[SOLVED] Output bash alias full form before running

Issue

I like using bash aliases quite often (I am using .zshrc) but I would prefer that the aliases would show what they do. This is because I have to pair program quite often. I know doing type alias_name and also alias alias_name displays a description. Is there a way to get my aliases to display their full form before they run? I tried prepending my aliases like alias alias_name='type alias_name && ...'. However the output for this would also include the prepended code as expected. Is there a way around it?

Solution

In bash and zsh you can define a command that prints and executes its arguments. Then use that command in each of your aliases.

printandexecute() {
  { printf Executing; printf ' %q' "$@"; echo; } >&2
  "$@"
}
# instead of `alias name="somecommand arg1 arg2"` use 
alias myalias="printandexecute somecommand arg1 arg2"

You can even automatically insert the printandexecute into each alias definition by overriding the alias builtin itself:

printandexecute() {
  { printf Executing; printf ' %q' "$@"; echo; } >&2
  "$@"
}
alias() {
  for arg; do
    [[ "$arg" == *=* ]] &&
    arg="${arg%%=*}=printandexecute ${arg#*=}"
    builtin alias "$arg"
  done
}

# This definition automatically inserts printandexecute
alias myalias="somecommand arg1 arg2"

Example in an an interactive session. $ is the prompt.

$ myalias "string with spaces"
Executing somecommand arg1 arg2 string\ with\ spaces
actual output of somecommand

Answered By - Socowi