使用和制作patch文件

发表时间: 2007-2-13 20:57    作者: superuser    来源: 迷茫人

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原文

今天上QQ的时候发现eva不能用了，后来又看到了解决方法，所以想打个补丁，只是不会:-)。后来查了查明确了，写了个总结，分享一下，也不知道曾经有没有这方面的东西，希望我这个不是多余的。

创建补丁文件：

CODE:

diff -Naur 旧的文件夹 新的文件夹 > patch文件

或者

diff -Naur 旧的文件 新的文件 > patch文件

对于文件夹层数的一些限制

在创建patch的时候文件夹的层数应当是一样的，比方

CODE:

--- old/modules/pcitableMon Sep 27 11:03:56 1999

+++ new/modules/pcitableTue Dec 19 20:05:41 2000

这样是能够的。

而

CODE:

--- old/try1/other/modules/pcitableMon Sep 27 11:03:56 1999

+++ new/modules/pcitableTue Dec 19 20:05:41 2000

这样做可能会有一些问题。

怎样使用patch

对于一个patch文件，有两种经常使用用法：

1.

CODE:

cat new-patch | patch -p02.

2、

CODE:

patch -p0 < new-patch

patch命令里面的层数(-p0?-p1?)

參数-p来指定从第几层開始比較。比方有一个patch文件的补丁头是这种：

CODE:

--- old/modules/pcitableMon Sep 27 11:03:56 1999

+++ new/modules/pcitableTue Dec 19 20:05:41 2000

假设使用參数-p0，就表示从当前文件夹，找一个叫作new的文件夹，在它以下找一个叫modules的文件夹，再在它以下找一个叫pcitableMon的文件夹。

假设使用參数-p1,就表示忽略第一层，从当前文件夹找一个叫modules的文件夹，在它以下找一个叫modules的文件夹。这样会忽略掉补丁头提到的new文件夹。

依此类推。

patch文件的结构

补丁头

补丁头是分别由---/+++开头的两行，用来表示要打补丁的文件。

一个补丁文件里的多个补丁

一个补丁文件里可能包括以---/+++开头的非常多节，每一节用来打一个补丁。所以在一个补丁文件里能够包括好多个补丁。

块

块是补丁中要改动的地方。它通常由一部分不用改动的东西開始和结束。他们仅仅是用来表示要改动的位置。他们通常以@@開始，结束于还有一个块的開始或者一个新的补丁头。

块的缩进

块会缩进一列，而这一列是用来表示这一行是要添加还是要删除的。

块的第一列

+号表示这一行是要加上的。

-号表示这一行是要删除的。

没有加号也没有减号表示这里仅仅是引用的而不须要改动。

一个patch的样例

CODE:

diff -u old/modules/pcitable new/modules/pcitable

--- old/modules/pcitableMon Sep 27 11:03:56 1999

+++ new/modules/pcitableTue Dec 19 20:05:41 2000

@@ -1,4 +1,6 @@

0x0e110xae10"cpqarray""Compaq|Smart-2/P RAID Controller"

+0x10000x0010"cpqarray""Compaq|Integrated Array Controller"

+0x10110x0046"cpqarray""Compaq|Smart-2/P RAID Controller"

0x0e110xae32"tlan""Compaq|Netelligent 10/100"

0x0e110xae34"tlan""Compaq|Netelligent 10"

0x0e110xae35"tlan""Compaq|Integrated NetFlex-3/P"

@@ -21,6 +23,7 @@

0x10000x000f"ncr53c8xx""Symbios|53c875"

0x10000x0012"ncr53c8xx""Symbios|53c895a"

0x10000x008f"ncr53c8xx""Symbios|53c875J"

+0x10000x000a"sym53c8xx""Symbios|53c1510"

0x10000x0701"yellowfin""Symbios|83C885 gigabit ethernet"

0x10000x0702"yellowfin""Symbios|Yellowfin G-NIC gigabit ethernet"

0x10110x0001"tulip""DEC|DECchip 21050"

--- old/usr/share/kudzu/pcitableSun Sep 26 17:11:23 1999

+++ new/usr/share/kudzu/pcitableTue Dec 19 20:05:41 2000

@@ -15,6 +15,8 @@

0x0e110x3034"unknown""Compaq|QVision 1280/p"

0x0e110x4000"unknown""Compaq|4000 [Triflex]"

