Transforming a list of files separated by new lines into a variable

Question

Goal: I'm trying to find all instances of *.clj or *.cljs files recursively within a directory, store them in a string variable (separated by new lines) and then transform them.

So if the following clj(s) files are found within my directory dir1:

/dir1/dir2/hello1.clj
/dir1/dir2/hello2.clj
/dir1/dir2/hello3.cljs
/dir1/dir2/hello4.clj
/dir1/dir2/hello5.cljs

And my transformation is, let's say, merely to return the basename of each of these strings:

/dir1/dir2/hello1.clj -> hello1.clj
/dir1/dir2/hello2.clj -> hello2.clj
/dir1/dir2/hello3.clj -> hello3.clj
/dir1/dir2/hello4.clj -> hello4.clj
/dir1/dir2/hello5.clj -> hello5.clj

Then how can I write a function f such that

$ VAR=$(f dir1)

satisfies

$ echo "$VAR"
  hello1.clj
  hello2.clj
  hello3.clj
  hello4.clj
  hello5.clj

?

Attempt:

I know that I can generate the .clj and .cljs files of a directory via

FOUND_FILES=$(find "dir1" -type f -regex ".*\.\(clj\|cljs\)")

and that I can use the basename command to get the basename of a file. How to do the rest?

Answer 1

You can do this with globs and parameter expansion. You don't need to use find if you have a version of bash that has globstar to enable ** syntax (bash4+).

# Enable `**`, and expand globs to 0 elements if unmatched
shopt -s globstar nullglob
# Put all files matching *.clj or *.cljs into ${files[@]} recursively
files=(dir1/**/*.clj{,s})
# Print all files delimited by newlines, with all leading directories stripped
printf '%s\n' "${files[@]##*/}"

To apply some arbitrary transformation, replace the last line with:

for file in "${files[@]}"; do
    some-arbitrary-transformation <<< "$file"
done

Answer 2

shopt -s globstar nullglob
var="$(echo **/*.clj **/*.cljs | xargs -n1 basename)"
echo "$var"