reimplementation of moreutils' sponge

sponge

#!/bin/bash

# reimplementation of moreutil's sponge
# moreutil conflicts with GNU parallel on both Ubuntu and Fedora
# http://manned.org/sponge/c673547d

PATH=/bin:/usr/bin

outputfile="$1"

tempfile="$(mktemp)"
[ -f "$tempfile" ] || exit 1

cat > "$tempfile"

if [ -n "$outputfile" ] ; then
    # -> output to file specified
    [ -f "$outputfile" ] && {
        chmod --reference="$outputfile" "$tempfile"
    }
    mv "$tempfile" "$outputfile"
else
    # -> stdout
    cat "$tempfile"
    rm -f "$tempfile"
fi

# EOF