Convert X bitmaps (.xbm) to PNG - example of Pozkanzer tools

Poskanzer's bitmap / pixmap tools have been around for nearly twenty years. They go under names such as xbmtopbm or pnmtopng. Each tool converts one or other kind of file into another format. The tools are still useful today, after twenty years.

The following script converts xbm (X Windows bitmap) format files into png (Portable Network Graphics).

One gotcha is that anytopnm fails to detect xbm files correctly, so this uses xbmtopbm followed by anytopnm to do the conversions, finishing with pnmtopng.

#!/usr/bin/perl
use warnings;
use strict;
opendir (DIR,".");
my @files = readdir (DIR);
closedir (DIR);
my @xbmfiles = grep /.xbm$/, @files;
print "@xbmfiles\n";
foreach my $file (@xbmfiles) {
    my $outputfile = $file;
    $outputfile =~ s/.xbm/.png/ or die "Bad file name '$file'";
    system ("xbmtopbm  $outputfile");
}