clear multiple directories with rm

Question

I am trying to clear multiple directories stored in an array. Here's a simplified example (I have more directories).

#!/bin/bash    

$IMAGES_DIR="/Users/michael/scripts/imagefiles"
$BACKUP_DIR="/Users/michael/scripts/imagebackups"

...

array=( $IMAGES_DIR $BACKUP_DIR )
for i in ${array[@]}
do
    if [ "$(ls -A $i)" ]; then     # check that directory has files in it
        rm "$i/"*                  # remove them 
    fi
done

I get errors for each directory, e.g.:

rm: /Users/michael/scripts/imagefiles/*: No such file or directory

Solution

How about accomplishing it all in a single command?

You can capture the file existence check, globbing and removal with one find call. In the case of GNU's version of find we'd have this:

for f in "${array[@]}"; do
     find "$f" -type f -delete
done

If you don't have GNU find use this invocation:

find "$f" -type f -exec rm -f {} +

(If instead of clearing files from the entire directory hierarchy you only want to clear files that are immediate children then add -maxdepth 1 before -type f.)

But wait, there's more....

As John1024 wisely notes you can forgo the loop altogether by passing the array as the first parameter to find:

     find "${array[@]}" -type f -delete

That's because: 1) find will accept multiple directories to be searched and processed in one execution 2) the shell will split the array such that each element (directory) becomes an individual positional parameter to find.

Comments

[John1024]

Simpler: find "${array[@]}" -type f -delete

[B Layer]

Good one @John1024 ... I shoulda thought of that.

[smw]

See Why you shouldn't parse the output of ls(1)

[Praveen Kumar BS]

@steeldriver As cross verified from above command I am getting the same result let me know if there is any difference in output

[Kusalananda]

Note that using the expansion of array would split it on whitespaces as well as expand any other shell globbing characters in the pathname (apart from the * that you add to the end).

[Kusalananda]

This would fail on any file whose name contains whitespace or backslashes. Also, since you're removing files (not directories), why are you using -r with rm?