feat(scripts): add initool-overwrite.* scripts

Author: dbohdan

README.md

@@ -57,8 +57,12 @@ If the filename is `-`, initool reads standard input. For the commands `get`, `s
 For `exists`, it reports whether the section or the property exists through its exit status.
 
 **Initool never modifies the input file.**
-(One exception is if you redirect initool's output to the same file as input, which results in an empty file
-[like with other programs](https://superuser.com/questions/597244/why-does-redirecting-the-output-of-a-file-to-itself-produce-a-blank-file).)
+One exception is if you redirect initool's output to the same file as input, which results in an empty file
+[like with other programs](https://superuser.com/questions/597244/why-does-redirecting-the-output-of-a-file-to-itself-produce-a-blank-file).
+Two wrapper scripts are included if you want to modify the input file:
+[`initool-overwrite.sh`](initool-overwrite.sh) (POSIX shell)
+and [`initool-overwrite.cmd`](initool-overwrite.cmd) (Windows batch).
+The scripts redirect the output of initool to a temporary file, then overwrite the original.
 
 An INI file consists of properties (`key=value` lines) and sections (designated with a `[section name]` header line).
 A property can be at the "top level" of the file (before any section headers) or in a section (after a section header).

initool-overwrite.cmd

@@ -0,0 +1,65 @@
+@echo off
+setlocal enabledelayedexpansion
+
+for %%a in (%*) do (
+    if "%%a"=="-h" (
+        goto :help
+    )
+    if "%%a"=="--help" (
+        goto :help
+    )
+)
+
+if "%~2"=="" (
+    goto :error_usage
+)
+
+set "command=%~1"
+set "file=%~2"
+set status=0
+set overwrite=1
+
+if "%command%"=="e" (
+    set overwrite=0
+)
+if "%command%"=="exists" (
+    set overwrite=0
+)
+
+if "%file%"=="-" (
+    echo file must not be "-" 1>&2
+    exit /b 2
+)
+
+:create_temp
+set "temp=%temp%\initool-in-place-%random%.tmp"
+if exist "!temp!" goto :create_temp
+
+if defined INITOOL (
+    "!INITOOL!" %* > "!temp!"
+) else (
+    initool %* > "!temp!"
+)
+
+set status=%errorlevel%
+if %status% equ 0 (
+    if %overwrite% equ 1 (
+        copy /y "!temp!" "%file%" > nul
+    )
+)
+
+:cleanup
+del "%temp%"
+exit /b %status%
+
+:error_usage
+echo usage: %~nx0 command file [arg ...] 1>&2
+exit /b 2
+
+:help
+echo Modify the input file with initool.
+echo.
+echo usage: %~nx0 command file [arg ...]
+echo.
+echo You can give the path to initool in the environment variable "INITOOL".
+exit /b

initool-overwrite.sh

@@ -0,0 +1,52 @@
+#! /bin/sh
+set -eu
+
+usage() {
+    echo "usage: $(basename "$0") command file [arg ...]"
+}
+
+help() {
+    printf 'Modify the input file with initool.\n\n'
+    usage
+    printf '\nYou can give the path to initool in the environment variable "INITOOL".\n'
+}
+
+for arg in "$@"; do
+    if [ "$arg" = "-h" ] || [ "$arg" = "--help" ]; then
+        help
+        exit 0
+    fi
+done
+
+if [ $# -lt 2 ]; then
+    usage >/dev/stderr
+    exit 2
+fi
+
+command=$1
+file=$2
+replace_original=1
+
+if [ "$command" = e ] || [ "$command" = exists ]; then
+    replace_original=0
+fi
+
+if [ "$file" = - ]; then
+    echo 'file must not be "-"' >/dev/stderr
+    exit 2
+fi
+
+temp=$(mktemp)
+clean_up() {
+    rm "$temp" 2>/dev/null || true
+}
+trap clean_up EXIT HUP INT QUIT TERM
+
+"${INITOOL:-initool}" "$@" >"$temp"
+status=$?
+
+if [ "$status" -eq 0 ] && [ "$replace_original" -eq 1 ]; then
+    mv "$temp" "$file"
+else
+    exit "$status"
+fi