All git branches last commit author.

git_branch_author

#!/usr/bin/env perl
use strict;
use warnings;
use utf8;

{
    my @lines = `git branch -rv`;
    foreach my $line ( @lines ) { 
        chomp $line;
 
        my ( $branch, $commit, @messages ) = split ' ', $line;
        my $msg = join ' ', @messages;
        next unless $commit =~ qr/^[0-9a-zA-Z]+$/;

        my @show_lines = `git show --format=format:%an $commit`;
        chomp( my $author = $show_lines[0] );

        print "branch: $branch, author: $author, msg: $msg, commit: $commit\n";
    }   
}