git-blame (1)
Quick Reference
Show commit hash and last author on each line of a file.
- Print file with author name and commit hash on each line:
git blame {{file}}
- Print file with author email and commit hash on each line:
git blame -e {{file}}
NAME
git-blame - Show what revision and author last modified each line of a fileSYNOPSIS
git blame [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-e] [-p] [-w] [--incremental] [-L <range>] [-S <revs-file>] [-M] [-C] [-C] [-C] [--since=<date>] [--progress] [--abbrev=<n>] [<rev> | --contents <file> | --reverse <rev>..<rev>] [--] <file>
DESCRIPTION
Annotates each line in the given file with information from the revision which last modified the line. Optionally, start annotating from the given revision.$ git log --pretty=oneline -S'blame_usage' 5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S <ancestry-file> ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output
OPTIONS
-bShow blank SHA-1 for boundary commits. This can also be controlled via the blame.blankboundary config option.
--root
Do not treat root commits as boundaries. This can also be controlled via the blame.showRoot config option.
--show-stats
Include additional statistics at the end of blame output.
-L <start>,<end>, -L :<funcname>
Annotate only the given line range. May be specified multiple times. Overlapping ranges are allowed.
<start> and <end> are optional. “-L <start>” or “-L <start>,” spans from <start> to end of file. “-L ,<end>” spans from start of file to <end>.
<start> and <end> can take one of these forms:
If “:<funcname>” is given in place of <start> and <end>, it is a regular expression that denotes the range from the first funcname line that matches <funcname>, up to the next funcname line. “:<funcname>” searches from the end of the previous -L range, if any, otherwise from the start of file. “^:<funcname>” searches from the start of file.
-l
•number
If <start> or <end> is a number, it specifies an absolute line number (lines count from 1).
•/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>.
•+offset or -offset
This is only valid for <end> and will specify a number of lines before or after the line given by <start>.
Show long rev (Default: off).
-t
Show raw timestamp (Default: off).
-S <revs-file>
Use revisions from revs-file instead of calling git-rev-list(1).
--reverse <rev>..<rev>
Walk history forward instead of backward. Instead of showing the revision in which a line appeared, this shows the last revision in which a line has existed. This requires a range of revision like START..END where the path to blame exists in START. git blame --reverse START is taken as git blame --reverse START..HEAD for convenience.
-p, --porcelain
Show in a format designed for machine consumption.
--line-porcelain
Show the porcelain format, but output commit information for each line, not just the first time a commit is referenced. Implies --porcelain.
--incremental
Show the result incrementally in a format designed for machine consumption.
--encoding=<encoding>
Specifies the encoding used to output author names and commit summaries. Setting it to none makes blame output unconverted data. For more information see the discussion about encoding in the git-log(1) manual page.
--contents <file>
When <rev> is not specified, the command annotates the changes starting backwards from the working tree copy. This flag makes the command pretend as if the working tree copy has the contents of the named file (specify - to make the command read from the standard input).
--date <format>
Specifies the format used to output dates. If --date is not provided, the value of the blame.date config variable is used. If the blame.date config variable is also not set, the iso format is used. For supported values, see the discussion of the --date option at git-log(1).
--[no-]progress
Progress status is reported on the standard error stream by default when it is attached to a terminal. This flag enables progress reporting even if not attached to a terminal. Can’t use --progress together with --porcelain or --incremental.
-M[<num>]
Detect moved or copied lines within a file. When a commit moves or copies a block of lines (e.g. the original file has A and then B, and the commit changes it to B and then A), the traditional blame algorithm notices only half of the movement and 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 by running extra passes of inspection.
<num> is optional but it is the lower bound on the number of alphanumeric characters that Git must detect as moving/copying within a file for it to associate those lines with the parent commit. The default value is 20.
-C[<num>]
In addition to -M, detect lines moved or 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 additionally looks for copies from other files in the commit that creates the file. When this option is given three times, the command additionally looks for copies from other files in any commit.
<num> is optional but it is the lower bound on the number of alphanumeric characters that Git must detect as moving/copying between files for it to associate those lines with the parent commit. And the default value is 40. If there are more than one -C options given, the <num> argument of the last -C will take effect.
-h
Show help message.
-c
Use the same output mode as git-annotate(1) (Default: off).
