+ my $fh = open_compressed_file('foo.gz') or
+ die "Unable to open compressed file: $!";
+
+
+Opens a file; if the file ends in .gz, .xz, or .bz2, the appropriate
+decompression program is forked and output from it is read.
+
+This routine by default opens the file with UTF-8 encoding; if you want some
+other encoding, specify it with the second option.
+
+=cut
+sub open_compressed_file {
+ my ($file,$encoding) = @_;
+ $encoding //= ':encoding(UTF-8)';
+ my $fh;
+ my $mode = "<$encoding";
+ my @opts;
+ if ($file =~ /\.gz$/) {
+ $mode = "-|$encoding";
+ push @opts,'gzip','-dc';
+ }
+ if ($file =~ /\.xz$/) {
+ $mode = "-|$encoding";
+ push @opts,'xz','-dc';
+ }
+ if ($file =~ /\.bz2$/) {
+ $mode = "-|$encoding";
+ push @opts,'bzip2','-dc';
+ }
+ open($fh,$mode,@opts,$file);
+ return $fh;
+}