git 更新操作

  • 修改现有功能

    Tom执行克隆操作并找到一个新文件string.c。他想知道是谁将此文件添加到存储库中以及出于什么目的,因此,他执行git log命令。
    
    [tom@CentOS ~]$ git clone gituser@git.server.com:project.git
    
    上面的命令将产生以下结果。
    
    Initialized empty Git repository in /home/tom/project/.git/
    remote: Counting objects: 6, done.
    remote: Compressing objects: 100% (4/4), done.
    Receiving objects: 100% (6/6), 726 bytes, done.
    remote: Total 6 (delta 0), reused 0 (delta 0)
    
    克隆(clone)操作将在当前工作目录中创建一个新目录。他将目录更改为新创建的目录,并执行git log命令。
    
    [tom@CentOS ~]$ cd project/
    
    [tom@CentOS project]$ git log
    
    上面的命令将产生以下结果:
    
    commit d1e19d316224cddc437e3ed34ec3c931ad803958
    Author: Jerry Mouse <jerry@cainiaoya.com>
    Date: Wed Sep 11 08:05:26 2013 +0530
    
    Changed return type of my_strlen to size_t
    
    
    commit 19ae20683fc460db7d127cf201a1429523b0e319
    Author: Tom Cat <tom@cainiaoya.com>
    Date: Wed Sep 11 07:32:56 2013 +0530
    
    Initial commit
    
    观察日志后,他意识到Jerry添加了文件string.c来实现基本的字符串操作。他对Jerry的代码感到好奇。因此,他在文本编辑器中打开string.c并立即发现一个错误。在my_strlen函数中,Jerry没有使用常量指针。因此,他决定修改Jerry的代码。修改后,代码如下:
    
    [tom@CentOS project]$ git diff
    
    上面的命令将产生以下结果:
    
    diff --git a/string.c b/string.c
    index 7da2992..32489eb 100644
    --- a/string.c
    +++ b/string.c
    @@ -1,8 +1,8 @@
    #include <stdio.h>
    -size_t my_strlen(char *s)
    +size_t my_strlen(const char *s)
    {
       - char *p = s;
       + const char *p = s;
       while (*p)
       ++p;
    }
    
    经过测试后,他提交了更改。
    
    [tom@CentOS project]$ git status -s
    M string.c
    ?? string
    
    [tom@CentOS project]$ git add string.c
    
    [tom@CentOS project]$ git commit -m 'Changed char pointer to const char pointer'
    [master cea2c00] Changed char pointer to const char pointer
    1 files changed, 2 insertions(+), 2 deletions(-)
    
    [tom@CentOS project]$ git log
    
    上面的命令将产生以下结果-
    
    commit cea2c000f53ba99508c5959e3e12fff493b
    Author: Tom Cat <tom@cainiaoya.com>
    Date: Wed Sep 11 08:32:07 2013 +0530
    
    Changed char pointer to const char pointer
    
    
    commit d1e19d316224cddc437e3ed34ec3c931ad803958
    Author: Jerry Mouse <jerry@cainiaoya.com>
    Date: Wed Sep 11 08:05:26 2013 +0530
    
    Changed return type of my_strlen to size_t
    
    
    commit 19ae20683fc460db7d127cf201a1429523b0e319
    Author: Tom Cat <tom@cainiaoya.com>
    Date: Wed Sep 11 07:32:56 2013 +0530
    Initial commit
    
    Tom使用git push命令来推送他的更改。
    
    [tom@CentOS project]$ git push origin master
    
    上面的命令将产生以下结果-
    
    Counting objects: 5, done.
    Compressing objects: 100% (3/3), done.
    Writing objects: 100% (3/3), 336 bytes, done.
    Total 3 (delta 1), reused 0 (delta 0)
    To gituser@git.server.com:project.git
    d1e19d3..cea2c00 master −> master
    
  • 新增功能

    同时,Jerry决定实现字符串比较功能。因此,他修改了string.c。修改后,文件如下所示:
    
    [jerry@CentOS project]$ git diff
    
    上面的命令将产生以下结果-
    
    index 7da2992..bc864ed 100644
    --- a/string.c
    +++ b/string.c
    30Git Tutorials
    @@ -9,9 +9,20 @@ size_t my_strlen(char *s)
    return (p -s );
    }
    +char *my_strcpy(char *t, char *s)
    +
    {
       +
       char *p = t;
       +
       + while (*t++ = *s++)
       + ;
       +
       +
       return p;
       +
    }
    +
    int main(void)
    {
       int i; 
       +
       char p1[32];
       char *s[] = 
       {
          "Git tutorials",
          "Tutorials Point"
          @@ -20,5 +31,7 @@ int main(void)
          for (i = 0; i < 2; ++i)
          printf("string lenght of %s = %lu\n", s[i], my_strlen(s[i]));
          +
          printf("%s\n", my_strcpy(p1, "Hello, World !!!"));
          +
          return 0;
       }
    }
    
