dh_compress

   1 #!/usr/bin/perl -w
   2 #
   3 # Compresses files and makes sure that symlinks pointing to the
   4 # compressed files get fixed.
   5
   6 use Cwd;
   7 BEGIN { push @INC, "debian", "/usr/share/debhelper" }
   8 use Dh_Lib;
   9 init();
  10
  11 foreach $PACKAGE (@{$dh{DOPACKAGES}}) {
  12         $TMP=tmpdir($PACKAGE);
  13         $compress=pkgfile($PACKAGE,"compress");
  14
  15         # Run the file name gathering commands from within the directory
  16         # structure that will be effected.
  17         $olddir=getcwd();
  18         verbose_print("cd $TMP");
  19         chdir($TMP) || error("Can't cd to $TMP: $!");
  20
  21         # Figure out what files to compress.
  22         @files=();
  23         # First of all, deal with any files specified right on the command line.
  24         if (($PACKAGE eq $dh{FIRSTPACKAGE} || $dh{PARAMS_ALL}) && @ARGV) {
  25                 push @files, @ARGV;
  26         }
  27         if ($compress) {
  28                 # The config file is a sh script that outputs the files to be compressed
  29                 # (typically using find).
  30                 push @files, split(/\n/,`sh $olddir/$compress 2>/dev/null`);
  31         }
  32         else {
  33                 # By default, fall back to what the policy manual says to compress.
  34                 # Note that all the excludes of odd things like _z are because
  35                 # gzip refuses to compress such files, assumming they are zip files.
  36                 # I looked at the gzip source to get the complete list of such
  37                 # extentions: ".gz", ".z", ".taz", ".tgz", "-gz", "-z", "_z"
  38
  39                 push @files, split(/\n/,`
  40                         find usr/info usr/share/info usr/man usr/share/man usr/X11*/man -type f ! -name "*.gz" 2>/dev/null || true;
  41                         find usr/doc usr/share/doc -type f \\( -size +4k -or -name "changelog*" \\) \\
  42                                 \\( -name changelog.html -or ! -name "*.htm*" \\) \\
  43                                 ! -name "*.gif" ! -iname "*.gz" \\
  44                                 ! -iname "*.taz" ! -iname "*.tgz" ! -iname "*.z" \\
  45                                 ! -iname "*-gz" ! -iname "*-z" ! -iname "*_z" \\
  46                                 ! -name "copyright" 2>/dev/null || true
  47                 `);
  48         }
  49
  50         # Exclude files from compression.
  51         if (@files && defined($dh{EXCLUDE}) && $dh{EXCLUDE}) {
  52                 @new=();
  53                 foreach (@files) {
  54                         $ok=1;
  55                         foreach $x (@{$dh{EXCLUDE}}) {
  56                                 if (/\Q$x\E/) {
  57                                         $ok='';
  58                                         last;
  59                                 }
  60                         }
  61                         push @new,$_ if $ok;
  62                 }
  63                 @files=@new;
  64         }
  65
  66         # Look for files with hard links. If we are going to compress both,
  67         # we can preserve the hard link across the compression and save
  68         # space in the end.
  69         my @f=();
  70         my %hardlinks;
  71         foreach (@files) {
  72                 ($dev, $inode, undef, $nlink)=stat($_);
  73                 if ($nlink > 1) {
  74                         if (! $seen{"$inode.$dev"}) {
  75                                 $seen{"$inode.$dev"}=$_;
  76                                 push @f, $_;
  77                         }
  78                         else {
  79                                 # This is a hardlink.
  80                                 $hardlinks{$_}=$seen{"$inode.$dev"};
  81                         }
  82                 }
  83                 else {
  84                         push @f, $_;
  85                 }
  86         }
  87
  88         if (@f) {
  89                 xargs(\@f,"gzip","-9f");
  90         }
  91
  92         # Now change over any files we can that used to be hard links so
  93         # they are again.
  94         foreach (keys %hardlinks) {
  95                 # Remove old file.
  96                 doit("rm","-f","$_");
  97                 # Make new hardlink.
  98                 doit("ln","$hardlinks{$_}.gz","$_.gz");
  99         }
 100
 101         verbose_print("cd $olddir");
 102         chdir($olddir);
 103
 104         # Fix up symlinks that were pointing to the uncompressed files.
 105         open (FIND,"find $TMP -type l |");
 106         while (<FIND>) {
 107                 chomp;
 108                 ($directory)=m:(.*)/:;
 109                 $linkval=readlink($_);
 110                 if (! -e "$directory/$linkval" && -e "$directory/$linkval.gz") {
 111                         doit("rm","-f",$_);
 112                         doit("ln","-sf","$linkval.gz","$_.gz");
 113                 }
 114         }
 115 }