| Sasha Smundak | 82b6e84 | 2021-11-17 17:07:44 -0800 | [diff] [blame] | 1 | #! /bin/bash |
| 2 | # Run given command application and update the contents of a given file. |
| 3 | # Will not change the file if its contents has not changed. |
| 4 | [[ $# -gt 1 ]] || { echo "Usage: ${0##*/} FILE COMMAND" >&2; exit 1; } |
| 5 | set -u |
| 6 | declare -r outfile="$1" |
| 7 | shift |
| 8 | if [[ ! -f $outfile ]]; then |
| 9 | $@ >$outfile |
| 10 | exit |
| 11 | fi |
| 12 | |
| 13 | declare -r newout=${outfile}.new |
| 14 | $@ >$newout |
| 15 | rc=$? |
| 16 | if cmp -s $newout $outfile; then |
| 17 | rm $newout |
| 18 | else |
| 19 | mv -f $newout $outfile |
| 20 | fi |
| 21 | exit $rc |