linux下protobuf 下载并cmake编译安装全过程脚本

protobuf源码下载

github上下载最新版本的protobuf源码zip包，并解压缩到本地
fetch_protobuf.sh

#!/bin/bashshell_folder=$(cd "$(dirname "$0")";pwd)pushd $shell_folder#如果指定的文件/文件夹存在则删除，删除失败则中止脚本remove_if_exist(){    if [ $# -eq 1 ]    then        if [ -e $1 ]        then            rm $1 -fr            if [ ! $? -eq 0 ]            then                exit -1            fi        fi        return 0    else         echo invalid argument:        echo $*        exit -1    fi}exit_on_error(){  if [ ! $? -eq 0 ]  then    exit -1  fi}# 如果文件存在且checksum与$2指定的md5相等则返回 1,否则返回0# $1 待检查的文件路径# $2 md5校验码need_download(){  if [ $# -eq 2 ]    then      if [ -f $1 ]; then        echo "File already exists. Checking md5..."        os=`uname -s`        if [ "$os" = "Linux" ]; then          checksum=`md5sum $1 | awk '{ print $1 }'`        elif [ "$os" = "Darwin" ]; then          checksum=`cat $1 | md5`        fi        if [ "$checksum" = "$2" ]; then          echo "Checksum is correct. No need to download $1."          return 1        else          echo "Checksum is incorrect. Need to download again $1"                        fi    else      return 0    fi  else     echo invalid argument:    echo $*    exit -1  fi}# 从github上下载源码,如果本地不存在指定的zip包，或md5校验码不匹配则从github下载# $1 项目名称# $2 版本号# $3 zip文件的md5# $4 项目所有者名称# $5 zip包文件名前缀download_from_github(){  if [ $# -eq 5 ]  then    project_folder="$1-$2"    project_package="$project_folder.zip"    if need_download $project_package $3    then      echo "(下载源码)downloading $1 $2 source"      wget --no-check-certificate https://github.com/$4/$1/archive/$5$2.zip -O $project_package      exit_on_error    fi    remove_if_exist $project_folder    unzip $project_package    exit_on_error  else    echo invalid argument:    echo $*    exit -1  fi}download_from_github "protobuf" "3.3.1" "9377e414994fa6165ecb58a41cca3b40" "google" "v"popd

protobuf编译安装

对下载的protobuf源码编译并安装到release/protobuf_linux_x86_64文件夹下
build_protobuf.sh

#!/bin/bashGXX_PATH="-DCMAKE_BUILD_TYPE:STRING=RELEASE"INSTALL_FOLDER=$(dirname $(readlink -f $0))/release/protobuf_linux_x86_64pushd protobuf-3.3.1echo INSTALL_FOLDER:$INSTALL_FOLDERif [ -d build.gcc ]then     rm -fr build.gcc/*else     mkdir build.gccfipushd build.gcccmake ../cmake $GXX_PATH -G "Unix Makefiles" -DCMAKE_INSTALL_PREFIX=$INSTALL_FOLDER  -Dprotobuf_BUILD_TESTS=off# 编译并安装protobuf到指定的文件夹make installpopdrm -fr build.gccpopd

上面的脚本中在调用cmake生成Makefile时定义了protobuf_BUILD_TESTS=off,这是因为protobuf的CMakeLists.txt中默认定义protobuf_BUILD_TESTS=on，
而当protobuf_BUILD_TESTS=on时，需要gmock支持(https://github.com/google/googlemock),否则cmake会报如下错误：

CMake Error at tests.cmake:2 (message):
Cannot find gmock directory.

gmock是google公司推出的一款开源的白盒测试工具，对于我们一般的应用来说，不需要gmock提供的功能，所以这里可以将protobuf_BUILD_TESTS=off，避免麻烦。