exit (1);
  74         }
  75     }
  76 }
  77
  78 void
  79 usage ()
  80 {
  81   printf ("Usage: mksparse filename blocksize disp letters [disp letters...] [disp]\n");
  82   exit (1);
  83 }
  84
  85 int
  86 xlat_suffix (off_t *vp, char *p)
  87 {
  88   if (p[1])
  89     return 1;
  90   switch (p[0])
  91     {
  92     case 'g':
  93     case 'G':
  94       *vp *= 1024;
  95
  96     case 'm':
  97     case 'M':
  98       *vp *= 1024;
  99
 100     case 'k':
 101     case 'K':
 102       *vp *= 1024;
 103       break;
 104
 105     default:
 106       return 1;
 107     }
 108   return 0;
 109 }
 110
 111 int
 112 main (int argc, char **argv)
 113 {
 114   int i;
 115   int fd;
 116   char *p;
 117   off_t n;
 118
 119   progname = strrchr (argv[0], '/');
 120   if (progname)
 121     progname++;
 122   else
 123     progname = argv[0];
 124
 125   if (argc < 4)
 126     usage ();
 127
 128   fd = open (argv[1], O_CREAT|O_TRUNC|O_RDWR, 0644);
 129   if (fd < 0)
 130     die ("cannot open %s", argv[1]);
 131
 132   n = strtoul (argv[2], &p, 0);
 133   if (n <= 0 || (*p && xlat_suffix (&n, p)))
 134     die ("Invalid buffer size: %s", argv[2]);
 135   buffer_size = n;
 136   buffer = malloc (buffer_size);
 137   if (!buffer)
 138     die ("Not enough memory");
 139
 140   for (i = 3; i < argc; i += 2)
 141     {
 142       off_t displ;
 143
 144       displ = strtoul (argv[i], &p, 0);
 145       if (displ < 0 || (*p && xlat_suffix (&displ, p)))
 146         die ("Invalid displacement: %s", argv[i]);
 147
 148       if (i == argc-1)
 149         {
 150           mkhole (fd, displ);
 151           break;
 152         }
 153       else
 154         mksparse (fd, displ, argv[i+1]);
 155     }
 156
 157   close(fd);
 158   return 0;
 159 }