diff和patch使用指南(国外英文资料).doc

diff和patch使用指南(国外英文资料) Diff and patch are a pair of tools, mathematically speaking, diff is the difference between two sets, patch is the sum of two sets. Diff compares the differences in the two files or collections of files, and records them to generate a diff file, which is also what we often call the patch file, the patch file. Patch can apply the diff file to one of the original sets, resulting in another set. For example, file A and B, patch file was generated after the diff C, injection process is equivalent to A - B = C, then the process of patch is B + C = A or A - C = B. So all we need to do is get A, B, C, any two of these three files, and we can use diff and patch to generate another file for the tool. Thats the beauty of diff and patch. Heres a look at the usage of the two tools: 1. The use of the diff Diff can be followed by two filenames or two directory names. If it is a directory name and a filename, then only the file name of the same name is applied in that directory. If you have two directories, all the files under this directory will not be recursively. If we want to recurse, we need to use the -r parameter. Command diff A B, C, A is the original file, B is the modified file, C is called A patch file. The diff file format, which is generated without any parameters, is a simple format that only shows different lines and content. We need a more detailed format that identifies the context of the different locations, which is more conducive to improving the ability to recognize the patch command. You can use the -c switch at this time. 2. The use of the patch Patch is used to generate the target file based on the original file and the patch file. Lets take an example Patch A C will get B, which is called the patch of C for A. After that, your file A becomes A file B. What if you want to get back to A after the patch? The patch minus R B C can be restored to A. So dont worry about losing A. Patch is actually used without specifying the original file