Bash – List only temporary aliases in bash

There is a great thread about this on the Ubuntu forums. Ole J proposes the following alias completion definition function:

function make-completion-wrapper () {
  local function_name="$2"
  local arg_count=$(($#-3))
  local comp_function_name="$1"
  shift 2
  local function="
    function $function_name {
      ((COMP_CWORD+=$arg_count))
      COMP_WORDS=( "$@" \${COMP_WORDS[@]:1} )
      "$comp_function_name"
      return 0
    }"
  eval "$function"
  echo $function_name
  echo "$function"
}

Use it to define a completion function for your alias, then specify that function as a completer for the alias:

make-completion-wrapper _apt_get _apt_get_install apt-get install
complete -F _apt_get_install apt-inst

I prefer to use aliases for adding always-used arguments to existing programs. For instance, with grep, I always want to skip devices and binary files, so I make an alias for grep. For adding new commands such as grepbin, I use a shell script in my ~/bin folder. If that folder is in your path, it will get autocompleted.

To list active aliases, run:

alias

To see names of all active functions, run:

declare -F

To see the names and definitions of all active functions, run:

declare -f

More

The information on aliases is also available is a script-friendly format with:

declare -p BASH_ALIASES

man bash provides more info on the alias builtin:

   alias [-p] [name[=value] ...]
          Alias with  no  arguments  or  with  the  -p
          option  prints  the  list  of aliases in the
          form alias name=value  on  standard  output.
          When  arguments  are  supplied,  an alias is
          defined for each name whose value is  given.
          A  trailing  space in  value causes the next
          word to be checked  for  alias  substitution
          when  the  alias is expanded.  For each name
          in the argument list for which no  value  is
          supplied, the name and value of the alias is
          printed.  Alias returns true unless  a  name
          is   given  for  which  no  alias  has  been
          defined.

Regarding functions, man bash explains that declare can provide still more information is available if the extdebug option is set:

   Function  names  and definitions may be listed with
   the -f option to the  declare  or  typeset  builtin
   commands.  The -F option to declare or typeset will
   list the function names only  (and  optionally  the
   source  file and line number, if the extdebug shell
   option is enabled).

Links

1. http://ss64.com/bash/alias.html
2. http://linfo.org/alias.html