CMake编译静态库

准备工作

• 安装cmake
  我的系统是ubuntu16，这一步就不赘述了，apt或者源代码安装都没问题。

• 源代码
  我是想在系统中学习好linux应用层编程，所以我买了Linux/Uinx系统编程手册。
  在学习过程中发现他的代码都依赖于作者所写的几个头文件，所以我产生了将其将其编译成静态库的想法，虽然文件不多，但是姑且也算是学习到了一些东西。需要的可以自行百度搜索下载。
  源代码分布如下：
  ```sh
  zqh@linux:~/system_program$ tree .
  .
  ├── build
  ├── CMakeLists.txt
  ├── lib
  │ ├── alt_functions.c
  │ ├── alt_functions.h
  │ ├── CMakeLists.txt
  │ ├── ename.c.inc
  │ ├── error_functions.c
  │ ├── error_functions.h
  │ ├── get_num.c
  │ ├── get_num.h
  │ └── tlpi_hdr.h
  └── 编译静态库.md

  2 directories, 11 files
  ```
• 编写CMakeLists
  • lib目录下的CMakeLists

  CMAKE_MINIMUM_REQUIRED(VERSION 2.8)  
  
  SET(LIB_SRC alt_functions.c error_functions.c get_num.c)  #添加源文件
  
  #添加静态库  
  ADD_LIBRARY(tpli_static STATIC ${LIB_SRC})  
  
  #将静态库重新命名为Libtpli
  SET_TARGET_PROPERTIES(tpli_static PROPERTIES OUTPUT_NAME "tpli")

  • 当前目录下的CMakeLists

  CMAKE_MINIMUM_REQUIRED(VERSION 2.8)  
  PROJECT(TestLIB)  #工程名
  ADD_SUBDIRECTORY(lib) #添加子目录

• 编译
  sh cd build/ cmake .. make
  查看结果
  sh zqh@linux:~/system_program/build$ ls CMakeCache.txt CMakeFiles cmake_install.cmake lib Makefile zqh@linux:~/system_program/build$ cd lib/ zqh@linux:~/system_program/build/lib$ ls CMakeFiles cmake_install.cmake libtpli.a Makefile
  现在生成了静态库libtpli.a。
• 测试

  • 准备
    新建了一个目录test，将头文件加入其中，内容如下
    ```sh
    zqh@linux:~/system_program/test$ tree
    .
    ├── build
    ├── CMakeLists.txt
    ├── inc
    │ ├── alt_functions.h
    │ ├── ename.c.inc
    │ ├── error_functions.h
    │ ├── get_num.h
    │ └── tlpi_hdr.h
    └── test.c

    2 directories, 7 files
    test.c（复制文件内容到另一个文件）:c
    /************************************************************************* * Copyright (C) Michael Kerrisk, 2017. *

    •                                                                     *

    • This program is free software. You may use, modify, and redistribute it *
    • under the terms of the GNU General Public License as published by the *
    • Free Software Foundation, either version 3 or (at your option) any *
    • later version. This program is distributed without any warranty. See *
    • the file COPYING.gpl-v3 for details.
      ************************************************************************/

    /* Listing 4-1 */

    /* copy.c

    Copy the file named argv[1] to a new file named in argv[2].
    */
    #include <sys/stat.h>
    #include <fcntl.h>
    #include "tlpi_hdr.h"

    #ifndef BUF_SIZE /* Allow "cc -D" to override definition */
    #define BUF_SIZE 1024
    #endif

    int
    main(int argc, char *argv[])
    {
    int inputFd, outputFd, openFlags;
    mode_t filePerms;
    ssize_t numRead;
    char buf[BUF_SIZE];

      if (argc != 3 || strcmp(argv[1], "--help") == 0)
          usageErr("%s old-file new-file\n", argv[0]);
    
      /* Open input and output files */
    
      inputFd = open(argv[1], O_RDONLY);
      if (inputFd == -1)
          errExit("opening file %s", argv[1]);
    
      openFlags = O_CREAT | O_WRONLY | O_TRUNC;
      filePerms = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP |
                  S_IROTH | S_IWOTH;      /* rw-rw-rw- */
      outputFd = open(argv[2], openFlags, filePerms);
      if (outputFd == -1)
          errExit("opening file %s", argv[2]);
    
      /* Transfer data until we encounter end of input or an error */
    
      while ((numRead = read(inputFd, buf, BUF_SIZE)) > 0)
          if (write(outputFd, buf, numRead) != numRead)
              fatal("couldn't write whole buffer");
      if (numRead == -1)
          errExit("read");
    
      if (close(inputFd) == -1)
          errExit("close input");
      if (close(outputFd) == -1)
          errExit("close output");
    
      exit(EXIT_SUCCESS);

    }
    CMakeLists.txt:cmake
    CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
    project (Tutorial) #工程名

    # 添加头文件目录
    include_directories(${PROJECT_SOURCE_DIR}/inc )

    link_libraries(/home/zqh/system_program/build/lib/libtpli.a)#添加静态库

    add_executable (Tutorial test.c) #创建可执行文件

    target_link_libraries(Tutorial /home/zqh/system_program/build/lib/libtpli.a)# 连接静态库库
    ```
  • 编译
    sh cd build/ cmake .. make

  • 运行
    sh ./Tutorial Usage: ./Tutorial old-file new-file cat 1.txt 编译静态库成功 ./Tutorial 1.txt 2.txt cat 2.txt 编译静态库成功