bin/z: Add working utility

Pilfer initial version of manpage from zrun.

1 files changed, 153 insertions, 0 deletions

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+#!/usr/bin/env perl
+
+use v5.34;
+use warnings;
+use feature 'signatures';
+no warnings qw(experimental::signatures);
+use Getopt::Std ();
+use File::Temp ();
+use File::Basename ();
+use List::Util qw(any);
+
+
+sub usage($fh) {
+	print $fh <<~'EOF'
+		Usage:
+		  z COMMANDS...
+		  z -h
+		EOF
+}
+
+sub help($fh) {
+	print $fh <<~'EOF'
+
+
+		Options:
+		  -h, --help    show this message
+
+
+		Wrapper that uncompresses file arguments to commands.
+		This enables having commands that operate on plain files to not
+		need to know if they're compressed or not.
+
+		It doesn't depend on the file extension, but on what file(1) says
+		of it.
+
+
+		Examples:
+
+		  Replacement for zcat(1p):
+
+		    $ z cat a-file.gz
+
+
+		  Transparent grep (where my-file.dat is xz compressed):
+
+		    $ z grep -E '[a-z]+' my-file.dat
+		EOF
+}
+
+for (@ARGV) {
+	last if $_ eq '--';
+	if ($_ eq '--help') {
+		usage *STDOUT;
+		help *STDOUT;
+		exit;
+	}
+}
+
+my %opts;
+if (!Getopt::Std::getopts('h', \%opts)) {
+	usage *STDERR;
+	exit 2;
+}
+
+if ($opts{h}) {
+	usage *STDOUT;
+	help *STDOUT;
+	exit;
+}
+
+
+# Transform
+#   FILENAME: content/type; charset=some\n
+# into
+#   content/type
+sub trim($x) {
+	chomp $x;
+	$x =~ s/^.*?: //;
+	$x =~ s/;.*$//;
+	return $x;
+}
+
+my %TYPES = (
+	'application/gzip'    => [qw(gzip -dc)],
+	'application/x-bzip2' => [qw(bzip2 -dc)],
+	'application/x-xz'    => [qw(xz -dc)],
+	'application/x-lzma'  => [qw(lzma -dc)],
+);
+
+my @tmpfiles;
+sub arg_for($arg) {
+	if (! -e $arg) {
+		return $arg;
+	}
+
+	my $type = trim `file -i $_`;
+	if (any { $type eq $_ } keys %TYPES) {
+		my $template = File::Basename::basename $arg . '.XXXXXX';
+		my ($fh, $tmpname) = File::Temp::tempfile(TEMPLATE => $template);
+		push @tmpfiles, $tmpname;
+		my @command = @{$TYPES{$type}};
+		print $fh `@command $arg`;
+		die $! if $?;
+		close $fh;
+		return $tmpname;
+	}
+
+	return $arg;
+}
+
+sub status_for($n) {
+	if ($n == -1) {
+		return 127;
+	} elsif ($n & 127) {
+		return $n & 127;
+	} else {
+		return $n >> 8;
+	}
+}
+
+my @CMD = map { arg_for $_ } @ARGV;
+exit status_for(system @CMD);
+
+END {
+	unlink @tmpfiles;
+}
+
+
+__END__
+
+=head1 NAME
+
+z - Wrapper that uncompresses file arguments to commands.
+
+=head1 SYNOPSIS
+
+z COMMAND FILE...
+
+=head1 DESCRIPTION
+
+Prefixing a shell command with "zrun" causes any compressed files that are
+arguments of the command to be transparently uncompressed to temp files
+(not pipes) and the uncompressed files fed to the command.
+
+This is a quick way to run a command that does not itself support
+compressed files, without manually uncompressing the files.
+
+The following compression types are supported: gz bz2 Z xz lzma lzo
+
+If zrun is linked to some name beginning with z, like zprog, and the link is
+executed, this is equivalent to executing "zrun prog".
+
+=cut