This patch also changes the term "custom diff driver" to "external diff driver"; now that there are more facets of a "custom driver" than just external diffing, it makes sense to refer to the configuration of "diff.foo.*" as the "foo diff driver", with "diff.foo.command" as the "external driver for foo". Signed-off-by: Jeff King <peff@xxxxxxxx> --- Documentation/gitattributes.txt | 66 +++++++++++++++++++++++++++++++-------- 1 files changed, 53 insertions(+), 13 deletions(-) diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt index 2694559..314e2d3 100644 --- a/Documentation/gitattributes.txt +++ b/Documentation/gitattributes.txt @@ -213,10 +213,12 @@ with `crlf`, and then `ident` and fed to `filter`. Generating diff text ~~~~~~~~~~~~~~~~~~~~ -The attribute `diff` affects if 'git-diff' generates textual -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. +The attribute `diff` affects how 'git' generates diffs for particular +files. It can tell git whether to generate a textual patch for the path +or to treat the path as a binary file. It can also affect what line is +shown on the hunk header `@@ -k,l +n,m @@` line, tell git to use an +external command to generate the diff, or ask git to convert binary +files to a text format before generating the diff. Set:: @@ -227,7 +229,8 @@ Set:: Unset:: A path to which the `diff` attribute is unset will - generate `Binary files differ`. + generate `Binary files differ` (or a binary patch, if + binary patches are enabled). Unspecified:: @@ -238,21 +241,21 @@ Unspecified:: 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. This name is also used for custom hunk header - selection. + Diff is shown using the specified diff driver. Each driver may + specify one or more options, as described in the following + section. The options for the diff driver "foo" are defined + by the configuration variables in the "diff.foo" section of the + git config file. -Defining a custom diff driver -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Defining an external diff driver +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The definition of a diff driver is done in `gitconfig`, not `gitattributes` file, so strictly speaking this manual page is a wrong place to talk about it. However... -To define a custom diff driver `jcdiff`, add a section to your +To define an external diff driver `jcdiff`, add a section to your `$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this: ---------------------------------------------------------------- @@ -328,6 +331,43 @@ patterns are available: - `tex` suitable for source code for LaTeX documents. +Performing text diffs of binary files +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Sometimes it is desirable to see the diff of a text-converted +version of some binary files. For example, a word processor +document can be converted to an ASCII text representation, and +the diff of the text shown. Even though this conversion loses +some information, the resulting diff is useful for human +viewing (but cannot be applied directly). + +The `textconv` config option is used to define a program for +performing such a conversion. The program should take a single +argument, the name of a file to convert, and produce the +resulting text on stdout. + +For example, to show the diff of the exif information of a +file instead of the binary information (assuming you have the +exif tool installed): + +------------------------ +[diff "jpg"] + textconv = exif +------------------------ + +NOTE: The text conversion is generally a one-way conversion; +in this example, we lose the actual image contents and focus +just on the text data. This means that diffs generated by +textconv are _not_ suitable for applying. For this reason, +only `git diff` and the `git log` family of commands (i.e., +log, whatchanged, show) will perform text conversion. `git +format-patch` will never generate this output. If you want to +send somebody a text-converted diff of a binary file (e.g., +because it quickly conveys the changes you have made), you +should generate it separately and send it as a comment _in +addition to_ the usual binary diff that you might send. + + Performing a three-way merge ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- 1.6.0.3.518.gdb328.dirty -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
