In case you find yourself in need of a way to turn an svn revision into a git patch that can be applied with ‘git am’, keeping the commit message and authorship information, here’s a script I used recently:

#!/usr/bin/python
#
# svnrev2git.py - Convert an SVN revsion to a Git patch.
#
# Author: James Bowes <jbowes@repl.ca>
#
# Usage:
#   $> cd my-svn-repo
#   $> python svnrev2git.py [AUTHORS_FILE] [REV_RANGE | REVSION [REVISION..]]
#
#   AUTHORS_FILE - a CSV of  svn username, full name, email
#   REV_RANGE - an svn revision range, like 100-700
#   REVISION - a single svn revision
#
#   You may specify either a revision range, or a series of individual
#   svn revisions
#
# Output:
#   A series of git style patch files, one per svn revision, which can then be
#   applied with 'git am'
#
# Why use this instead of 'git svn'?
#   I had done a large repo conversion via git svn where we wanted no downtime
#   for the switchover. After removing the git svn specific info from our git
#   commits, I used this tool to bring in commits from svn, keeping svn and git
#   in sync, until we were ready to switch.

import sys
import commands

def svnlog_to_gitlog(authors, svnlog):

    lines = svnlog.split("\n")
    lines = lines[1:-1]

    metainfo = lines[0].split(" | ")
    subject = lines[2]
    description = lines[3:]

    author = metainfo[1]

    day = metainfo[2].split("(")[1][:-1]
    time = metainfo[2].split(" ")[1]
    offset = metainfo[2].split(" ")[2]

    gitlog = []
    gitlog += ["From: %s <%s>" % authors[author]]
    gitlog += ["Date: %s %s %s" % (day, time, offset)]
    gitlog += ["Subject: [PATCH] %s" % subject]
    gitlog += [""]
    gitlog += description
    gitlog += [""]

    return '\n'.join(gitlog)

def svndiff_to_gitdiff(svndiff):
    lines = svndiff.split("\n")

    gitdiff = []
    for line in lines:
        if line.startswith("--- "):
            gitdiff.append("--- a/" + line[4:])
        elif line.startswith("+++ "):
            gitdiff.append("+++ b/" + line[4:])
        else:
            gitdiff.append(line)

    return '\n'.join(gitdiff)

def make_patch(authors, rev):
    out = commands.getoutput("svn log -c %s ." % rev)

    if len(out.split("\n")) < 2:
        print "skipping r%s" % rev
        return

    patch = open(rev + ".patch", 'w')
    patch.write(svnlog_to_gitlog(authors, out))
    patch.write("---\n\n")

    out = commands.getoutput("svn diff -c %s ." % rev)
    patch.write(svndiff_to_gitdiff(out))

    patch.write("\n---\n")
    patch.write("svnrev2git.py\n")

    patch.close()
    print "wrote %s.patch" % rev

def main(args):
    author_file = open(args[0])
    authors = {}

    print "loading authors"
    for line in author_file.readlines():
        parts = line.strip().split(", ")
        authors[parts[0]] = (parts[1], parts[2])

    author_file.close()

    revs = args[1:]

    if len(revs) == 1 and '-' in revs[0]:
        start, end = revs[0].split('-')
        start = int(start)
        end = int(end)
        revs = [str(x) for x in range(start, end + 1)]

    for rev in revs:
        make_patch(authors, rev)

if __name__ == "__main__":
    main(sys.argv[1:])

Making your own velcro cable ties is a great idea. $2 in materials made as many cable ties as Wal-Mart was selling for $13. Thrifty!

I’d suggest sewing the velcro together vs stapling, especially if you have cats that are far too curious about staples.

Growing up on the east coast of Canada, this is how I imagined Toronto to be, like, 24/7.

I’ve been here for nine months or so, and have yet to be invited to any trendy VICE parties. Just so you know, VICE, I am very willing to grow out some stubble and wear vintage clothing or an ironic t-shirt for the event.

Toronto is great though, even without the free Red Stripe.

Here’s a quick little script I wrote up (adapted from this perlmonks post) to show git repository activity as an ascii graph, like so:

The X axis represents a day, with the current day being on the far right. The Y axis is no. of lines added + no. of lines deleted during that day.

