Can I make 'git diff' only the line numbers AND changed file names?

So easy:

git diff --name-only

Go forth and diff!

Line numbers as in number of changed lines or the actual line numbers containing the changes? If you want the number of changed lines, use git diff --stat. This gives you a display like this:

[me@somehost:~/newsite:master]> git diff --stat
 whatever/views/gallery.py |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

There is no option to get the line numbers of the changes themselves.

Note: if you're just looking for the names of changed files (without the line numbers for lines that were changed), that's easy, click this link to another answer here.

---

There's no built-in option for this (and I don't think it's all that useful either), but it is possible to do this in git, with the help of an "external diff" script.

Here's a pretty crappy one; it will be up to you to fix up the output the way you would like it.

#! /bin/sh
#
# run this with:
#    GIT_EXTERNAL_DIFF=<name of script> git diff ...
#
case $# in
1) "unmerged file $@, can't show you line numbers"; exit 1;;
7) ;;
*) echo "I don't know what to do, help!"; exit 1;;
esac

path=$1
old_file=$2
old_hex=$3
old_mode=$4
new_file=$5
new_hex=$6
new_mode=$7

printf '%s: ' $path
diff $old_file $new_file | grep -v '^[<>-]'

For details on "external diff" see the description of GIT_EXTERNAL_DIFF in the git manual page (around line 700, pretty close to the end).