#!/usr/bin/env perl
# ds
# Created Fri Oct 22 2004 by dwm@austin.ibm.com
# $Id: ds,v 1.11 2004/11/05 23:24:06 dwm Exp $

require 5.6.1;
use Getopt::Long 2.33;
use Pod::Usage;
use Data::Dumper;
use Config;


### variables and subroutines ##
$opt_debug = 0;
$opt_help = 0;
$opt_man = 0;

$stat_flags = "";
$diff_flags = "-Nwupa";
@dirs = ();
@tops = ();

sub infer_orig ( $ ) {
    my $suf = "$_[0]\$";
    my $x = $ENV{PWD};
    my $basedir;
    ($basedir = $x) =~ s,.*/,,;
    if ($basedir =~ m{$suf}) {
        ($tops[0] = $basedir) =~ s{$suf}{};
	$tops[1] = $basedir;
	return 1;
    }
    return 0;
}


#############  main  ####################
GetOptions (
            'debug'       => \$opt_debug,
            'diffflags=s' => \$diff_flags,
            'dirs=s'      => \@dirs,
            'help|?'      => \$opt_help,
            'man'         => \$opt_man,
            'statflags=s' => \$stat_flags,
            'tops=s'      => \@tops,
            'verbose+'    => \$verbose,
	   )
    or pod2usage(2);

pod2usage (1) if $opt_help;
pod2usage (-verbose => 2) if $opt_man;
( $prog = $0 ) =~  s{.*/}{}o;

## If no arguments were given, then allow STDIN to be used only
## if it's not connected to a terminal (otherwise print usage)
pod2usage ("$prog: No files given.")  if ((@ARGV == 0) && (-t STDIN));

# setbuf on STDERR.
$ofh = select (STDERR); $| = 1; select ($ofh);

@diffout = ();
$kill_errs = ($verbose) ? "" : "2>/dev/null";

#
# if tops is not set, infer the older directory.  Long Term - find out if cvs file.
#
if (not scalar @tops) {
    my @os = ( "\.edit" );

    while ($od = shift @os) {
	last if (infer_orig $od);
    }
}

if (not scalar @tops) {
    pod2usage ("$prog: could not infer, need to define tops.");
}

if (not -d $tops[0]) {
    if (-d "../$tops[0]") {
	chdir '..';
	print STDERR qx{pwd} if $verbose;
    }
    else {
	die "could not find $tops[0]\n";
    }
}

while ($path = shift @ARGV) {
    my $recurse = (-d "$tops[0]/$path") ? 'r' : '';
    $cmd = "diff $diff_flags${recurse} $tops[0]/$path $tops[1]/$path $kill_errs";
    print "tops={@tops}\n$cmd\n" if $opt_debug;
    open DIFFIN, "$cmd |" or die "open {$cmd}\n";
    while (<DIFFIN>) {
	next if (m{^Common});
	push @diffout, $_;
    }
}

open DSI, "|diffstat $stat_flags" or die "open stat pipe\n";
print DSI @diffout;
print while (<DSI>);
close DSI;
print "\n", @diffout;

__END__

=head1 NAME

B<ds> - diffstat + diff from one command

=head1 SYNOPSIS

B<ds> [options] ...

=head1 OPTIONS

=over 4

=item B<--debug>

run without action, printing debug messages.

=item B<--diffflags>

flags to pass to diff.  default -Nwupa.

=item B<--help>

print the synopsis only.  see B<--man>.

=item B<--man>

print the complete manpage.

=item B<--statflags>

flags to pass to diffstat.  default is {$stat_flags}.

=item B<--tops>

Top level directories to diff with the appended paths.  If not specified,
infer from current directory if possible.

=item B<--verbose>

whistle while we work.  multiple calls increase the verbosity level.

=back

=head1 DESCRIPTION

Runs diff over the list of files, collecting the output.  When complete, outputs
the stats followed by the diffs to stdout.

=head1 EXAMPLES

examples

=head1 NOTE

note

=head1 BUGS

Undoubtedly.  Contact the author with the particulars if this is stopping your progress.

=head1 FILES

B<ds> - perl script

=head1 AUTHOR

Doug Maxey <dwm@austin.ibm.com>

=cut