X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=Documentation%2Fgit-blame.txt;h=bdfc6669285dc895a69fc0037246810bfa979de5;hb=490e092defd01ff645457cde4e96bc0d0d534ccd;hp=0a1fa00db0ab7ee39a551689cb50ffc602b53d41;hpb=abda1ef590d94a5e15e7ce3b685b5c092a790cfa;p=git.git diff --git a/Documentation/git-blame.txt b/Documentation/git-blame.txt index 0a1fa00db..bdfc66692 100644 --- a/Documentation/git-blame.txt +++ b/Documentation/git-blame.txt @@ -3,39 +3,165 @@ git-blame(1) NAME ---- -git-blame - Blame file lines on commits +git-blame - Show what revision and author last modified each line of a file SYNOPSIS -------- -git-blame file [options] file [revision] +[verse] +'git-blame' [-c] [-l] [-t] [-f] [-n] [-p] [-L n,m] [-S ] + [-M] [-C] [-C] [--since=] [] [--] DESCRIPTION ----------- -Annotates each line in the given file with information from the commit -which introduced the line. Start annotation from the given revision. + +Annotates each line in the given file with information from the revision which +last modified the line. Optionally, start annotating from the given revision. + +Also it can limit the range of lines annotated. + +This report doesn't tell you anything about lines which have been deleted or +replaced; you need to use a tool such as gitlink:git-diff[1] or the "pickaxe" +interface briefly mentioned in the following paragraph. + +Apart from supporting file annotation, git also supports searching the +development history for when a code snippet occured in a change. This makes it +possible to track when a code snippet was added to a file, moved or copied +between files, and eventually deleted or replaced. It works by searching for +a text string in the diff. A small example: + +----------------------------------------------------------------------------- +$ git log --pretty=oneline -S'blame_usage' +5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S +ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output +----------------------------------------------------------------------------- OPTIONS ------- -c, --compatibility:: - Use the same output mode as git-annotate (Default: off). + Use the same output mode as gitlink:git-annotate[1] (Default: off). + +-L n,m:: + Annotate only the specified line range (lines count from 1). -l, --long:: - Show long rev (Defaults off). + Show long rev (Default: off). + +-t, --time:: + Show raw timestamp (Default: off). -S, --rev-file :: - Use revs from revs-file instead of calling git-rev-list. + Use revs from revs-file instead of calling gitlink:git-rev-list[1]. + +-f, --show-name:: + Show filename in the original commit. By default + filename is shown if there is any line that came from a + file with different name, due to rename detection. + +-n, --show-number:: + Show line number in the original commit (Default: off). + +-p, --porcelain:: + Show in a format designed for machine consumption. + +-M:: + Detect moving lines in the file as well. When a commit + moves a block of lines in a file (e.g. the original file + has A and then B, and the commit changes it to B and + then A), traditional 'blame' algorithm typically blames + the lines that were moved up (i.e. B) to the parent and + assigns blame to the lines that were moved down (i.e. A) + to the child commit. With this option, both groups of + lines are blamed on the parent. + +-C:: + In addition to `-M`, detect lines copied from other + files that were modified in the same commit. This is + useful when you reorganize your program and move code + around across files. When this option is given twice, + the command looks for copies from all other files in the + parent for the commit that creates the file in addition. -h, --help:: Show help message. +THE PORCELAIN FORMAT +-------------------- + +In this format, each line is output after a header; the +header at the minumum has the first line which has: + +- 40-byte SHA-1 of the commit the line is attributed to; +- the line number of the line in the original file; +- the line number of the line in the final file; +- on a line that starts a group of line from a different + commit than the previous one, the number of lines in this + group. On subsequent lines this field is absent. + +This header line is followed by the following information +at least once for each commit: + +- author name ("author"), email ("author-mail"), time + ("author-time"), and timezone ("author-tz"); similarly + for committer. +- filename in the commit the line is attributed to. +- the first line of the commit log message ("summary"). + +The contents of the actual line is output after the above +header, prefixed by a TAB. This is to allow adding more +header elements later. + + +SPECIFIYING RANGES +------------------ + +Unlike `git-blame` and `git-annotate` in older git, the extent +of annotation can be limited to both line ranges and revision +ranges. When you are interested in finding the origin for +ll. 40-60 for file `foo`, you can use `-L` option like this: + + git blame -L 40,60 foo + +Also you can use regular expression to specify the line range. + + git blame -L '/^sub hello {/,/^}$/' foo + +would limit the annotation to the body of `hello` subroutine. + +When you are not interested in changes older than the version +v2.6.18, or changes older than 3 weeks, you can use revision +range specifiers similar to `git-rev-list`: + + git blame v2.6.18.. -- foo + git blame --since=3.weeks -- foo + +When revision range specifiers are used to limit the annotation, +lines that have not changed since the range boundary (either the +commit v2.6.18 or the most recent commit that is more than 3 +weeks old in the above example) are blamed for that range +boundary commit. + +A particularly useful way is to see if an added file have lines +created by copy-and-paste from existing files. Sometimes this +indicates that the developer was being sloppy and did not +refactor the code properly. You can first find the commit that +introduced the file with: + + git log --diff-filter=A --pretty=short -- foo + +and then annotate the change between the commit and its +parents, using `commit{caret}!` notation: + + git blame -C -C -f $commit^! -- foo + + SEE ALSO -------- gitlink:git-annotate[1] AUTHOR ------ -Written by Fredrik Kuivinen . +Written by Junio C Hamano GIT ---