platform_build_soong/scripts/update_out
Sasha Smundak 82b6e8483c A script to update the file contents with the command output.
Used to avoid rerunning Ninja files regeneration if m2rbc conversion
generated the same makefile.

Test: treehugger
Change-Id: I1b0a619f961e6d2c7bf99a48053ecb58147c6db0
2021-11-18 15:15:45 -08:00

21 lines
444 B
Bash
Executable file

#! /bin/bash
# Run given command application and update the contents of a given file.
# Will not change the file if its contents has not changed.
[[ $# -gt 1 ]] || { echo "Usage: ${0##*/} FILE COMMAND" >&2; exit 1; }
set -u
declare -r outfile="$1"
shift
if [[ ! -f $outfile ]]; then
$@ >$outfile
exit
fi
declare -r newout=${outfile}.new
$@ >$newout
rc=$?
if cmp -s $newout $outfile; then
rm $newout
else
mv -f $newout $outfile
fi
exit $rc