--score-debug
Include debugging information related to the movement of lines between files (see -C) and lines moved within a file (see -M). The first number listed is the score. This is the number of alphanumeric characters detected as having been moved between or within files. This must be above a certain threshold for git blame to consider those lines of code to have been moved.
-f, --show-name
Show the filename in the original commit. By default the filename is shown if there is any line that came from a file with a different name, due to rename detection.
-n, --show-number
Show the line number in the original commit (Default: off).
-s
Suppress the author name and timestamp from the output.
-e, --show-email
Show the author email instead of author name (Default: off). This can also be controlled via the blame.showEmail config option.
-w
Ignore whitespace when comparing the parent’s version and the child’s to find where the lines came from.
--abbrev=<n>
Instead of using the default 7+1 hexadecimal digits as the abbreviated object name, use <n>+1 digits. Note that 1 column is used for a caret to mark the boundary commit.
THE PORCELAIN FORMAT
In this format, each line is output after a header; the header at the minimum 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 lines from a different commit than the previous one, the number of lines in this group. On subsequent lines this field is absent.
•the author name ("author"), email ("author-mail"), time ("author-time"), and time zone ("author-tz"); similarly for committer.
•the filename in the commit that the line is attributed to.
•the first line of the commit log message ("summary").
# count the number of lines attributed to each author git blame --line-porcelain file | sed -n 's/^author //p' | sort | uniq -c | sort -rn
SPECIFYING RANGES
Unlike git blame and git annotate in older versions of git, the extent of the annotation can be limited to both line ranges and revision ranges. The -L option, which limits annotation to a range of lines, may be specified multiple times.git blame -L 40,60 foo git blame -L 40,+21 foo
git blame -L '/^sub hello {/,/^}$/' foo
git blame v2.6.18.. -- foo git blame --since=3.weeks -- foo
git log --diff-filter=A --pretty=short -- foo
git blame -C -C -f $commit^! -- foo
INCREMENTAL OUTPUT
When called with --incremental option, the command outputs the result as it is built. The output generally will talk about lines touched by more recent commits first (i.e. the lines will be annotated out of order) and is meant to be used by interactive viewers. 1.Each blame entry always starts with a line of:
Line numbers count from 1.
<40-byte hex sha1> <sourceline> <resultline> <num_lines>
2.The first time that a commit shows up in the stream, it has various other information about it printed out with a one-word tag at the beginning of each line describing the extra commit information (author, email, committer, dates, summary, etc.).
3.Unlike the Porcelain format, the filename information is always given and terminates the entry:
and thus it is really quite easy to parse for some line- and word-oriented parser (which should be quite natural for most scripting languages).
Note
For people who do parsing: to make it more robust, just ignore any lines between the first and last one ("<sha1>" and "filename" lines) where you do not recognize the tag words (or care about that particular one) at the beginning of the "extended information" lines. That way, if there is ever added information (like the commit encoding or extended commit commentary), a blame viewer will not care.
"filename" <whitespace-quoted-filename-goes-here>
MAPPING AUTHORS
If the file .mailmap exists at the toplevel of the repository, or at the location pointed to by the mailmap.file or mailmap.blob configuration options, it is used to map author and committer names and email addresses to canonical real names and email addresses.Proper Name <commit@email.xx>
<proper@email.xx> <commit@email.xx>
Proper Name <proper@email.xx> <commit@email.xx>
Proper Name <proper@email.xx> Commit Name <commit@email.xx>
Joe Developer <joe@example.com> Joe R. Developer <joe@example.com> Jane Doe <jane@example.com> Jane Doe <jane@laptop.(none)> Jane D. <jane@desktop.(none)>
Jane Doe <jane@desktop.(none)> Joe R. Developer <joe@example.com>
nick1 <bugs@company.xx> nick2 <bugs@company.xx> nick2 <nick2@company.xx> santa <me@company.xx> claus <me@company.xx> CTO <cto@coompany.xx>
<cto@company.xx> <cto@coompany.xx> Some Dude <some@dude.xx> nick1 <bugs@company.xx> Other Author <other@author.xx> nick2 <bugs@company.xx> Other Author <other@author.xx> <nick2@company.xx> Santa Claus <santa.claus@northpole.xx> <me@company.xx>