mjdominus

# This is the function that git-rebase--interactive uses to determine if the
# working tree is clean, and to bail out if not
require_clean_work_tree () {
        # test if working tree is dirty
        git rev-parse --verify HEAD > /dev/null &&
        git update-index --ignore-submodules --refresh &&
        git diff-files --quiet --ignore-submodules &&
        git diff-index --cached --quiet HEAD --ignore-submodules -- ||
        die "Working tree is dirty"
}

mjdominus

$ git branch 
  master
* snonk
$ git rev-parse master snonk
1333053e19b35008e74476b1549ecfed709c3d44
1333053e19b35008e74476b1549ecfed709c3d44
$ git name-rev --name-only HEAD
master
$ git rev-parse --symbolic-full-name --abbrev-ref HEAD
snonk

mjdominus

Say you want to separate commits to two sets of files, and you want to do this on the branch that starts at commit start and ends at commit end, so that if there are n of these commits, you'll end up with two new branches, each with n commits, one branch with just to the changes in the files in group X and the other with just the changes to the files in group Y.

First, we will create branch branch-X, for just the changes to files in group X:

git checkout -b branch-X start^
for commit in $(git rev-list --reverse start..endpoint); do
  git checkout $commit -- ((list of files and directories in X))
  git commit -C $commit
done

mjdominus

Why Lisp macros are cool, a Perl perspective

Original text from http://lists.warhead.org.uk/pipermail/iwe/2005-July/000130.html

Content

From: Mark Jason Dominus <[email protected]> 
Date: Jul 28, 2005 11:16 PM
Subject: Re: HOP -vs- SICP

To: [email protected]

mjdominus

Mathematics: What do grad students in math do all day?

by Yasha Berchenko-Kogan

A lot of math grad school is reading books and papers and trying to understand what's going on. The difficulty is that reading math is not like reading a mystery thriller, and it's not even like reading a history book or a New York Times article.

The main issue is that, by the time you get to the frontiers of math, the words to describe the concepts don't really exist yet. Communicating these ideas is a bit like trying to explain a vacuum cleaner to someone who has never seen one, except you're only allowed to use words that are four letters long or shorter.

What can you say?

mjdominus

#!/usr/bin/perl

my $M = shift() || 15;

# A node has [ N, [1, ... ] ]
# where N is the max of the [ 1, ... ]
sub children {
    my ($node) = @_;
    my ($N, $circ) = @$node;
    my @children;

mjdominus

    my %kv = map {$_ => [ $args{$_}, undef ]} @fields;

    my $nullcount = join " + ", map "(me.$_ IS NULL)", @fields;

    my $min_nulls = $self->base_rs->search(
        \%kv,
        { 'select' => [ { "min" => \$nullcount } ],
      });

    my $rs = $self->base_rs->search(\%kv);

mjdominus

my @f;
sub solve {
    my ($n, $x) = @_;
    return 1 if $x == 0 and $n == 0;
    return 0 if $x <= 0  || $n == 0;
    return $f[$n][$x] if defined $f[$n][$x];

    my $total = 0;
    for my $i (1 .. 12) {
        $total += solve($n-1, $x-$i);

mjdominus

04 00 * * *  /usr/local/bin/cronjob --rcpt [email protected] -c "yday=$(perl -le '@d = localtime(time - 7200); printf(q{\%04d-\%02d-\%02d}, $d[5]+1900, $d[4]+1, $d[3])'); $STARTERVIEW/bin/populate-email-open-tracking -v  /vol2/log/ziprecruiter-cron/track-logs/track_log.\$yday-?? && $STARTERVIEW/bin/job_search_email_opens_by_domain"


# Riddles: 
#  1. How many different quoting contexts are in this line?
#  2. How many different quote characters are there?
#  3. How deep is the deepest level of quote nesting?
#  4. Explain the difference between the first \ and the last \.
#  5. Which of the following changes would be innocuous:
#     a. "..." to '...'

mjdominus

!/usr/bin/perl

use BSD::Resource qw(setrlimit RLIMIT_VMEM RLIM_INFINITY);
my ($mem) = shift // usage();
@ARGV or usage();
my ($n, $s) = $mem =~ /\A (\d+) ([kmgKMG]?) \z/x or usage();
my $suf = { k => 1024,
            m => 1024 * 1024,
            g => 1024 * 1024 * 1024,
          };