git/contrib/git-jump

git-jump
========

Git-jump is a script for helping you jump to "interesting" parts of your
project in your editor. It works by outputting a set of interesting
spots in the "quickfix" format, which editors like vim can use as a
queue of places to visit (this feature is usually used to jump to errors
produced by a compiler). For example, given a diff like this:

------------------------------------
diff --git a/foo.c b/foo.c
index a655540..5a59044 100644
--- a/foo.c
+++ b/foo.c
@@ -1,3 +1,3 @@
 int main(void) {
-  printf("hello word!\n");
+  printf("hello world!\n");
 }
-----------------------------------

git-jump will feed this to the editor:

-----------------------------------
foo.c:2: printf("hello word!\n");
-----------------------------------

Obviously this trivial case isn't that interesting; you could just open
`foo.c` yourself. But when you have many changes scattered across a
project, you can use the editor's support to "jump" from point to point.

Git-jump can generate four types of interesting lists:

  1. The beginning of any diff hunks.

  2. The beginning of any merge conflict markers.

  3. Any grep matches.

  4. Any whitespace errors detected by `git diff --check`.


Using git-jump
--------------

To use it, just drop git-jump in your PATH, and then invoke it like
this:

--------------------------------------------------
# jump to changes not yet staged for commit
git jump diff

# jump to changes that are staged for commit; you can give
# arbitrary diff options
git jump diff --cached

# jump to merge conflicts
git jump merge

# jump to all instances of foo_bar
git jump grep foo_bar

# same as above, but case-insensitive; you can give
# arbitrary grep options
git jump grep -i foo_bar
--------------------------------------------------


Related Programs
----------------

You can accomplish some of the same things with individual tools. For
example, you can use `git mergetool` to start vimdiff on each unmerged
file. `git jump merge` is for the vim-wielding luddite who just wants to
jump straight to the conflict text with no fanfare.

As of git v1.7.2, `git grep` knows the `--open-files-in-pager` option,
which does something similar to `git jump grep`. However, it is limited
to positioning the cursor to the correct line in only the first file,
leaving you to locate subsequent hits in that file or other files using
the editor or pager. By contrast, git-jump provides the editor with a
complete list of files and line numbers for each match.


Limitations
-----------

This script was written and tested with vim. Given that the quickfix
format is the same as what gcc produces, I expect emacs users have a
similar feature for iterating through the list, but I know nothing about
how to activate it.

The shell snippets to generate the quickfix lines will almost certainly
choke on filenames with exotic characters (like newlines).