From ae7aa49914072b9007ba62245e68b8bbd24f964a Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Sun, 8 Jul 2007 17:15:09 -0700 Subject: [PATCH] Document custom hunk header selection Since the external interface seems to have stabilized for this new feature, let's document it properly. Acked-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- Documentation/gitattributes.txt | 55 ++++++++++++++++++++++++++++++--- 1 file changed, 51 insertions(+), 4 deletions(-) diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt index d3ac9c7181..810df07217 100644 --- a/Documentation/gitattributes.txt +++ b/Documentation/gitattributes.txt @@ -72,8 +72,8 @@ EFFECTS ------- Certain operations by git can be influenced by assigning -particular attributes to a path. Currently, three operations -are attributes-aware. +particular attributes to a path. Currently, the following +operations are attributes-aware. Checking-out and checking-in ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -199,7 +199,9 @@ Generating diff text ~~~~~~~~~~~~~~~~~~~~ The attribute `diff` affects if `git diff` generates textual -patch for the path or just says `Binary files differ`. +patch for the path or just says `Binary files differ`. It also +can affect what line is shown on the hunk header `@@ -k,l +n,m @@` +line. Set:: @@ -224,7 +226,8 @@ String:: Diff is shown using the specified custom diff driver. The driver program is given its input using the same calling convention as used for GIT_EXTERNAL_DIFF - program. + program. This name is also used for custom hunk header + selection. Defining a custom diff driver @@ -249,6 +252,50 @@ parameters, just like `GIT_EXTERNAL_DIFF` program is called. See gitlink:git[7] for details. +Defining a custom hunk-header +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Each group of changes (called "hunk") in the textual diff output +is prefixed with a line of the form: + + @@ -k,l +n,m @@ TEXT + +The text is called 'hunk header', and by default a line that +begins with an alphabet, an underscore or a dollar sign is used, +which matches what GNU `diff -p` output uses. This default +selection however is not suited for some contents, and you can +use customized pattern to make a selection. + +First in .gitattributes, you would assign the `diff` attribute +for paths. + +------------------------ +*.tex diff=tex +------------------------ + +Then, you would define "diff.tex.funcname" configuration to +specify a regular expression that matches a line that you would +want to appear as the hunk header, like this: + +------------------------ +[diff "tex"] + funcname = "^\\(\\\\\\(sub\\)*section{.*\\)$" +------------------------ + +Note. A single level of backslashes are eaten by the +configuration file parser, so you would need to double the +backslashes; the pattern above picks a line that begins with a +backslash, and zero or more occurences of `sub` followed by +`section` followed by open brace, to the end of line. + +There are a few built-in patterns to make this easier, and `tex` +is one of them, so you do not have to write the above in your +configuration file (you still need to enable this with the +attribute mechanism, via `.gitattributes`). Another built-in +pattern is defined for `java` that defines a pattern suitable +for program text in Java language. + + Performing a three-way merge ~~~~~~~~~~~~~~~~~~~~~~~~~~~~