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Diffstat (limited to 'Documentation/gitattributes.txt')
| -rw-r--r-- | Documentation/gitattributes.txt | 56 |
1 files changed, 45 insertions, 11 deletions
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt index 15aebc6062..2bbe76b5d8 100644 --- a/Documentation/gitattributes.txt +++ b/Documentation/gitattributes.txt @@ -79,7 +79,7 @@ Attributes for all users on a system should be placed in the `$(prefix)/etc/gitattributes` file. Sometimes you would need to override an setting of an attribute -for a path to `unspecified` state. This can be done by listing +for a path to `Unspecified` state. This can be done by listing the name of the attribute prefixed with an exclamation point `!`. @@ -593,6 +593,37 @@ and now produces better output), you can remove the cache manually with `git update-ref -d refs/notes/textconv/jpg` (where "jpg" is the name of the diff driver, as in the example above). +Choosing textconv versus external diff +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +If you want to show differences between binary or specially-formatted +blobs in your repository, you can choose to use either an external diff +command, or to use textconv to convert them to a diff-able text format. +Which method you choose depends on your exact situation. + +The advantage of using an external diff command is flexibility. You are +not bound to find line-oriented changes, nor is it necessary for the +output to resemble unified diff. You are free to locate and report +changes in the most appropriate way for your data format. + +A textconv, by comparison, is much more limiting. You provide a +transformation of the data into a line-oriented text format, and git +uses its regular diff tools to generate the output. There are several +advantages to choosing this method: + +1. Ease of use. It is often much simpler to write a binary to text + transformation than it is to perform your own diff. In many cases, + existing programs can be used as textconv filters (e.g., exif, + odt2txt). + +2. Git diff features. By performing only the transformation step + yourself, you can still utilize many of git's diff features, + including colorization, word-diff, and combined diffs for merges. + +3. Caching. Textconv caching can speed up repeated diffs, such as those + you might trigger by running `git log -p`. + + Marking files as binary ^^^^^^^^^^^^^^^^^^^^^^^ @@ -837,7 +868,7 @@ If this attribute is not set or has an invalid value, the value of the (See linkgit:git-config[1]). -USING ATTRIBUTE MACROS +USING MACRO ATTRIBUTES ---------------------- You do not want any end-of-line conversions applied to, nor textual diffs @@ -848,24 +879,27 @@ produced for, any binary file you track. You would need to specify e.g. ------------ but that may become cumbersome, when you have many attributes. Using -attribute macros, you can specify groups of attributes set or unset at -the same time. The system knows a built-in attribute macro, `binary`: +macro attributes, you can define an attribute that, when set, also +sets or unsets a number of other attributes at the same time. The +system knows a built-in macro attribute, `binary`: ------------ *.jpg binary ------------ -which is equivalent to the above. Note that the attribute macros can only -be "Set" (see the above example that sets "binary" macro as if it were an -ordinary attribute --- setting it in turn unsets "text" and "diff"). +Setting the "binary" attribute also unsets the "text" and "diff" +attributes as above. Note that macro attributes can only be "Set", +though setting one might have the effect of setting or unsetting other +attributes or even returning other attributes to the "Unspecified" +state. -DEFINING ATTRIBUTE MACROS +DEFINING MACRO ATTRIBUTES ------------------------- -Custom attribute macros can be defined only in the `.gitattributes` file -at the toplevel (i.e. not in any subdirectory). The built-in attribute -macro "binary" is equivalent to: +Custom macro attributes can be defined only in the `.gitattributes` +file at the toplevel (i.e. not in any subdirectory). The built-in +macro attribute "binary" is equivalent to: ------------ [attr]binary -diff -text |