src/suffix.c

   1 /* This file is part of GNU tar.
   2    Copyright (C) 2007, 2009 Free Software Foundation, Inc.
   3
   4    Written by Sergey Poznyakoff.
   5
   6    GNU tar is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 3, or (at your option) any later
   9    version.
  10
  11    GNU tar is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
  14    Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License along
  17    with GNU tar.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include <system.h>
  20 #include "common.h"
  21
  22 struct compression_suffix
  23 {
  24   const char *suffix;
  25   size_t length;
  26   const char *program;
  27 };
  28
  29 static struct compression_suffix compression_suffixes[] = {
  30 #define __CAT2__(a,b) a ## b
  31 #define S(s,p) #s, sizeof (#s) - 1, __CAT2__(p,_PROGRAM)
  32   { S(gz,   GZIP) },
  33   { S(tgz,  GZIP) },
  34   { S(taz,  GZIP) },
  35   { S(Z,    COMPRESS) },
  36   { S(taZ,  COMPRESS) },
  37   { S(bz2,  BZIP2) },
  38   { S(tbz,  BZIP2) },
  39   { S(tbz2, BZIP2) },
  40   { S(tz2,  BZIP2) },
  41   { S(lzma, LZMA) },
  42   { S(tlz,  LZMA) },
  43   { S(lzo,  LZOP) },
  44   { S(xz,   XZ) },
  45 #undef S
  46 #undef __CAT2__
  47 };
  48
  49 static int nsuffixes = sizeof (compression_suffixes) /
  50                         sizeof (compression_suffixes[0]);
  51
  52 static const char *
  53 find_compression_program (const char *name, const char *defprog)
  54 {
  55   char *suf = strrchr (name, '.');
  56
  57   if (suf)
  58     {
  59       int i;
  60       size_t len;
  61
  62       suf++;
  63       len = strlen (suf);
  64
  65       for (i = 0; i < nsuffixes; i++)
  66         {
  67           if (compression_suffixes[i].length == len
  68               && memcmp (compression_suffixes[i].suffix, suf, len) == 0)
  69             return compression_suffixes[i].program;
  70         }
  71     }
  72   return defprog;
  73 }
  74
  75 void
  76 set_comression_program_by_suffix (const char *name, const char *defprog)
  77 {
  78   const char *program = find_compression_program (name, defprog);
  79   if (program)
  80     use_compress_program_option = program;
  81 }
  82