util/copy-if-different.pl

   1 #!/usr/local/bin/perl
   2
   3 use strict;
   4
   5 use Fcntl;
   6
   7 # copy-if-different.pl
   8
   9 # Copy to the destination if the source is not the same as it.
  10
  11 my @filelist;
  12
  13 foreach my $arg (@ARGV) {
  14         $arg =~ s|\\|/|g;       # compensate for bug/feature in cygwin glob...
  15         foreach (glob $arg)
  16                 {
  17                 push @filelist, $_;
  18                 }
  19 }
  20
  21 my $fnum = @filelist;
  22
  23 if ($fnum <= 1)
  24         {
  25         die "Need at least two filenames";
  26         }
  27
  28 my $dest = pop @filelist;
  29
  30 if ($fnum > 2 && ! -d $dest)
  31         {
  32         die "Destination must be a directory";
  33         }
  34
  35 foreach (@filelist)
  36         {
  37         my $dfile;
  38         if (-d $dest)
  39                 {
  40                 $dfile = $_;
  41                 $dfile =~ s|^.*[/\\]([^/\\]*)$|$1|;
  42                 $dfile = "$dest/$dfile";
  43                 }
  44         else
  45                 {
  46                 $dfile = $dest;
  47                 }
  48
  49         my $buf;
  50         if (-f $dfile)
  51                 {
  52                 sysopen(IN, $_, O_RDONLY|O_BINARY) || die "Can't Open $_";
  53                 sysopen(OUT, $dfile, O_RDONLY|O_BINARY)
  54                   || die "Can't Open $dfile";
  55                 while (sysread IN, $buf, 10240)
  56                         {
  57                         my $b2;
  58                         goto copy if !sysread(OUT, $b2, 10240) || $buf ne $b2;
  59                         }
  60                 goto copy if sysread(OUT, $buf, 1);
  61                 close(IN);
  62                 close(OUT);
  63                 print "NOT copying: $_ to $dfile\n";
  64                 next;
  65                 }
  66       copy:
  67         sysopen(IN, $_, O_RDONLY|O_BINARY) || die "Can't Open $_";
  68         sysopen(OUT, $dfile, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY)
  69                                         || die "Can't Open $dfile";
  70         while (sysread IN, $buf, 10240)
  71                 {
  72                 syswrite(OUT, $buf, length($buf));
  73                 }
  74         close(IN);
  75         close(OUT);
  76         print "Copying: $_ to $dfile\n";
  77         }
  78