History of changes to a particular line of code in Subversion

Question

Is it possible to see the history of changes to a particular line of code in a Subversion repository?

I\'d like, for instance, to be able to see when a particular st

Answer 1

In the TortoiseSVN client there is a very nice feature that lets you:

• blame a file, displaying the last change for each line (this is standard)
• "blame previous revision", after clicking on a particular line in the above view (this is the good one)

The second feature does what it says - it shows the annotated revision preceding the last modification to the line. By using this feature iteratively, you can trace back through the history of a particular line.

Answer 2

A start is the command svn blame (or annotate,praise). It will show you when a line of code was last modified and by whom it was modified. e.g.:

  4564    wiemann # $Id$
  4564    wiemann # Author: David Goodger <goodger@python.org>
   778    goodger # Copyright: This module has been placed in the public domain.
   217    goodger 

Answer 3

The key here is how much history is required. As others have pointed out, the short answer is: svn blame (see svn help blame for details). If you're reaching far back in history or dealing with significant changes, you will likely need more than just this one command.

I just had to do this myself, and found this (ye ole) thread here on SO. Here's what I did to solve it with just the CLI, specifically for my case where an API had changed (e.g. while porting someone's far outdated work (not on a branch, arrgh!) back into a feature branch based off of an up-to-date trunk). E.g. function names had changed enough to where it wasn't apparent which function needed to be called.

Step One

The following command allowed me to page through commits where things had changed in the file "fileName.h" and to see the corresponding revision number (note: you may have to alter the '10' for more or less context per your svn log text).

svn log | grep -C 10 "fileName.h" | less

This results in a list of revisions in which this file was modified.

Step Two

Then it was a simple matter of using blame (or as others have pointed out, annotate) to narrow down to the revisions of interest.

cd trunk
svn blame fileName.h@r35948 | less

E.g. found the revision of interest was 35948.

Step Three

Having found the revision(s) of interest via blame, a diff can be produced to leverage the SVN tool.

svn diff -r35948:PREV fileName.h

Conclusion

Having a visual diff made it much easier to identify the old API names with the newer/updated API names.

Answer 4

I'd usually:

1. Run svn blame FILE first.
2. Note the last revision of the particular line.

3. Do another query with the -r argument:

   svn blame FILE -r 1:REV
   

4. Trace manually from there.

Answer 5

If you use Emacs, the built-in package vc can do this.

1. Navigate to the file in question.
2. Run the command vc-annotate with either M-x vc-annotate or C-xvg.
3. Each line will show up with its revision, like a normal svn blame.
4. Pressing a (vc-annotate-revision-previous-to-line) will navigate to the revision before the revision at the line you're on.

Answer 6

svn annotate

The AKA SVN Blame from TortoiseSVN.