Merge results from two "find" commands

Question

I'd like to find all directories that contain both a Makefile and a file matching *.tex. The command find or locate easily finds one or the other. But how can those results be merged or intersected, to yield just the directories desired?

A useful answer generalizes to other filenames. Even better, it can merge more than two such queries.

(I don't see how to apply find's boolean operators, e.g. "and" expr1 -a expr2. Ditto for locate -A. Maybe two searches, strip the filenames and keep the paths, sort -u, into comm -12 <(cmd1) <(cmd2)?)

xenoid · Accepted Answer · 2017-05-29T16:13:34.410

4

Just use -a to 'AND' conditions:

find . -type d -exec test -f {}/Makefile \; -a -exec bash -c 'compgen -G '{}'/*.tex >/dev/null;exit $?' \; -print

In slow-mo:

-exec test -f {}/Makefile \; checks if Makefile exists in the directory
-exec bash -c 'compgen -G '{}'/*.tex >/dev/null;exit $?' checks if there are any *.tex files in the directory
the whole line tests true only if both test are true
in that case print the directory name

Ran on:

./no1
./no1/yes3
./no1/yes3/foo.tex
./no1/yes3/Makefile
./no1/no3
./no1/no
./no1/Makefile
./q
./no2
./no2/foo.tex
./yes1
./yes1/foo.tex
./yes1/Makefile
./yes2
./yes2/foo.tex
./yes2/Makefile

Gives:

./no1/yes3
./yes1
./yes2

edited May 29 '17 at 16:13

answered May 29 '17 at 15:40

xenoid

10,012

1

+1. I never knew you could use -exec as a test; man find lists tests and actions separately and -exec is under "actions" there. Your answer is a learning material to me. – Kamil Maciorowski May 29 '17 at 18:24
Also for me... never used compgen before. – xenoid May 29 '17 at 20:13
This answer is not perfect by itself (e.g. it doesn't mention that -a connects tests by default, you may omit it) but what I learnt from it turned out to be so powerful (custom tests like this, yay!) I decided to award it. Keep up the good work. – Kamil Maciorowski Sep 23 '17 at 07:52
And when I started using Unix I thought find was an over complicated command :) – xenoid Sep 23 '17 at 08:02
When I learnt from this answer, I was not aware of this: never embed {} in the shell code. – Kamil Maciorowski Dec 01 '21 at 15:43

l0b0 · Answer 2 · 2017-05-29T14:52:08.007

1

find can't do "sub-queries" to print directories which contain some files, so comm is indeed the way to go:

comm -12 <(find . -name Makefile -exec dirname {} \; | sort ) <(find . -name '*.tex' -exec dirname {} \; | sort)

You could also loop over directories (recursively with globstar) which might be faster (compgen source):

for directory in */
do
    if [ -e "${directory}/Makefile" ] && compgen -G "${directory}/"*.tex > /dev/null
    then
        printf '%s\n' "${directory}"
    fi
done

edited May 29 '17 at 14:52

answered May 29 '17 at 14:45

l0b0

7,351

This answer is easier to understand and to remember, but xenoid's is single-pass so it's faster on a big filesystem. (locate would be far faster!) – Camille Goudeseune May 30 '17 at 15:44

Merge results from two "find" commands

2 Answers2