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2015
10-18

SVN更新过程

Jerry 提交第一个版本的代码。但他认为,他应该写两个函数接受输入和显示阵列的内容。修改后array.c 的样子。

#include <stdio.h>

#define MAX 16

void accept_input(int *arr, int n)
{
   int i;

   for (i = 0; i < n; ++i)
      scanf("%d", &arr[i]);
}

void display(int *arr, int n)
{
   int i;

   for (i = 0; i < n; ++i)
      printf("|%d| ", arr[i]);
   
   printf("
");
}

int main(void)
{
   int i, n, arr[MAX];

   printf("Enter the total number of elements: ");
   scanf("%d", &n);

   printf("Enter the elements
");
   accept_input(arr, n);

   printf("Array has following elements
");
   display(arr, n);

   return 0;
}

Jerry 编译和测试自己的代码,并准备提交修改。在此之前,他希望使用以下命令查看更改。

[jerry@CentOS trunk]$ svn diff

上面的命令将产生以下结果

Index: array.c
===================================================================
--- array.c   (revision 2)
+++ array.c   (working copy)
@@ -2,6 +2,24 @@
 
 #define MAX 16
 
+void accept_input(int *arr, int n)
+{
+   int i;
+
+   for (i = 0; i & n; ++i)
+      scanf("%d", &arr[i]);
+}
+
+void display(int *arr, int n)
+{
+   int i;
+
+   for (i = 0; i < n; ++i)
+      printf("|%d| ", arr[i]);
+   
+   printf("
");
+}
+
 int main(void)
 {
    int i, n, arr[MAX];
@@ -10,15 +28,10 @@
    scanf("%d", &n);
 
    printf("Enter the elements
");
+   accept_input(arr, n);
 
-   for (i = 0; i < n; ++i)
-      scanf("%d", &arr[i]);
-
    printf("Array has following elements
");
-   for (i = 0; i < n; ++i)
-      printf("|%d| ", arr[i]);
-   
-   printf("
");
+   display(arr, n);
 
    return 0;
 }

对于新添加的行颠覆显示+符号, - 符号前行为删除行的显示。Jerry 尝试提交更改,使用下面的命令:

[jerry@CentOS trunk]$ svn commit -m "Add function to accept input and to display array contents"

上面的命令将产生以下结果

Sending        trunk/array.c
svn: Commit failed (details follow):
svn: File or directory 'array.c' is out of date; try updating
svn: resource out of date; try updating

Subversion是不允许Jerry 提交的变化,因为Tome已经修改了库和Jerry的工作拷贝是过时了。为了避免覆盖对方的变化颠覆这个操作失败。Jerry必须更新的工作副本之前提交自己的修改。于是,他用update命令

[jerry@CentOS trunk]$ svn update
G    array.c
Updated to revision 3.

Subversion 显示文件名前G 字母,这意味着此文件已被合并。

[jerry@CentOS trunk]$ svn diff

上面的命令将产生以下结果

Index: array.c
===================================================================
--- array.c   (revision 3)
+++ array.c   (working copy)
@@ -2,6 +2,24 @@
 
 #define MAX 16
 
+void accept_input(int *arr, int n)
+{
+   int i;
+
+   for (i = 0; i < n; ++i)
+      scanf("%d", &arr[i]);
+}
+
+void display(int *arr, int n)
+{
+   int i;
+
+   for (i = 0; i < n; ++i)
+      printf("|%d| ", arr[i]);
+   
+   printf("
");
+}

+
 int main(void)
 {
    int i, n, arr[MAX];
@@ -15,15 +33,10 @@
    }
 
    printf("Enter the elements
");
+   accept_input(arr, n);
 
-   for (i = 0; i < n; ++i)
-      scanf("%d", &arr[i]);
-
    printf("Array has following elements
");
-   for (i = 0; i < n; ++i)
-      printf("|%d| ", arr[i]);
-   
-   printf("
");
+   display(arr, n);
 
    return 0;
 }

Subversion是只显示Jerry 的变化。但array.c的文件合并,如果观察仔细Subversion的现在修订号为3,在以前的输出显示修订号为2。只要审查文件中的变化和目的是什么。

jerry@CentOS trunk]$ svn log
------------------------------------------------------------------------
r3 | tom | 2013-08-18 20:21:50 +0530 (Sun, 18 Aug 2013) | 1 line

Fix array overflow problem
------------------------------------------------------------------------
r2 | jerry | 2013-08-17 20:40:43 +0530 (Sat, 17 Aug 2013) | 1 line

Initial commit
------------------------------------------------------------------------
r1 | jerry | 2013-08-04 23:43:08 +0530 (Sun, 04 Aug 2013) | 1 line

Create trunk, branches, tags directory structure
------------------------------------------------------------------------

现在,Jerry's 工作副本与存储库同步,他可以放心地提交他的变化。

[jerry@CentOS trunk]$ svn commit -m "Add function to accept input and to display array contents"
Sending        trunk/array.c
Transmitting file data .
Committed revision 4.

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