Git – 更新操作
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，他执行了git log命令。
[tom@CentOS ~]$ git clone [email protected]:project.git
上述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
上述命令将产生以下结果 –
commit d1e19d316224cddc437e3ed34ec3c931ad803958 Author: Jerry Mouse <[email protected]> Date: Wed Sep 11 08:05:26 2013 +0530 Changed return type of my_strlen to size_t commit 19ae20683fc460db7d127cf201a1429523b0e319 Author: Tom Cat <[email protected]> Date: Wed Sep 11 07:32:56 2013 +0530 Initial commit
观察日志后，他意识到文件string.c是Jerry添加的，用于实现基本的字符串操作。他对 Jerry 的代码很好奇。于是他在文本编辑器中打开 string.c 并立即发现了一个错误。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
上述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;
}
测试后，他提交更改。
[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
上述命令将产生以下结果 –
commit cea2c000f53ba99508c5959e3e12fff493b Author: Tom Cat <[email protected]> Date: Wed Sep 11 08:32:07 2013 +0530 Changed char pointer to const char pointer commit d1e19d316224cddc437e3ed34ec3c931ad803958 Author: Jerry Mouse <[email protected]> Date: Wed Sep 11 08:05:26 2013 +0530 Changed return type of my_strlen to size_t commit 19ae20683fc460db7d127cf201a1429523b0e319 Author: Tom Cat <[email protected]> Date: Wed Sep 11 07:32:56 2013 +0530 Initial commit
Tom 使用 git push 命令推送他的更改。
[tom@CentOS project]$ git push origin master
上述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 [email protected]:project.git d1e19d3..cea2c00 master −> master
添加新功能
同时，Jerry 决定实现字符串比较功能。于是他修改了string.c。修改后，文件如下所示 –
[jerry@CentOS project]$ git diff
上述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;
}
}
在测试之后，他准备好推动他的改变。
[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
上述命令将产生以下结果 –
commit e944e5aab74b26e7447d3281b225309e4e59efcd Author: Jerry Mouse <[email protected]> Date: Wed Sep 11 08:41:42 2013 +0530 Added my_strcpy function commit d1e19d316224cddc437e3ed34ec3c931ad803958 Author: Jerry Mouse <[email protected]> Date: Wed Sep 11 08:05:26 2013 +0530 Changed return type of my_strlen to size_t commit 19ae20683fc460db7d127cf201a1429523b0e319 Author: Tom Cat <[email protected]> Date: Wed Sep 11 07:32:56 2013 +0530 Initial commit
Jerry 对这些变化很满意，他想推动他的变化。
[jerry@CentOS project]$ git push origin master
上述命令将产生以下结果 –
To [email protected]:project.git ! [rejected] master −> master (non-fast-forward) error: failed to push some refs to '[email protected]: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 推送他的更改。因为 Git 发现远程仓库和 Jerry 的本地仓库不同步。因此，他可能会丢失项目的历史记录。为了避免这种混乱，Git 失败了这个操作。现在，Jerry 必须先更新本地存储库，然后才能推送自己的更改。
获取最新更改
Jerry 执行 git pull 命令以将他的本地存储库与远程存储库同步。
[jerry@CentOS project]$ git pull
上述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
拉操作后，Jerry 检查日志消息并找到 Tom 提交 ID 为cea2c000f53ba99508c5959e3e12fff493ba6f69的提交的详细信息
[jerry@CentOS project]$ git log
上述命令将产生以下结果 –
commit e86f0621c2a3f68190bba633a9fe6c57c94f8e4f Author: Jerry Mouse <[email protected]> Date: Wed Sep 11 08:41:42 2013 +0530 Added my_strcpy function commit cea2c000f53ba99508c5959e3e12fff493ba6f69 Author: Tom Cat <[email protected]> Date: Wed Sep 11 08:32:07 2013 +0530 Changed char pointer to const char pointer commit d1e19d316224cddc437e3ed34ec3c931ad803958 Author: Jerry Mouse <[email protected]> Date: Wed Sep 11 08:05:26 2013 +0530 Changed return type of my_strlen to size_t commit 19ae20683fc460db7d127cf201a1429523b0e319 Author: Tom Cat <[email protected]> Date: Wed Sep 11 07:32:56 2013 +0530 Initial commit
现在，Jerry 的本地存储库与远程存储库完全同步。所以他可以安全地推送他的更改。
[jerry@CentOS project]$ git push origin master
上述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 [email protected]:project.git cea2c00..e86f062 master −> master
