Hide make targets from shell when users autocomplete in bash

Question

Is there a way to flag some targets in a Makefile so that they don't appear at all in the shell when the user types make and then presses Tab ? I am having a Makefile with too many recipes and I don't want them all to appear in the shell autocompletion when a users presses Tab looking for targets.

Answer 1

After studying the problem and coming up with a solution that I wrote in the first answer, I realized that there is another very simple way.

Just start the target's names you don't want to show beginning with a dot.

Example:

.PHONY: foo .hiddentarget
foo: foo.x .hiddentarget
foo.x: foo.c
        touch foo.x
.hiddentarget: foo.x
        echo foo.x ok, I believe

And that's all you need!

I came to this idea after trying to figure out how to prevent a target named .HIDDENGOALS being called by mistake and run all hidden goals. :)

Warning Although I don't see any, I'm not sure if there isn't any side effect on using target names like this ".targetname" (starting with a dot).

Answer 2

To hide some targets, you'd need to hack the autocompletion function of your shell. bash uses /etc/bash_completion and /etc/bash_completion.d/*for that.

Can't recall how tcsh does it.

Answer 3

I've observed that this also works by starting the target with an underscore

_hiddentarget:
    @echo "Running hidden target" 

Answer 4

EDITED Best to read the other answer (target name starting with a dot). But I'll let this answer here, as the programming part may help other similar issues.

Ok, it took me some time to come up with a solution. This is a (good) draft, and hopefully it will do the job right.

You must edit the file /usr/share/bash-completion/completions/make (for Debian Wheezy, or some similar to your system)

In my current version, line numbers 70 to 73 have the code:

70         COMPREPLY=( $( compgen -W "$( make -qp $makef $makef_dir 2>/dev/null | \
71             awk -F':' '/^[a-zA-Z0-9][^$#\/\t=]*:([^=]|$)/ \
72             {split($1,A,/ /);for(i in A)print A[i]}' )" \
73             -- "$cur" ) )

Replace then for the foloowing code:

 70         HIDDENGOALS="$(make -qp | grep '^\.HIDDENGOALS:' | cut -d' ' -f2- | sed 's/ /\\|/g')"
 71         if [[ "$HIDDENGOALS" == "" || "$HIDDENGOALS" == ".HIDDENGOALS:" ]]; then
 72             COMPREPLY=( $( compgen -W "$( make -qp $makef $makef_dir 2>/dev/null | \
 73                 awk -F':' '/^[a-zA-Z0-9][^$#\/\t=]*:([^=]|$)/ \
 74                 {split($1,A,/ /);for(i in A)print A[i]}' )" \
 75                 -- "$cur" ) )
 76         else
 77             COMPREPLY=( $( compgen -W "$( make -qp $makef $makef_dir 2>/dev/null | \
 78                 awk -F':' '/^[a-zA-Z0-9][^$#\/\t=]*:([^=]|$)/ \
 79                 {split($1,A,/ /);for(i in A)print A[i]}' \
 80                 | grep -ve "$HIDDENGOALS" )" \
 81                 -- "$cur" ) )

Now inside your makefile you can use the following special target to hide goals from bash autocompletion:

 .HIDDENGOALS: somegoal anothergoal goalstohide

much like a .PHONY special target (there are some differences).

Careful:

(I) As this solution works through a grep -ev, the special target isn't quite so. It will use anything in the line to match just the way a Regular Expression does.

So, if you have a target, say, copy2, and another copy, writting

 .HIDDENGOALS: copy

will hide both goals!

I let the solution to this behavior as an exercise to the reader! ;)

(II) Another thing to notice, the : is hardcoded to be next to .HIDDENGOALS:, meaning that although targets allow spaces like .PHONY :, this special hack doesn't.

(III) I think it would be better to edit a local file instead of /usr/share/bash-completion/completions/make, to avoid losing the information when an upgrade comes. But I did not tested any options. If you know, please comment and I'll update this answer.

(IV) There is a slight chance of a curious run the very target .HIDDENGOALS with a make .HIDDENGOALS. That would run all hidden goals. And autocompleting the name wasn't possible, which lead me to the other quite simple answer!