| #!/bin/sh |
| # Copyright 2024 The Fuchsia Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| # Run a generator script, with arguments, collect its output, write it |
| # to a file before sending it to stdout. |
| # |
| # Usage: |
| # <this_script> OUTPUT_FILE GENERATOR_SCRIPT [GENERATOR_ARGS...] |
| # |
| # Where GENERATOR_ARGS may also contain OUTPUT_FILE. |
| |
| set -e |
| |
| die () { |
| echo >&2 "ERROR: $*" |
| return 1 |
| } |
| |
| case $# in |
| 0) die "Missing output file (1st argument)";; |
| 1) die "Missing generator script path (2nd argument)";; |
| *);; |
| esac |
| |
| output_file="$1" |
| shift |
| |
| temp_output_file="${output_file}.tmp" |
| "$@" > "${temp_output_file}" || die "Generator script returned error $?!" |
| |
| |
| update_file= |
| if ! test -f "${output_file}"; then |
| update_file=true |
| elif ! cmp --quiet "${temp_output_file}" "${output_file}"; then |
| update_file=true |
| fi |
| if test -n "${update_file}"; then |
| mv -f "${temp_output_file}" "${output_file}" |
| fi |
| |
| cat "${output_file}" |
