From 011e36350a1f8f20addaac753f2a4d3b359ab2d6 Mon Sep 17 00:00:00 2001
From: Dobrica Pavlinusic <dpavlin@rot13.org>
Date: Thu, 4 Aug 2022 09:03:59 +0200
Subject: [PATCH] merge git log from multiple repositories by date

---
 git-log-merge.pl | 66 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100755 git-log-merge.pl

diff --git a/git-log-merge.pl b/git-log-merge.pl
new file mode 100755
index 0000000..9886fdc
--- /dev/null
+++ b/git-log-merge.pl
@@ -0,0 +1,66 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+use autodie;
+use Data::Dump qw(dump);
+
+my @repos = qw(
+/home/dpavlin/dell-switch/running-config/
+/home/dpavlin/mikrotik-switch/backup/
+/home/dpavlin/tilera/backup/
+);
+
+my $debug = $ENV{DEBUG} || 0;
+$| = 1 if $debug;
+
+open(my $less, '|-', "less -R -S");
+
+my $commit;
+my $commit_next;
+
+our $fh;
+my $date_commit;
+
+sub get_commit {
+	my $repo = shift;
+	my $r = $fh->{$repo};
+	die "ERROR on $repo in ",dump($fh) unless $r;
+	while(<$r>) {
+		if ( m/(\e\[\d*m)?commit [0-9a-f]+/ ) {
+		#if ( m/commit [0-9a-f]+/ ) {
+			if ( ! defined $commit->{$repo} ) { # first time, read commit
+				$commit->{$repo} = $_;
+				warn "## first commit ",dump($_) if $debug;
+			} else {
+				$commit_next->{$repo} = $_;
+				warn "## --------------" if $debug;
+				last;
+			}
+		} elsif (m/Date:\s+([0-9-\+: ]+)/ ) {
+			$date_commit->{$1} = $repo;
+			warn "# $repo $1" if $debug;
+			$commit->{$repo} .= $_;
+		} else {
+			$commit->{$repo} .= $_;
+			warn "## $repo $. ",dump($_) if $debug;
+		}
+	}
+}
+
+foreach my $repo ( @repos ) {
+	$ENV{PAGER} = 'cat';
+	open(my $r, '-|', "git -C $repo log --date=iso --color @ARGV");
+	$fh->{$repo} = $r;
+	get_commit $repo;
+}
+
+
+while(1) {
+	#warn "# date_commit = ",dump($date_commit);
+	my $date = ( sort { $b cmp $a } keys %$date_commit )[0];
+	my $repo = $date_commit->{$date};
+	print "# $date $repo\n$commit->{$repo}";
+	$commit->{$repo} = $commit_next->{$repo};
+	delete $date_commit->{$date};
+	get_commit $repo;
+}
-- 
2.20.1