Is there an easy way to avoid duplicating commands in bash's HISTIGNORE?

Question

I'd like to ignore all invocations of a command in my bash history, regardless of arguments. For example, to exclude all of ls, ls -l, and ls SOME_DIRECTORY, my understanding is that I'd need to do:

HISTIGNORE='ls:ls *'

I can't use just HISTIGNORE='ls*' because that also would ignore other commands that happen to start with ls, which is undesirable. However, needing to specify ls and ls * is annoying and error-prone as I add entries to HISTIGNORE.

Is there a pattern that I can use to match a command by itself and with arguments?

Answer 1

HISTIGNORE pattern matching honors the setting of the extglob shell option and, with extended globbing, you can use this to match commands that start with ls and are followed by either a space and then anything else, or by nothing (end of the line).

shopt -s extglob
HISTIGNORE='ls@( *|)'

The @(foo|bar) format of bash extended globs will match exactly one of foo or bar. Here, the pattern we are giving is ls@( *|) so it will match ls at the beginning of the line and then either a space and 0 or more other following characters, or no characters at all.

Here it is in action:

$ shopt -s extglob 
$ export HISTIGNORE='ls@( *|)'
$ history -c
$ ls > /dev/null 
$ ls * > /dev/null
$ ls -la > /dev/null
$ ls file > /dev/null
$ lsa
-bash: lsa: command not found
$ history 
    1  lsa
    2  history