Bash: Your forgotten friend (part 2)

17 Jun 2011

Aliases are one of the core portions of Bash that will help you become more productive almost immediately. To define an alias, the command is simply:

alias short='long command goes here'

Super simple! To save aliases, however, you'll need to put them in your .bash_profile so they load automatically. To see a list of currently defined aliases, type alias. Here are my aliases, chunk by chunk, and a brief bit about what they do.

# ALAISES
# set some aliases
case $OSTYPE in
    linux*)
        # Linux Specific
    ;;
    darwin*)
        # Mac Specific
        alias mvim='/Applications/MacVim.app/Contents/MacOS/Vim -g'
        alias agi='sudo port install'
    ;;
    *)
  ;;
esac

This bit of code sets up os specific commands. It is especially helpful when porting your config file between various locations as I do. Although I haven't setup any linux specific commands, prime candidates for this would be a different `LS_COLORS` environment variable (linux handles it differently than macs) or commands for installing software (such as apt-get or other variants).

# Global
alias l='ls -lah'       # Long view, show hidden
alias ls='ls -GFp'      # Compact view, show colors
alias la='ls -AF'       # Compact view, show hidden
alias ll='ls -lFh'      # Long view, no hidden
alias grep='grep --color=auto' # Always highlight grep search term
alias ping='ping -c 5'  # Pings with 5 packets, not unlimited
alias df='df -h'        # Disk free, in gigabytes, not bytes
alias du='du -h -c'     # Calculate total disk usage for a folder
alias ..='cd ..'        # Go up one directory
alias ...='cd ../..'    # Go up two directories
alias servethis="python -c 'import SimpleHTTPServer; SimpleHTTPServer.test()'"
alias clr='clear;echo "Currently logged in on $(tty), as $(whoami) in directory $(pwd)."'</pre>

These aliases, and those subsequently defined, are global to all installations. The first four aliases are permutations of the `ls` command. They allow quick access to various filesystem views, without trying to remember the flags (the extra stuff after the command) that displays them.

The last two elements bear specific explanation. The clr command clears the current buffer (screen) and tells you which user you're on and which directory you're looking at. This doesn't serve a lot of purpose as that information is part of my prompt, but does help alleviate blank page syndrome. The other command, servethis, spawns a small webserver on your computer which allows you to quickly serve files to co-workers.

# Git Aliases
alias gb='git branch'
alias gba='git branch -a'
alias gc='git commit -v'
alias gl='git pull'
alias gp='git push'
alias gst='git status'
alias gd='git diff | $GIT_EDITOR -'

# HG ALIASES
alias hgst='hg status'
alias hgd='hg diff | $GIT_EDITOR -'</pre>

These are mostly helper aliases that serve to only shorten longer commands. The one interesting bit here is the use of the environment variable $GIT_EDITOR, which I have defined in my script. Environment variables are defined by using the syntax:

export GIT_EDITOR='mvim -f'

This can then be referenced as $GIT_EDITOR in any and all shell scripts.

In the last installment of this series, I'll go over the bash functions I use and how they make life easier.