Utils

This is a small set of tools that scratch various personal itches. You may or may not find any of them remotely useful.

(See also the excellent moreutils.)

alert

A thin wrapper around blink1-tool, the command-line interface to the nifty little USB LED gadget known as blink(1).

It triggers ten flashes over five seconds, in the color of your choice. If no color is given, it defaults to white. Specify a time in the future and it will wait until then to flash.

bur

Short for "brew update report". It takes the output of brew update and generates an HTML document consisting of a four-column table: the three left column contain the name of the formula, possibly accompanied by adornments, and linked to the corresponding project's home page; each cell in the right column contains the corresponding description. The aforementioned adornments include green check marks denoting installed formulae, and the previous name and an arrow in the case of renamed formulae.

dl

find, mdfind, grep -l, and similar commands emit a succession of file paths, one per line. These are very easy for programs to parse. Unfortunately, they're a little harder for humans to read, especially when the question the humans are trying to answer is "Which directory should I go poking around in first?"

dl takes a succession of paths as input, performs some grouping, and emits a set of per-directory listings.

As a simple example, grep -rl ruby in one of my personal directories generates the following output:

./artifacts/closest_polynomial
./artifacts/envy
./artifacts/fizzbuzz.rb
./artifacts/rcd
./artifacts/uri_descape
./util/dl
./util/jj
./util/loo
./util/path
./wip/frag
./wip/modulist
./wip/nn

Piped through dl, this produces:

./artifacts
  closest_polynomial
  envy
  fizzbuzz.rb
  rcd
  uri_descape

./util
  dl
  jj
  loo
  path

./wip
  frag
  modulist
  nn

The optional -d argument goes one step further and omits mention of the files, listing only the directories.

git-cull

GitHub's pull-request model means that the local copy of any work repository I frequently pull from tends to accumulate lots of old branches, since the GitHub deletion of those branches immediately following the merge has no effect upon the corresponding local branches. git cull steps in to fix this. It notes the starting branch, switches over to master, gets a list of merged branches, and proceeds to delete them. Finally, if the starting branch wasn't one of the ones culled, it switches back to it.

git-purge

If you were to take a cue from Ripley in Aliens, and set out to build a flamethrower that sported both a chainsaw bayonet and a grenade launcher capable of flinging water balloons filled with hydrochloric acid, then you might ultimately produce a tool as dangerous, as prone to creating inadvertent collateral damage, as this one.

There are nevertheless times when you want to brutally and thoroughly clear a repository, or part thereof, of any local changes, without going to the trouble of cloning a fresh copy from origin. That's where this script comes in.

Given a target path, it will:

git reset -q HEAD ${target}
git checkout -- ${target}
git clean -fd ${target} 

If not given a target path, it will default to the current directory. Just to be crystal clear: this is a tool designed from the outset to throw away data, so use with care.

git-report

A very, very simple wrapper that just does the following:

git fetch
git status --column
git stash list

It's a one-command mechanism for getting a quick report on the state of the current repository and branch.

jj

This tool pretty-prints JSON. In this, it is much like the doubtless orders-of-magnitude faster binary jsonpp. Unlike jsonpp, however, it does not expect/demand to be given input in the form of one object per unbroken line. (To put it another way: jsonpp chokes when fed properly- or even partially-formatted JSON, such as its own output, while jj does not.)

There are some minor differences in output style between jj and jsonpp. The former, for instance, always splits an array over multiple lines, even when the array in question is empty, whereas the latter prints empty arrays on a single line.

loo

Short for last occurrence only. (Get your mind out of the gutter.) loo removes all but the last instance of any repeatedly- occurring lines from its input. Unlike uniq, it's not limited to repitions of successive lines.

Given the input:

Alice
Bob
Alice
David
Charles
David

loo would emit:

Bob
Alice
Charles
David

Since it would drop the first occurrences of 'Alice' and 'David'. If invoked as foo (via the magic of soft/hard links), it will instead produce output containing only the first instance of repeatedly- occurring lines. The above input would become:

Alice
Bob
David
Charles

modulist

Short for "module list". Stash lists of the locally-installed Homebrew packages and Ruby gems to ~/.config/packages. Each created file has a datestamp: previous stashed lists for the same host, if present, are deleted after the new one has been written.

path

At least 50 cents of solution to a nickel's worth of problem. So it goes. I hate deciphering the output of echo $PATH; now I don't have to. By default, this script pretty-prints the value of $PATH, with one entry per line. However, it can also be used to generate a new colon-separated value for $PATH, optionally removing duplicate occurrences of paths.

spine

Take output split into two columns by a known substring, the 'spine', and align it so that it's centered on said spine.

foo: bar
very long string: baz

Would become:

             foo: bar
very long string: baz