    经过测试后,他准备推送自己的改变。
    
    [jerry@CentOS project]$ git status -s
    M string.c
    ?? string
    
    [jerry@CentOS project]$ git add string.c
    
    [jerry@CentOS project]$ git commit -m "Added my_strcpy function"
    [master e944e5a] Added my_strcpy function
    1 files changed, 13 insertions(+), 0 deletions(-)
    
    在进行推送操作之前,他通过查看日志消息来验证提交。
    
    [jerry@CentOS project]$ git log
    
    上面的命令将产生以下结果-
    
    commit e944e5aab74b26e7447d3281b225309e4e59efcd
    Author: Jerry Mouse <jerry@cainiaoya.com>
    Date: Wed Sep 11 08:41:42 2013 +0530
    
    Added my_strcpy function
    
    
    commit d1e19d316224cddc437e3ed34ec3c931ad803958
    Author: Jerry Mouse <jerry@cainiaoya.com>
    Date: Wed Sep 11 08:05:26 2013 +0530
    
    Changed return type of my_strlen to size_t
    
    
    commit 19ae20683fc460db7d127cf201a1429523b0e319
    Author: Tom Cat <tom@cainiaoya.com>
    Date: Wed Sep 11 07:32:56 2013 +0530
    
    Initial commit
    
    Jerry对这些变化感到满意,他想推动自己的变化。
    
    [jerry@CentOS project]$ git push origin master
    
    上面的命令将产生以下结果-
    
    To gituser@git.server.com:project.git
    ! [rejected]
    master −> master (non-fast-forward)
    error: failed to push some refs to 'gituser@git.server.com:project.git'
    To prevent you from losing history, non-fast-forward updates were rejected
    Merge the remote changes before pushing again. See the 'Note about
    fast-forwards' section of 'git push --help' for details.
    
    但是Git不允许Jerry推动他的改变。因为Git确定远程存储库和Jerry的本地存储库不同步。因此,他可能会丢失该项目的历史。为了避免这种混乱,Git使该操作失败。现在,Jerry必须先更新本地存储库,然后才能更新自己的更改。
  • 获取最新更改

    Jerry执行git pull命令以将其本地存储库与远程存储库同步。
    
    [jerry@CentOS project]$ git pull
    
    上面的命令将产生以下结果-
    
    remote: Counting objects: 5, done.
    remote: Compressing objects: 100% (3/3), done.
    remote: Total 3 (delta 1), reused 0 (delta 0)
    Unpacking objects: 100% (3/3), done.
    From git.server.com:project
    d1e19d3..cea2c00 master −> origin/master
    First, rewinding head to replay your work on top of it...
    Applying: Added my_strcpy function
    
    pull操作后,Jerry检查日志消息并找到具有提交ID cea2c000f53ba99508c5959e3e12fff493ba6f69的Tom提交的详细信息
    
    [jerry@CentOS project]$ git log
    
    上面的命令将产生以下结果-
    
    commit e86f0621c2a3f68190bba633a9fe6c57c94f8e4f
    Author: Jerry Mouse <jerry@cainiaoya.com>
    Date: Wed Sep 11 08:41:42 2013 +0530
    
    Added my_strcpy function
    
    
    commit cea2c000f53ba99508c5959e3e12fff493ba6f69
    Author: Tom Cat <tom@cainiaoya.com>
    Date: Wed Sep 11 08:32:07 2013 +0530
    
    Changed char pointer to const char pointer
    
    
    commit d1e19d316224cddc437e3ed34ec3c931ad803958
    Author: Jerry Mouse <jerry@cainiaoya.com>
    Date: Wed Sep 11 08:05:26 2013 +0530
    
    Changed return type of my_strlen to size_t
    
    
    commit 19ae20683fc460db7d127cf201a1429523b0e319
    Author: Tom Cat <tom@cainiaoya.com>
    Date: Wed Sep 11 07:32:56 2013 +0530
    Initial commit
    
    现在,Jerry的本地存储库已与远程存储库完全同步。这样他就可以安全地推动自己的更改。
    
    [jerry@CentOS project]$ git push origin master
    
    上面的命令将产生以下结果-
    
    Counting objects: 5, done.
    Compressing objects: 100% (3/3), done.
    Writing objects: 100% (3/3), 455 bytes, done.
    Total 3 (delta 1), reused 0 (delta 0)
    To gituser@git.server.com:project.git
    cea2c00..e86f062 master −> master