Retrieve the commit log for a specific line in a file?

Try using below command implemented in Git 1.8.4.

git log -u -L <upperLimit>,<lowerLimit>:<path_to_filename>

So, in your case upperLimit & lowerLimit is the touched line_number

More information can be found here.

See also Git: discover which commits ever touched a range of lines.

---

Since Git 1.8.4, git log has -L to view the evolution of a range of lines.

For example, suppose you look at git blame's output. Here -L 150,+11 means "only look at the lines 150 to 150+11":

$ git blame -L 150,+11 -- git-web--browse.sh
a180055a git-web--browse.sh (Giuseppe Bilotta 2010-12-03 17:47:36 +0100 150)            die "The browser $browser is not
a180055a git-web--browse.sh (Giuseppe Bilotta 2010-12-03 17:47:36 +0100 151)    fi
5d6491c7 git-browse-help.sh (Christian Couder 2007-12-02 06:07:55 +0100 152) fi
5d6491c7 git-browse-help.sh (Christian Couder 2007-12-02 06:07:55 +0100 153) 
5d6491c7 git-browse-help.sh (Christian Couder 2007-12-02 06:07:55 +0100 154) case "$browser" in
81f42f11 git-web--browse.sh (Giuseppe Bilotta 2010-12-03 17:47:38 +0100 155) firefox|iceweasel|seamonkey|iceape)
5d6491c7 git-browse-help.sh (Christian Couder 2007-12-02 06:07:55 +0100 156)    # Check version because firefox < 2.0 do
5d6491c7 git-browse-help.sh (Christian Couder 2007-12-02 06:07:55 +0100 157)    vers=$(expr "$($browser_path -version)" 
5d6491c7 git-browse-help.sh (Christian Couder 2007-12-02 06:07:55 +0100 158)    NEWTAB='-new-tab'
5d6491c7 git-browse-help.sh (Christian Couder 2007-12-02 06:07:55 +0100 159)    test "$vers" -lt 2 && NEWTAB=''
a0685a4f git-web--browse.sh (Dmitry Potapov   2008-02-09 23:22:22 -0800 160)    "$browser_path" $NEWTAB "$@" &

And you want to know the history of what is now line 155.

Then, use git log. Here, -L 155,155:git-web--browse.sh means "trace the evolution of lines 155 to 155 in the file named git-web--browse.sh".

$ git log --pretty=short -u -L 155,155:git-web--browse.sh
commit 81f42f11496b9117273939c98d270af273c8a463
Author: Giuseppe Bilotta <[email protected]>

    web--browse: support opera, seamonkey and elinks

diff --git a/git-web--browse.sh b/git-web--browse.sh
--- a/git-web--browse.sh
+++ b/git-web--browse.sh
@@ -143,1 +143,1 @@
-firefox|iceweasel)
+firefox|iceweasel|seamonkey|iceape)

commit a180055a47c6793eaaba6289f623cff32644215b
Author: Giuseppe Bilotta <[email protected]>

    web--browse: coding style

diff --git a/git-web--browse.sh b/git-web--browse.sh
--- a/git-web--browse.sh
+++ b/git-web--browse.sh
@@ -142,1 +142,1 @@
-    firefox|iceweasel)
+firefox|iceweasel)

commit 5884f1fe96b33d9666a78e660042b1e3e5f9f4d9
Author: Christian Couder <[email protected]>

    Rename 'git-help--browse.sh' to 'git-web--browse.sh'.

diff --git a/git-web--browse.sh b/git-web--browse.sh
--- /dev/null
+++ b/git-web--browse.sh
@@ -0,0 +127,1 @@
+    firefox|iceweasel)

You can get a set of commits by using pick-axe.

git log -S'the line from your file' -- path/to/your/file.txt

This will give you all of the commits that affected that text in that file. If the file was renamed at some point, you can add --follow-parent.

If you would like to inspect the commits at each of these edits, you can pipe that result to git show:

git log ... | xargs -n 1 git show