src/extract-magic

   1 #!/usr/bin/perl -w
   2 # Derive #define directives from specially formatted `case ...:' statements.
   3
   4 # Copyright (C) 2003, 2005 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 use strict;
  20
  21 use Getopt::Long;
  22
  23 (my $VERSION = '$Revision: 1.5 $ ') =~ tr/[0-9].//cd;
  24 (my $ME = $0) =~ s|.*/||;
  25
  26 END
  27 {
  28   # Nobody ever checks the status of print()s.  That's okay, because
  29   # if any do fail, we're guaranteed to get an indicator when we close()
  30   # the filehandle.
  31   #
  32   # Close stdout now, and if there were no errors, return happy status.
  33   # If stdout has already been closed by the script, though, do nothing.
  34   defined fileno STDOUT
  35     or return;
  36   close STDOUT
  37     and return;
  38
  39   # Errors closing stdout.  Indicate that, and hope stderr is OK.
  40   warn "$ME: closing standard output: $!\n";
  41
  42   # Don't be so arrogant as to assume that we're the first END handler
  43   # defined, and thus the last one invoked.  There may be others yet
  44   # to come.  $? will be passed on to them, and to the final _exit().
  45   #
  46   # If it isn't already an error, make it one (and if it _is_ an error,
  47   # preserve the value: it might be important).
  48   $? ||= 1;
  49 }
  50
  51 sub usage ($)
  52 {
  53   my ($exit_code) = @_;
  54   my $STREAM = ($exit_code == 0 ? *STDOUT : *STDERR);
  55   if ($exit_code != 0)
  56     {
  57       print $STREAM "Try `$ME --help' for more information.\n";
  58     }
  59   else
  60     {
  61       print $STREAM <<EOF;
  62 Usage: $ME [OPTIONS] FILE
  63
  64 FIXME: describe
  65
  66 OPTIONS:
  67
  68   Derive #define directives from specially formatted `case ...:' statements.
  69
  70    --help             display this help and exit
  71    --version          output version information and exit
  72
  73 EOF
  74     }
  75   exit $exit_code;
  76 }
  77
  78 {
  79   GetOptions
  80     (
  81      help => sub { usage 0 },
  82      version => sub { print "$ME version $VERSION\n"; exit },
  83     ) or usage 1;
  84
  85   my $fail = 0;
  86
  87   @ARGV < 1
  88     and (warn "$ME: missing FILE arguments\n"), $fail = 1;
  89   1 < @ARGV
  90     and (warn "$ME: too many arguments\n"), $fail = 1;
  91   $fail
  92     and usage 1;
  93
  94   my $file = $ARGV[0];
  95
  96   open FH, $file
  97     or die "$ME: can't open `$file' for reading: $!\n";
  98
  99   # For each line like this:
 100   #   case S_MAGIC_ROMFS: /* 0x7275 */
 101   # emit one like this:
 102   #   # define S_MAGIC_ROMFS 0x7275
 103   # Fail if there is a `case S_MAGIC_.*' line without
 104   # a properly formed comment.
 105
 106   print <<EOF;
 107 /* Define the magic numbers as given by statfs(2).
 108    Please send additions to bug-coreutils\@gnu.org and meskes\@debian.org.
 109    This file is generated automatically from $file. */
 110
 111 #if defined __linux__
 112 EOF
 113
 114   while (defined (my $line = <FH>))
 115     {
 116       $line =~ /^[ \t]+case S_MAGIC_/
 117         or next;
 118       $line =~ m!^[ \t]+case (S_MAGIC_\w+): /\* (0x[0-9A-Fa-f]+) \*/$!
 119         or (warn "$ME:$file:$.: malformed case S_MAGIC_... line"),
 120           $fail = 1, next;
 121       my $name = $1;
 122       my $value = $2;
 123       print "# define $name $value\n";
 124     }
 125
 126   print <<\EOF;
 127 #elif defined __GNU__
 128 # include <hurd/hurd_types.h>
 129 #endif
 130 EOF
 131   close FH;
 132
 133   exit $fail;
 134 }