Create temporary files in the temporary directory.
Coreutils: https://www.gnu.org/software/coreutils/manual/html_node/mktemp-invocation.html
Creates a temporary file in /tmp/:
f="$(mktemp)"
echo "$f"
assert test -f "$f"
rm "$f"
Directory:
d="$(mktemp -d)"
echo "$f"
assert test -d "$d"
rm -r "$d"
Custom name template:
f="$(mktemp --tmpdir abcXXXdef)"
assert echo "$f" | grep -E 'abc...def'
assert test -f "$f"
rm "$f"
Must use --tmpdir with template or else file is created in current dir.