#!/usr/bin/perl
# chexec: turns a file's executability on or off, same semantics as rsync's --executability
# usage: chexec { + | - | --reference=<file> } <file> [...]
# Rename from setexec for consistency with chmod, etc. and cadaver's chexec - Matt 2009-07-02

$cmd = $ARGV[0];
shift @ARGV;

if ($cmd =~ /^--reference=(.*)$/) {
	$ref_file = $1;
	@stbuf = stat($ref_file);
	if (@stbuf == 0) {
		die "chexec: stat($ref_file): $!\n";
	}
	$ref_perms = $stbuf[2] & 07777;
	if (($ref_perms & 0111) == 0) {
		$cmd = '-';
	} else {
		$cmd = '+';
	}
} elsif ($cmd ne '+' && $cmd ne '-') {
	die "usage: chexec { + | - | --reference=<file> } <file> [...]\n";
}

sub docmd($$) {
	my ($cmd, $perms) = @_;
	if ($cmd eq '+') {
		return $perms | ($perms & 0444) >> 2;
	} elsif ($cmd eq '-') {
		return $perms & ~0111;
	}
}

file: foreach $file (@ARGV) {
	@stbuf = stat($file);
	if (@stbuf == 0) {
		warn "chexec: stat($file): $!, skipping file\n";
		next file;
	}
	$perms = $stbuf[2] & 07777;
	$perms = docmd($cmd, $perms);
	chmod($perms, $file) or warn "chexec: chmod($perms, $file): $!, skipping file\n";
}