From 9659df52822a2fd7f85725d2ff680871b1f3bdc7 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Thu, 14 Oct 2010 12:53:11 +0200 Subject: [PATCH] Clarify and extend the "git diff" format documentation Move the similarity and dissimilarity index header description closer to where those extended headers are described. Describe and/or clarify the format used for file modes, pathnames, and the index header. Document that all "old" files refer to the state before applying the *entire* output, and all "new" files refer to the state thereafter. Signed-off-by: Andreas Gruenbacher Signed-off-by: Junio C Hamano --- Documentation/diff-generate-patch.txt | 40 ++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 10 deletions(-) diff --git a/Documentation/diff-generate-patch.txt b/Documentation/diff-generate-patch.txt index 8f9a2412fd..3ac2beac62 100644 --- a/Documentation/diff-generate-patch.txt +++ b/Documentation/diff-generate-patch.txt @@ -9,16 +9,15 @@ patch file. You can customize the creation of such patches via the GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables. What the -p option produces is slightly different from the traditional -diff format. +diff format: -1. It is preceded with a "git diff" header, that looks like - this: +1. It is preceded with a "git diff" header that looks like this: diff --git a/file1 b/file2 + The `a/` and `b/` filenames are the same unless rename/copy is involved. Especially, even for a creation or a deletion, -`/dev/null` is _not_ used in place of `a/` or `b/` filenames. +`/dev/null` is _not_ used in place of the `a/` or `b/` filenames. + When rename/copy is involved, `file1` and `file2` show the name of the source file of the rename/copy and the name of @@ -37,18 +36,39 @@ the file that rename/copy produces, respectively. similarity index dissimilarity index index .. - -3. TAB, LF, double quote and backslash characters in pathnames - are represented as `\t`, `\n`, `\"` and `\\`, respectively. - If there is need for such substitution then the whole - pathname is put in double quotes. - ++ +File modes are printed as 6-digit octal numbers including the file type +and file permission bits. ++ +Path names in extended headers do not include the `a/` and `b/` prefixes. ++ The similarity index is the percentage of unchanged lines, and the dissimilarity index is the percentage of changed lines. It is a rounded down integer, followed by a percent sign. The similarity index value of 100% is thus reserved for two equal files, while 100% dissimilarity means that no line from the old file made it into the new one. ++ +The index line includes the SHA-1 checksum before and after the change. +The is included if the file mode does not change; otherwise, +separate lines indicate the old and the new mode. + +3. TAB, LF, double quote and backslash characters in pathnames + are represented as `\t`, `\n`, `\"` and `\\`, respectively. + If there is need for such substitution then the whole + pathname is put in double quotes. + +4. All the `file1` files in the output refer to files before the + commit, and all the `file2` files refer to files after the commit. + It is incorrect to apply each change to each file sequentially. For + example, this patch will swap a and b: + + diff --git a/a b/b + rename from a + rename to b + diff --git a/b b/a + rename from b + rename to a combined diff format -- 2.11.4.GIT