Generation and use of patch files

The patch is generated using the diff tool, and the patch tool is patched.

Before using diff, you need to keep a copy of the unmodified source code and modify the source code elsewhere. diff compares the two source codes to generate a patch. the modified source code must retain the original file name. For example, if you modify. c file. The modified file is still named. c. You can copy. C is. orig. c. Back up data.

The diff command must be executed in the upper-level directory of the root directory of the entire Linux source code.

1. Generate patches for a single file

Diff-up linux-2.6.28.8/NET/SunRPC/svc. orig. c linux-2.6.28.8/NET/SunRPC/svc. c

This command will generate output similar to the following. You can redirect it to a file, which is a patch.

--- Linux-2.6.28.8/NET/SunRPC/svc. orig. c 08:50:04. 000000000 + 0800

++ Linux-2.6.28.8/NET/SunRPC/svc. c 19:18:41. 859375000 + 0800

@-1050,11 + 1050,11 @ svc_process (struct svc_rqst * rqstp)

Parameters:

-U displays the rows (context) before and after the different rows. The default value is three rows before and after the difference. In this way, the patch contains more information.

-P: displays information about the C function of the Code.

2. Generate patches for multiple files

Diff-uprn linux-2.6.28.8.orig/NET/SunRPC/linux-2.6.28.8/NET/SunRPC/

This command compares the source code differences between the linux-2.6.28.8.orig/NET/SunRPC/and the linux-2.6.28.8/NET/SunRPC/directories. unlike a single file, if you modify multiple files, you need to copy the entire Linux source code tree.

Parameters:

-R recursively compares a directory with all its subdirectories (that is, the entire directory tree ).

-N if a file is missing, it is treated as an empty file for comparison. if this option is not used, when diff finds that the old Code or the new Code lacks a file, it simply prompts that the file is missing. if this option is used, the newly added file is printed out as a newly added part.

3. Patch

In the generated patch, the path information contains the name of your Linux source code root directory, but other people's source code root directory may be another name. Therefore, when patching, to enter the root directory of your Linux source code and tell the patch tool, ignore the first directory (parameter-P1) of the path in the patch ).

Patch-p1

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