listGroups

#!/usr/bin/env perl -w
#
# grouplist
#
# 2007-12-14: From function in .utilities, by Steven J. DeRose.
# 2012-09-12: ??
# 2015-09-17: Fix help, add -q and -v.
#
# To do:
#
use strict;
use Getopt::Long;

our $VERSION_DATE = "2015-09-17";

my $quiet   = 0;
my $verbose = 0;

# Process options
#
Getopt::Long::Configure ("ignore_case");
my $result = GetOptions(
    "h|help|?"          => sub { system "perldoc $0"; exit; },
    "q|quiet!"          => \$quiet,
    "v|verbose+"        => \$verbose,
    "version"           => sub {
        die "Version of $VERSION_DATE, by Steven J. DeRose.\n";
    }
    );
($result) || die "Bad options.\n";


###############################################################################
###############################################################################
# Main
#
my $col = $ENV{COLUMNS};
if ($col == 0) { $col = 79; }

my $cmd = "cat /etc/group | grep -v '^#'";

if (scanlar(@ARGV) eq 0) {
    $cmd .= " | sed 's/:.*\$//'";
    if ($quiet) {
        $cmd .= " | grep -v '^_'";
    }
    $cmd .= " | sort"
        . " | wrap -width $col -rpad 20";
}
else {
    $cmd .= " | grep \'^$ARGV[0]:'"
        . " | cut -d ':' -f 4-"
        . " | tr ',' '\012'"
        . " | sort"
        . " | wrap -width $col -rpad 20";
}

if ($verbose) {
    warn "Running:\n    $cmd\n";
}
system $cmd;

exit;


###############################################################################
###############################################################################

=pod

=head1 Usage

    listGroups [options] [file]

With no argument, show list of all *nix groups legibly.
With an argument, show members of that group.

Just runs a pipe.


=head1 Options

=over

=item * B<--quiet> OR B<-q>
Suppress most messages, and all groups beginning with '_'.

=item * B<--verbose> OR B<-v>
Add more detailed messages.

=item * B<--version>

Display version info and exit.

=back


=head1 Ownership

This work by Steven J. DeRose is licensed under a Creative Commons
Attribution-Share Alike 3.0 Unported License. For further information on
this license, see L<here|"http://creativecommons.org/licenses/by-sa/3.0/">.

For the most recent version, see L<here|"http://www.derose.net/steve/utilities/">.

=cut