git-shortlog script

Attached is the 'git-shortlog' script I whipped up, to mimic the 
shortlog script that was used back in the BitKeeper days.

shortlog reads a changelog in the 'git-whatchanged' format, such as

	git-whatchanged | git-shortlog
		or
	git-shortlog changes.txt

and outputs the changes sorted by author:

	author1:
	  cset 1-line desc
	  cset 1-line desc
	  ...
	author2:
	  cset 1-line desc
	  ...
	...

Since git distinguishes 'author' from 'committer', I ran

	git-whatchanged | git-shortlog > changes.txt

to look at the kernel authors throughout the entire history [of which is 
in git].

It's fun to browse, since this is the first time we've been able to get 
a better picture who is actually writing the patches, versus committing 
them.  See changes.txt.bz2, attached.

	Jeff




#!/usr/bin/perl -w

use strict;

my ($author, $desc, %map);
my $pstate = 1;

while (<>) {
	# get author
	if ($pstate == 1) {
		next unless /^Author: (.*)$/;
		$author = $1;
		$pstate++;
	}

	# skip to blank line
	elsif ($pstate == 2) {
		next unless /^\s*$/;
		$pstate++;
	}

	# skip to non-blank line
	elsif ($pstate == 3) {
		next if /^\s*$/;
		chomp;
		$desc = $_;

		&shortlog_entry($author, $desc);

		$pstate = 1;
	}

	else {
		die "invalid parse state $pstate";
	}
}

&shortlog_output;
exit(0);


sub shortlog_entry($$) {
	my ($tmp_author, $tmp_desc) = @_;

	$tmp_desc =~ s#/pub/scm/linux/kernel/git/#/.../#g;
	$tmp_desc =~ s#\[PATCH\] ##g;
	$tmp_desc =~ s#^\s+##g;

	if (exists $map{$tmp_author}) {
		# grab ref
		my $obj = $map{$tmp_author};

		# add desc to array
		push(@$obj, $tmp_desc);
	} else {
		# create new array, containing 1 item
		my @arr = ($tmp_desc);

		# store ref to array
		$map{$tmp_author} = \@arr;
	}
}

sub shortlog_output {
	my ($obj);

	foreach $author (sort keys %map) {
		print "$author:\n";

		$obj = $map{$author};
		foreach $desc (@$obj) {
			print "  $desc\n";
		}

		print "\n";
	}
}