0x0e110xa0f3"ignore""Compaq|Triflex PCI to ISA Bridge"

+0x10000x0010"cpqarray""Compaq|Integrated Array Controller"

+0x10110x0046"cpqarray""Compaq|Smart-2/P RAID Controller"

0x0e110xae10"cpqarray""Compaq|Smart-2/P RAID Controller"

0x0e110xae29"unknown""Compaq|MIS-L"

0x0e110xae2a"unknown""Compaq|MPC"

@@ -46,6 +48,7 @@

0x10000x000f"ncr53c8xx""Symbios|53c875"

0x10000x0012"ncr53c8xx""Symbios|53c895a"

0x10000x008f"ncr53c8xx""Symbios|53c875J"

+0x10000x000a"sym53c8xx""Symbios|53c1510"

0x10000x0701"yellowfin""Symbios|83C885 gigabit ethernet"

0x10000x0702"yellowfin""Symbios|Yellowfin G-NIC gigabit ethernet"

0x10000x0901"unknown""Symbios|61C102"

分析

这个样例是由命令

CODE:

diff -u old/modules/pcitable new/modules/pcitable

创建的。只是最好是用命令diff -Naur来取代diff -u。

它改动了两个文件，new/modules/pcitable和new/usr/share/kudzu/pcitable。

第一个补丁头包括两个块，分别添加了两行和一行。

这个是參考了这篇文来总结翻译。因为刚刚接触这些东西，非常多地方可能翻译的不恰当，尤其是一些术语，如有发现问题，请给我留言说明，以便我来改正，谢谢。

相关评论

• superuser (2007-2-13 21:12:26)

  Patching (very) Mini Howto

  Introduction

  This very short document is a slightly lengthened version of an email I wrote in 2003 on the subject of patches, I've put it here in case it could be useful to anyone else.

  The Howto

  cd into the directory containing the sources you want to patch:

  CODE:

  $ cd madwifiThen you need to pipe the patch file into the program 'patch', like this:

  CODE:

  $ cat /path/to/patch/patch.diff | patch -p1The processs for applying gzipped or bzipped patches is almost identical, only you use a modified version of 'cat' which can handle the compression thats been used e.g:

  CODE:

  $ bzcat /path/to/patch/patch.bz2 | patch -p1for bzips, or

  CODE:

  $ zcat /path/to/patch/patch.gz2 | patch -p1for the (more common) gzips.

  Another way which might interest some people (which I've just descovered) is to do things the other way around, in this way you can do it without running cat:

  CODE:

  $ patch -p1 < patchI'm not exactly sure how to do this with zipped patches just yet however, my experiments would lead me to belive that its more complex than most of what's above.

  The option -p1 tells the patch program to remove 1 layer of all the filenames from the input, you do this because normally the person who made the patch is one directory closer to / than you. The best way to explain this is too look at the content of a patch (this is part of the wireless extensions patch):

  CODE:

  diff -u -p linux/include/linux/wireless.15.h linux/include/linux/wireless.h

  --- linux/include/linux/wireless.15.h   Fri Jan 10 16:55:07 2003

  +++ linux/include/linux/wireless.h  Wed Apr  2 16:33:31 2003The lines mention "linux/include/[...]", now if you have more than one set of kernel sources on your system, then the one you want to patch will not necessarily be in as directory called 'linux', the -p1 option would strip the linux from the filename and just leave:

  CODE:

  diff -u -p include/linux/wireless.15.h include/linux/wireless.h

  --- include/linux/wireless.15.h   Fri Jan 10 16:55:07 2003

  +++ include/linux/wireless.h  Wed Apr  2 16:33:31 2003From the above discussion, it should be fairly easy to see that patch strips from the left hand side, and removes n slashes. Where n is the number the 'p' option.

  There are a couple of other things which I thinks its handy to know about patch, first is that not all patches will go on 'cleanly', sometimes you will get messages like 'Hunk suceeded at offset 32', this means that that part of the patch applied, but not in the exact same place as the original author intended. This happens all the time with the madwifi driver from cvs.

  Second is the -R swich for 'patch', this:

  CODE:

  $ cat /path/to/patch/patch.diff | patch -p1 -Rwould remove the patch from your current directory tree.

  And finally

  One last thing to remember: I am no expert, and some of this may be a bit wrong, missing something or whatever. Drop me a line if it is.