EDIT (2009/02/03):

WordPress.com won’t let me attach a .pl file, so here’s the contents:

#!/usr/bin/perl
#
# git-graph.pl - Generate an ascii graph of git repository activity
#
# Copyright (C) 2008 James Bowes <jbowes@dangerouslyinc.com>
#
# Graphing routine Adapted from http://www.perlmonks.org/?node_id=336907

sub get_activity {
    my $day = shift;
    my $git_cmd = 'git diff --shortstat "@{' . ($day + 1) .' day ago}" "@{' .
                  ($day or "0") . ' day ago}"';
    $res = `$git_cmd 2> /dev/null`;

    $res =~ /, (.*?) insertions\(\+\), (.*?) deletions\(-\)/;
    $activity = $1 + $2;

    return $activity;
}

@deltas = ();
foreach $day (0..70) {
    push (@deltas, get_activity ($day));
}

print ("\n");
print graph(@deltas);
print ("\n");

sub graph {
  my( $i, $magic, $m, $p, $top, @g ) = ( 0, 20, 7, 70, 0, () );

  foreach $pad (0..($p - scalar(@_))) {
      push (@_, 0);
  }

  @_ = reverse @_; 

  for (0..($p)) {
      $top = ($top > $_[$_]) ? $top : $_[$_];
  }

  $top = $top - ($top % 100) + 100;

  my $s = $top > $magic ? ( $top / $magic ) : 1;  ### calculate scale

  for (0..$magic) {
    $g[$_] = sprintf("%" . ($m - 1) . "d |", $_ * $s) .
             ($_ % 5 == 0 ? '_' : ' ') x ($p);
    for $i (0..($p)) {
        substr($g[$_], ($i + $m), 1) = '#' if ($_[$i] / $s) > $_;
    }
  }
  join( "\n", reverse( @g ), ' Date:  ' . '^^^^^^|' x ( $p / 7 ));
}  # end sub graph

__END__

I found it hard to find good instructions for installing ruby gems as a non-root user without installing the gem package locally as well. Here’s what I figured out; hopefully this will save someone else some time in the future:

Make a directory for gem installation:

$> mkdir ~/.gems

Set up your .gemrc for gem install-time configuration:

$> cat << EOF > ~/.gemrc
gemhome: $HOME/gems
gempath:
- $HOME/gems
- /usr/lib/ruby/gems/1.8
EOF

Set up some environment variables for run-time:

$> cat << EOF >> ~/.bashrc
export GEM_HOME=$HOME/gems
export GEM_PATH=$HOME/gems:/usr/lib/ruby/gems/1.8/
export PATH=$PATH:$HOME/gems/bin
EOF

Source your bashrc and you’re all set.

UPDATE (Apr 18, 2009): gem seems to do this on its own now, so just adding

export PATH=$PATH:$HOME/.gem/ruby/1.8/bin

to your .bash_profile should be enough.

[jbowes@laptop ~]$ history | awk '{a[$2]++ } END{for(i in a){print a[i] " " i}}'|sort -rn|head
211 git
148 fg
107 ls
99 cd
89 python
43 make
26 vim
23 sudo
20 nosetests
19 player/swfplay

[jbowes@workstation ~]$  history | awk '{a[$2]++ } END{for(i in a){print a[i] " " i}}'|sort -rn|head -n 12
163 ls
156 cd
115 svn
76 vim
70 screen
55 fg
47 exit
35 sudo
30 git
21 yasql

Seen on Adrian’s and Mike’s blogs.

Please stop Bell from doing crazy stuff.  Thanks!

Love,

James

Our boy cat Julius passed away a few weeks ago. It was pretty shocking, as he was quite young and his passing was sudden and unexpected. While we miss him terribly, Cherie and I didn’t want Spook to get too used to being an only cat again.

So this weekend we picked up a new little fellow from the Toronto Humane Society:

He doesn’t have a name yet, but he sure has quite a pair of ears on him!

Agile Tsar Dmitri Dolguikh pointed out Project Euler yesterday, which is a website containing a series of short programming problems. It reads a bit like bonus questions on a math exam, which is actually quite refreshing compared to the day-to-day problems at work. For added fun, I’m trying to run through the problems in Common Lisp.

So far I have completed 4 out of 179 problems, which makes me 2% genius, according to the site.

A lot of people are linking to this article about the state of the practice in CS curriculum and its use of Java creating dull replaceable drones.

mdehaan points out a wonderful section wherein the authors relate Java programming to a plumber in a hardware store, finding pieces and putting them together to solve a problem, rather than their unmentioned alternative (maybe an artist molding clay?)

If this is true, then we, the software industry and software engineering fields, are done. We have found the holy grail: true modularity and reusable software components. Drop whatever language you’re using and switch to Java.