How to find out where alias (in the bash sense) is defined when running Terminal in Mac OS X

Question

How can I find out where an alias is defined on my system? I am referring to the kind of alias that is used within a Terminal session launched from Mac OS X (10.6.3).

Answer 1

A bit late to the party, but I was having the same problem (trying to find where the "l." command was aliased in RHEL6), and ended up in a place not mentioned in the previous answers. It may not be found in all bash implementations, but if the /etc/profile.d/ directory exists, try grepping there for unexplained aliases. That's where I found:

[user@server ~]$ grep l\\. /etc/profile.d/*
/etc/profile.d/colorls.csh:alias l. 'ls -d .*'
/etc/profile.d/colorls.csh:alias l. 'ls -d .* --color=auto'
/etc/profile.d/colorls.sh:  alias l.='ls -d .*' 2>/dev/null
/etc/profile.d/colorls.sh:alias l.='ls -d .* --color=auto' 2>/dev/null

The directory isn't mentioned in the bash manpage, and isn't properly part of where bash searches for profile/startup info, but in the case of RHEL you can see the calling code within /etc/profile:

for i in /etc/profile.d/*.sh ; do
  if [ -r "$i" ]; then
    if [ "${-#*i}" != "$-" ]; then
      . "$i"
    else
      . "$i" >/dev/null 2>&1
    fi
  fi
done