TutorialsArena

Reviewing Changes in Git: A Comprehensive Guide

Learn how to inspect and review changes made to a Git repository. This guide will cover various methods, including using the git diff and git show commands, to understand the differences between commits.

Git - Review Changes

After reviewing the commit details, Jerry realizes that the string length should never be negative. Therefore, he decides to change the return type of the my_strlen function.

Viewing Commit Details

To check the commit history, Jerry uses the git log command:

Syntax

[jerry@CentOS project]$ git log
Output

commit cbe1249b140dad24b2c35b15cc7e26a6f02d2277
Author: Jerry Mouse <jerry@tutorialsarena.com>
Date: Wed Sep 11 08:05:26 2013 +0530

    Implemented my_strlen function

Next, Jerry uses the git show command to view the details of the specific commit. The command takes the SHA-1 commit ID as a parameter:

Syntax

[jerry@CentOS project]$ git show cbe1249b140dad24b2c35b15cc7e26a6f02d2277
Output

commit cbe1249b140dad24b2c35b15cc7e26a6f02d2277
Author: Jerry Mouse <jerry@tutorialsarena.com>
Date: Wed Sep 11 08:05:26 2013 +0530

    Implemented my_strlen function

diff --git a/string.c b/string.c
new file mode 100644
index 0000000..187afb9
--- /dev/null
+++ b/string.c
@@ -0,0 +1,24 @@
+#include <stdio.h>

+int my_strlen(char *s)
+{
+   char *p = s;
+
+   while (*p)
+      ++p;
+
+   return (p - s);
+}
+

After viewing the commit details, Jerry changes the return type of the my_strlen function from int to size_t. After testing his code, he reviews his changes by running the git diff command:

Syntax

[jerry@CentOS project]$ git diff
Output

diff --git a/string.c b/string.c
index 187afb9..7da2992 100644
--- a/string.c
+++ b/string.c
@@ -1,6 +1,6 @@
#include <stdio.h>

-int my_strlen(char *s)
+size_t my_strlen(char *s)
{
   char *p = s;
   @@ -18,7 +18,7 @@ int main(void)
};
for (i = 0; i < 2; ++i)
{
   - printf("string length of %s = %d\\n", s[i], my_strlen(s[i]));
   + printf("string length of %s = %lu\\n", s[i], my_strlen(s[i]));
   return 0;
}

The output from the git diff command shows a + sign before newly added lines and a − sign before deleted lines.