From: david@lang.hm Date: Fri, 02 Jan 2009 23:56:05 GMT Subject: Re: how to track the history of a line in a file Message-ID: In-Reply-To: On Fri, 2 Jan 2009, david@lang.hm wrote: > On Fri, 2 Jan 2009, david@lang.hm wrote: > >> On Fri, 2 Jan 2009, Jeff King wrote: >> >>> The tricky thing here is what is "this line"? Using the line number >>> isn't right, since it will change based on other content coming in and >>> out of the file. You can keep drilling down by reblaming parent commits, >>> but remember that each time you do that you are manually looking at the >>> content and saying "Oh, this is the line I am still interested in." So I >>> a script would have to correlate the old version and new version of the >>> line and realize how to follow the "interesting" thing. >>> >>> In your case, I think you want to see any commit in Makefile which >>> changed a line with SUBLEVEL in it. Which is maybe easiest done as: >>> >>> git log -z -p Makefile | >>> perl -0ne 'print if /\n[+-]SUBLEVEL/' | >>> tr '\0' '\n' >>> >>> and is pretty fast. But obviously we're leveraging some content-specific >>> knowledge about what's in the Makefile. >> >> Ok, I hacked togeather a quick bash script to try this >> > >> the problem that this has is that line 3 of $COMMIT may not be line 3 of >> $COMMIT^, and if they aren't it ends up hunting down the wrong data >> >> either that or I am not understanding the output of git blame properly >> (also very possible) > > I was misunderstanding git blame > > new script is > > #!/bin/bash > line=`git blame -n -b -l -L /$1/,+1 -M $2` > echo "-$line" > foundCOMMIT=`echo "$line" |cut -c -40` > foundline=`echo "$line" |cut -c 42- |cut -f 1 -d " "` > while [ "$foundCOMMIT" != " " ] ;do > #git diff -U0 $foundCOMMIT..$foundCOMMIT^ $2 > line=`git blame -n -b -l -L $foundline,+1 -M $2 $foundCOMMIT^` > echo "-$line" > foundCOMMIT=`echo "$line" |cut -c -40` > foundline=`echo "$line" |cut -c 42- |cut -f 1 -d " "` > done > > this seems to be working for me now. not quite, it works as long as the line doesn't move in the commit where it changes. David Lang