Mind Blowing Command Line Time Savers

Whether you’re an old skool unix hacker or a Mac user who uses Terminal regularly, there’s lots of ways to save time on the command line.  I’ve mentioned a few of the following tips on twitter.com/quiteuseful, but I thought it’d be handy to collect them all here.

Bash

!! - repeats the last command

history n - shows the last n things you’ve typed

My favourite shortcut is ctrl-r: this lets you search through history interactively.  I probably use ctrl-r every day, I really don’t like repeating myself!

xargs is a useful command: it’ll construct argument lists.  It works really well with pipes:

find *.rb | xargs grep -i "ActiveRecord"

Aliases

My aliases end up getting ridiculously short.  I don’t ssh into my screen session with IRC, etc, I just type “irc”.  I don’t even type ls either:

alias l='ls -Gla'

If you’re on a Mac you should have a ~/.profile file, so you can add aliases there.

Apps: ack and cdargs

My two favourite command line time savers are ack and cdargs.  I found myself searching code a lot, and ack works better than grep for this.  It’s also useful for finding documentation: why view the Rails HTML docs when you can ack the Rails source?  Give it a go with one of your regularly used libraries!

You can get ack from betterthangrep.com.

cdargs lets you bookmark directories, then cd to them with a shorter name.  I have a lot of code in ~/Documents/Code/project_name, and I move between projects every day.  I bookmarked these with ca, then I cd to them with cv project-short-name.

You can get cdargs here: cdargs.

These apps don’t sound like a big deal, but they really help me switch between projects.  Ack is great for navigating code too: you can get plugins for TextMate or Vim.