Detect multiple tgz files in a directory with shell script

Question

I'm trying to use the following condition to detect *.tgz archives in a directory:

if [ -e ${INPUT_DIRECTORY}*tgz ]

While this condition works great when there is only one file, it's giving me an expected binary operator error on the 'if' line of my script, when there is more than one *.tgz file in the directory.

What am I missing ?

The description of the `-e` option in `man test` suggests that it wasn't intended to be used for multiple files. — Daniel Walker, Nov 05 '21 at 15:33
More information would be helpful, since this smells a bit like an [XY Problem](https://xyproblem.info). Is the lack of tgz files in that directory considered an error? Meaning, do you actually need to detect the **absence** rather than the presence of such files? — Nikos C., Nov 05 '21 at 15:40

Kristian · Answer 1 · 2021-11-05T15:32:41.927

You can just ls it, then check the exit code of ls. If it's 0 then the file exist, otherwise it doesn't.

$ ls wfh.sh
wfh.sh
$ echo $?
0
$ ls a
ls: cannot access 'a': No such file or directory
$ echo $?
2

In your case, you can write:

ls ${INPUT_DIRECTORY}*.tgz > /dev/null 2>&1

if [ $? -eq 0 ] ; then
  echo "exist!"
else
  echo "not!"
fi

Also, you should change your globbing to ${INPUT_DIRECTORY}*.tgz instead of ${INPUT_DIRECTORY}*tgz since it may unintentionally match something like filletgz

For more readable script, you can also write:

if ls ${INPUT_DIRECTORY}*.tgz > /dev/null 2>&1 ; then
  echo "exist!"
else
  echo "not!"
fi

score 0 · Answer 2 · answered Nov 05 '21 at 17:52

Here’s a suggestion for a test, in pure shell:

for i in "$input_dir"/*.tgz "$input_dir"/.*.tgz; do
    test -e "$i" && break
done

This returns success or failure, depending on if .tgz files exist. You can obviously remove the second pattern if you want to ignore hidden files.

As a function/example:

suffix_exists ()
{
    for i in "${2:-.}"/*"$1" "${2:-.}"/.*"$1"; do
        test -e "$i" && return 0
    done
}

if suffix_exists .tgz "$input_dir"; then
    echo "$input_dir contains .tgz archives"
else
    echo "$input_dir does not contain .tgz archives"
fi

It uses the current directory if none is provided.

As mentioned in another answer, you might be approaching your task in the wrong way (perhaps post your objective). Instead of detecting .tgz archives in the directory, you could run a command on any archives that do exist, using find. For example extracting them:

find "$input_dir" -mindepth 1 -maxdepth 1 \
     -type f -name '*.tgz' -exec tar xf {} \;

Or moving them somewhere:

find "$input_dir" -mindepth 1 -maxdepth 1 \
     -type f -name '*.tgz' -exec mv -i {} /my/archives \;

Detect multiple tgz files in a directory with shell script

2 Answers2