see history of region in git

Question

I wonder is there any way to see the history of a region in git, ie all the commits that touched some pieces of code (defined as several contiguous lines of code)? I think this is kind of cool.

I am using magit, so any suggestions on how to use magit to achieve this goal would be even better.

Answer 1

A first simple solution is git log -- file1 file2 dir1 : it will only show the commit which touched those files / directories.

Another approach would be using git gui blame <commit> file Here each line of file will be annotated with the sha1 which introduced it, and you can click those sha1 to navigate among commits.

Answer 2

You probably want git-log -L

 -L <start>,<end>:<file>, -L :<regex>:<file>
     Trace the evolution of the line range given by "<start>,<end>" (or the
     funcname regex <regex>) within the <file>. You may not give any pathspec
     limiters. This is currently limited to a walk starting from a single revision,
     i.e., you may only give zero or one positive revision arguments. You can
     specify this option more than once.

     <start> and <end> can take one of these forms:

     o   number

         If <start> or <end> is a number, it specifies an absolute line number
         (lines count from 1).

     o   /regex/

         This form will use the first line matching the given POSIX regex. If
         <start> is a regex, it will search from the end of the previous -L range,
         if any, otherwise from the start of file. If <start> is "^/regex/", it
         will search from the start of file. If <end> is a regex, it will search
         starting at the line given by <start>.

     o   +offset or -offset

         This is only valid for <end> and will specify a number of lines before or
         after the line given by <start>.

     If '`:<regex>'' is given in place of <start> and <end>, it denotes the range
     from the first funcname line that matches <regex>, up to the next funcname
     line. `:<regex>'' searches from the end of the previous `-L range, if any,
     otherwise from the start of file. "^:<regex>" searches from the start of file.

For magit specifically, there's no current support, but there is an relevant open issue: https://github.com/magit/magit/issues/1717