Add prepare-release.

	修改：     .gitignore
	修改：     m4/readfile.m4
	新文件：   tools/prepare-release

Author: ChenPi11

.gitignore

@@ -18,3 +18,6 @@ config.status
 # Build outputs
 include/libplatform.h
 Makefile
+
+# Dist directory
+libplatform-*

m4/readfile.m4

@@ -1,5 +1,5 @@
 # readfile.m4
-dnl Copyright (C) 2023 ChenPi11.
+dnl Copyright (C) 2023 The C++ Plus Project.
 dnl This file is free software; The C++ Plus Project
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

tools/prepare-release

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+
+# Prepare libplatform release.
+# You need call this script on libplatform root directory.
+
+# The libplatform library is free software; you can redistribute it
+# and/or modify it under the terms of the The Unlicense
+# as published by the unlicense.org.
+# 
+# The libplatform library is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the The
+# Unlicense for more details.
+# 
+# You should have received a copy of the The Unlicense
+# along with the libplatform library; see the file LICENSE.
+# If not, see <https://unlicense.org>.
+
+# Usage: ./prepare-releace [VERSION]
+# 
+
+usage()
+{
+  echo "Usage: $0: [VERSION]"
+  exit 1
+}
+
+if [ "$1" == "" ]
+then
+  usage
+else
+  export VERSION="$1"
+fi
+
+# Check git status
+if [[ $(git status --porcelain) ]]
+then
+  # There are uncommitted changes
+  git clean -fdxn
+  echo "Warning: You need to store uncommitted changes or untracked files, or the release will be unsafe"
+  echo "AND YOU UNTRACKED DATA WILL *LOST FOREVER*!!!!!!!!!!"
+  exit 1
+fi
+
+# Clean repo
+git clean -fdx
+
+# Generate files
+make -f Makefile.devel
+
+# Add project name to version
+export VERSION="libplatform-$VERSION"
+
+# Remove old dist
+rm -rf $VERSION
+
+# Copy files
+mkdir -p $VERSION
+
+for f in $(ls -d * --color=never); do
+  if [ "$f" != "tools" ] && [ "$f" != "$VERSION" ]
+  then
+    echo "Add file or directory: $f"
+    cp -r "$f" $VERSION
+  fi
+done