3.5.1. What are aliases?

An alias allows a string to be substituted for a word when it is used as the first word of a simple command. The shell maintains a list of aliases that may be set and unset with the alias and unalias built-in commands. Issue the alias without options to display a list of aliases known to the current shell.

franky: ~> alias
alias ..='cd ..'
alias ...='cd ../..'
alias ....='cd ../../..'
alias PAGER='less -r'
alias Txterm='export TERM=xterm'
alias XARGS='xargs -r'
alias cdrecord='cdrecord -dev 0,0,0 -speed=8'
alias e='vi'
alias egrep='grep -E'
alias ewformat='fdformat -n /dev/fd0u1743; ewfsck'
alias fgrep='grep -F'
alias ftp='ncftp -d15'
alias h='history 10'
alias fformat='fdformat /dev/fd0H1440'
alias j='jobs -l'
alias ksane='setterm -reset'
alias ls='ls -F --color=auto'
alias m='less'
alias md='mkdir'
alias od='od -Ax -ta -txC'
alias p='pstree -p'
alias ping='ping -vc1'
alias sb='ssh blubber'
alias sl='ls'
alias ss='ssh octarine'
alias sss='ssh -C server1.us.xalasys.com'
alias sssu='ssh -C -l root server1.us.xalasys.com'
alias tar='gtar'
alias tmp='cd /tmp'
alias unaliasall='unalias -a'
alias vi='eval `resize`;vi'
alias vt100='export TERM=vt100'
alias which='type'
alias xt='xterm -bg black -fg white &'

franky ~>

Aliases are useful for specifying the default version of a command that exists in several versions on your system, or to specify default options to a command. Another use for aliases is for correcting incorrect spelling.

The first word of each simple command, if unquoted, is checked to see if it has an alias. If so, that word is replaced by the text of the alias. The alias name and the replacement text may contain any valid shell input, including shell metacharacters, with the exception that the alias name may not contain "=". The first word of the replacement text is tested for aliases, but a word that is identical to an alias being expanded is not expanded a second time. This means that one may alias ls to ls -F, for instance, and Bash will not try to recursively expand the replacement text. If the last character of the alias value is a space or tab character, then the next command word following the alias is also checked for alias expansion.

Aliases are not expanded when the shell is not interactive, unless the expand_aliases option is set using the shopt shell built-in.

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