#!/bin/bash####  Copyright (c) 2010 The VP8 project authors. All Rights Reserved.####  Use of this source code is governed by a BSD-style license##  that can be found in the LICENSE file in the root of the source##  tree. An additional intellectual property rights grant can be found##  in the file PATENTS.  All contributing project authors may##  be found in the AUTHORS file in the root of the source tree.##  # gen_example_text.sh self=$0 die_usage() {    echo "Usage: $self <example.txt>"    exit 1} die() {    echo "$@"    exit 1} include_block() {    local on_block    while IFS=$'\n' read -r t_line; do        case "$t_line" in            \~*\ ${block_name})                if [ "x$on_block" == "xyes" ]; then                    return 0;                else                    on_block=yes                fi                ;;            *)                if [ "x$on_block" == "xyes" ]; then                    echo "$t_line"                fi                ;;        esac    done    echo "WARNING: failed to find text for block $block_name" >&2    return 1} txt=$1[ -f "$txt" ] || die_usageread -r template < "$txt"case "$template" in    @TEMPLATE*) template=${txt%/*}/${template##@TEMPLATE } ;;    *) die "Failed to parse template name from '$template'" ;;esac fence="~~~~~~~~~"fence="${fence}${fence}"fence="${fence}${fence}"fence="${fence}${fence}"while IFS=$'\n' read -r line; do    case "$line" in        @TEMPLATE*)            template=${template##@TEMPLATE }            template=${template%.c}.txt            ;;        @DEFAULT)            include_block < "$template"            ;;        ~~~*)            block_name=${line##~* }            [ "$block_name" == "INTRODUCTION" ] || echo "$fence"            ;;        *)  echo "$line"            ;;    esacdone < "$txt" echoecho "Putting It All Together"echo "======================="echo "${fence}"${self%/*}/gen_example_code.sh "${txt}"echo "${fence}"