sponge - soak up standard input and write to a file (poor mans version)

sponge

#!/usr/bin/env bash
set -euo pipefail
#
# sponge - soak up standard input and write to a file
#

# NOTE: Poor mans versions of sponge
# ... to avoid having to 'apt-get install moreutils' and perl dependencies) in CI pipeline

# Example Usage:
# cat file.txt | grep -v "foobar" | sponge file.txt

target="${1}"
tempfile="/tmp/sponge-$RANDOM-$RANDOM-$RANDOM-$RANDOM-$RANDOM"
cat > $tempfile

chmod --reference="$target" $tempfile
mv -f $tempfile "$target"