6 git-blame - Show what revision and author last modified each line of a file
11 'git blame' [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-e] [-p] [-w] [--incremental]
12 [-L <range>] [-S <revs-file>] [-M] [-C] [-C] [-C] [--since=<date>]
13 [--abbrev=<n>] [<rev> | --contents <file> | --reverse <rev>] [--] <file>
18 Annotates each line in the given file with information from the revision which
19 last modified the line. Optionally, start annotating from the given revision.
21 When specified one or more times, `-L` restricts annotation to the requested
24 The origin of lines is automatically followed across whole-file
25 renames (currently there is no option to turn the rename-following
26 off). To follow lines moved from one file to another, or to follow
27 lines that were copied and pasted from another file, etc., see the
28 `-C` and `-M` options.
30 The report does not tell you anything about lines which have been deleted or
31 replaced; you need to use a tool such as 'git diff' or the "pickaxe"
32 interface briefly mentioned in the following paragraph.
34 Apart from supporting file annotation, Git also supports searching the
35 development history for when a code snippet occurred in a change. This makes it
36 possible to track when a code snippet was added to a file, moved or copied
37 between files, and eventually deleted or replaced. It works by searching for
38 a text string in the diff. A small example of the pickaxe interface
39 that searches for `blame_usage`:
41 -----------------------------------------------------------------------------
42 $ git log --pretty=oneline -S'blame_usage'
43 5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S <ancestry-file>
44 ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output
45 -----------------------------------------------------------------------------
49 include::blame-options.txt[]
52 Use the same output mode as linkgit:git-annotate[1] (Default: off).
55 Include debugging information related to the movement of
56 lines between files (see `-C`) and lines moved within a
57 file (see `-M`). The first number listed is the score.
58 This is the number of alphanumeric characters detected
59 as having been moved between or within files. This must be above
60 a certain threshold for 'git blame' to consider those lines
61 of code to have been moved.
65 Show the filename in the original commit. By default
66 the filename is shown if there is any line that came from a
67 file with a different name, due to rename detection.
71 Show the line number in the original commit (Default: off).
74 Suppress the author name and timestamp from the output.
78 Show the author email instead of author name (Default: off).
79 This can also be controlled via the `blame.showEmail` config
83 Ignore whitespace when comparing the parent's version and
84 the child's to find where the lines came from.
87 Instead of using the default 7+1 hexadecimal digits as the
88 abbreviated object name, use <n>+1 digits. Note that 1 column
89 is used for a caret to mark the boundary commit.
95 In this format, each line is output after a header; the
96 header at the minimum has the first line which has:
98 - 40-byte SHA-1 of the commit the line is attributed to;
99 - the line number of the line in the original file;
100 - the line number of the line in the final file;
101 - on a line that starts a group of lines from a different
102 commit than the previous one, the number of lines in this
103 group. On subsequent lines this field is absent.
105 This header line is followed by the following information
106 at least once for each commit:
108 - the author name ("author"), email ("author-mail"), time
109 ("author-time"), and time zone ("author-tz"); similarly
111 - the filename in the commit that the line is attributed to.
112 - the first line of the commit log message ("summary").
114 The contents of the actual line is output after the above
115 header, prefixed by a TAB. This is to allow adding more
116 header elements later.
118 The porcelain format generally suppresses commit information that has
119 already been seen. For example, two lines that are blamed to the same
120 commit will both be shown, but the details for that commit will be shown
121 only once. This is more efficient, but may require more state be kept by
122 the reader. The `--line-porcelain` option can be used to output full
123 commit information for each line, allowing simpler (but less efficient)
126 # count the number of lines attributed to each author
127 git blame --line-porcelain file |
128 sed -n 's/^author //p' |
129 sort | uniq -c | sort -rn
135 Unlike 'git blame' and 'git annotate' in older versions of git, the extent
136 of the annotation can be limited to both line ranges and revision
137 ranges. The `-L` option, which limits annotation to a range of lines, may be
138 specified multiple times.
140 When you are interested in finding the origin for
141 lines 40-60 for file `foo`, you can use the `-L` option like so
142 (they mean the same thing -- both ask for 21 lines starting at
145 git blame -L 40,60 foo
146 git blame -L 40,+21 foo
148 Also you can use a regular expression to specify the line range:
150 git blame -L '/^sub hello {/,/^}$/' foo
152 which limits the annotation to the body of the `hello` subroutine.
154 When you are not interested in changes older than version
155 v2.6.18, or changes older than 3 weeks, you can use revision
156 range specifiers similar to 'git rev-list':
158 git blame v2.6.18.. -- foo
159 git blame --since=3.weeks -- foo
161 When revision range specifiers are used to limit the annotation,
162 lines that have not changed since the range boundary (either the
163 commit v2.6.18 or the most recent commit that is more than 3
164 weeks old in the above example) are blamed for that range
167 A particularly useful way is to see if an added file has lines
168 created by copy-and-paste from existing files. Sometimes this
169 indicates that the developer was being sloppy and did not
170 refactor the code properly. You can first find the commit that
171 introduced the file with:
173 git log --diff-filter=A --pretty=short -- foo
175 and then annotate the change between the commit and its
176 parents, using `commit^!` notation:
178 git blame -C -C -f $commit^! -- foo
184 When called with `--incremental` option, the command outputs the
185 result as it is built. The output generally will talk about
186 lines touched by more recent commits first (i.e. the lines will
187 be annotated out of order) and is meant to be used by
190 The output format is similar to the Porcelain format, but it
191 does not contain the actual lines from the file that is being
194 . Each blame entry always starts with a line of:
196 <40-byte hex sha1> <sourceline> <resultline> <num_lines>
198 Line numbers count from 1.
200 . The first time that a commit shows up in the stream, it has various
201 other information about it printed out with a one-word tag at the
202 beginning of each line describing the extra commit information (author,
203 email, committer, dates, summary, etc.).
205 . Unlike the Porcelain format, the filename information is always
206 given and terminates the entry:
208 "filename" <whitespace-quoted-filename-goes-here>
210 and thus it is really quite easy to parse for some line- and word-oriented
211 parser (which should be quite natural for most scripting languages).
214 For people who do parsing: to make it more robust, just ignore any
215 lines between the first and last one ("<sha1>" and "filename" lines)
216 where you do not recognize the tag words (or care about that particular
217 one) at the beginning of the "extended information" lines. That way, if
218 there is ever added information (like the commit encoding or extended
219 commit commentary), a blame viewer will not care.
225 include::mailmap.txt[]
230 linkgit:git-annotate[1]
234 Part of the linkgit:git[1] suite