Test whether a glob has any matches in bash

Bash-specific solution:

compgen -G "<glob-pattern>"

Escape the pattern or it'll get pre-expanded into matches.

Exit status is:

• 1 for no-match,
• 0 for 'one or more matches'

stdout is a list of files matching the glob. I think this is the best option in terms of conciseness and minimizing potential side effects.

Example:

if compgen -G "/tmp/someFiles*" > /dev/null; then
    echo "Some files exist."
fi

The nullglob shell option is indeed a bashism.

To avoid the need for a tedious save and restore of the nullglob state, I'd only set it inside the subshell that expands the glob:

if test -n "$(shopt -s nullglob; echo glob*)"
then
    echo found
else
    echo not found
fi

For better portability and more flexible globbing, use find:

if test -n "$(find . -maxdepth 1 -name 'glob*' -print -quit)"
then
    echo found
else
    echo not found
fi

Explicit -print -quit actions are used for find instead of the default implicit -print action so that find will quit as soon as it finds the first file matching the search criteria. Where lots of files match, this should run much faster than echo glob* or ls glob* and it also avoids the possibility of overstuffing the expanded command line (some shells have a 4K length limit).

If find feels like overkill and the number of files likely to match is small, use stat:

if stat -t glob* >/dev/null 2>&1
then
    echo found
else
    echo not found
fi

I like

exists() {
    [ -e "$1" ]
}

if exists glob*; then
    echo found
else
    echo not found
fi

This is both readable and efficient (unless there are a huge number of files).
The main drawback is that it's much more subtle than it looks, and I sometimes feel compelled to add a long comment.
If there's a match, "glob*" is expanded by the shell and all the matches are passed to exists(), which checks the first one and ignores the rest.
If there's no match, "glob*" is passed to exists() and found not to exist there either.

Edit: there may be a false positive, see comment