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 static void die (char const *, ...) __attribute__ ((noreturn,
  34                                                     format (printf, 1, 2)));
  35 static void
  36 die (char const *fmt, ...)
  37 {
  38   va_list ap;
  39
  40   fprintf (stderr, "%s: ", progname);
  41   va_start (ap, fmt);
  42   vfprintf (stderr, fmt, ap);
  43   va_end (ap);
  44   fprintf (stderr, "\n");
  45   exit (1);
  46 }
  47
  48 static void
  49 mkhole (int fd, off_t displ)
  50 {
  51   if (lseek (fd, displ, SEEK_CUR) == -1)
  52     {
  53       perror ("lseek");
  54       exit (1);
  55     }
  56   ftruncate (fd, lseek (fd, 0, SEEK_CUR));
  57 }
  58
  59 static void
  60 mksparse (int fd, off_t displ, char *marks)
  61 {
  62   for (; *marks; marks++)
  63     {
  64       memset (buffer, *marks, buffer_size);
  65       if (write(fd, buffer, buffer_size) != buffer_size)
  66         {
  67           perror ("write");
  68           exit (1);
  69         }
  70
  71       if (lseek (fd, displ, SEEK_CUR) == -1)
  72         {
  73           perror ("lseek");
  74           exit (1);
  75         }
  76     }
  77 }
  78
  79 static void usage (void) __attribute__ ((noreturn));
  80 static void
  81 usage (void)
  82 {
  83   printf ("Usage: mksparse filename blocksize disp letters [disp letters...] [disp]\n");
  84   exit (1);
  85 }
  86
  87 static int
  88 xlat_suffix (off_t *vp, char *p)
  89 {
  90   if (p[1])
  91     return 1;
  92   switch (p[0])
  93     {
  94     case 'g':
  95     case 'G':
  96       *vp *= 1024;
  97
  98     case 'm':
  99     case 'M':
 100       *vp *= 1024;
 101
 102     case 'k':
 103     case 'K':
 104       *vp *= 1024;
 105       break;
 106
 107     default:
 108       return 1;
 109     }
 110   return 0;
 111 }
 112
 113 int
 114 main (int argc, char **argv)
 115 {
 116   int i;
 117   int fd;
 118   char *p;
 119   off_t n;
 120
 121   progname = strrchr (argv[0], '/');
 122   if (progname)
 123     progname++;
 124   else
 125     progname = argv[0];
 126
 127   if (argc < 4)
 128     usage ();
 129
 130   fd = open (argv[1], O_CREAT|O_TRUNC|O_RDWR, 0644);
 131   if (fd < 0)
 132     die ("cannot open %s", argv[1]);
 133
 134   n = strtoul (argv[2], &p, 0);
 135   if (n <= 0 || (*p && xlat_suffix (&n, p)))
 136     die ("Invalid buffer size: %s", argv[2]);
 137   buffer_size = n;
 138   buffer = malloc (buffer_size);
 139   if (!buffer)
 140     die ("Not enough memory");
 141
 142   for (i = 3; i < argc; i += 2)
 143     {
 144       off_t displ;
 145
 146       displ = strtoul (argv[i], &p, 0);
 147       if (displ < 0 || (*p && xlat_suffix (&displ, p)))
 148         die ("Invalid displacement: %s", argv[i]);
 149
 150       if (i == argc-1)
 151         {
 152           mkhole (fd, displ);
 153           break;
 154         }
 155       else
 156         mksparse (fd, displ, argv[i+1]);
 157     }
 158
 159   close(fd);
 160   return 0;
 161 }