1GIT-BLAME(1) Git Manual GIT-BLAME(1)
2
6 git-blame - Show what revision and author last modified each line of a
7 file
8
10 git blame [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-e] [-p] [-w] [--incremental]
11 [-L <range>] [-S <revs-file>] [-M] [-C] [-C] [-C] [--since=<date>]
12 [--ignore-rev <rev>] [--ignore-revs-file <file>]
13 [--color-lines] [--color-by-age] [--progress] [--abbrev=<n>]
14 [ --contents <file> ] [<rev> | --reverse <rev>..<rev>] [--] <file>
15
17 Annotates each line in the given file with information from the
18 revision which last modified the line. Optionally, start annotating
19 from the given revision.
20 When specified one or more times, -L restricts annotation to the
22 requested lines.
23 The origin of lines is automatically followed across whole-file renames
25 (currently there is no option to turn the rename-following off). To
26 follow lines moved from one file to another, or to follow lines that
27 were copied and pasted from another file, etc., see the -C and -M
28 options.
29 The report does not tell you anything about lines which have been
31 deleted or replaced; you need to use a tool such as git diff or the
32 "pickaxe" interface briefly mentioned in the following paragraph.
33 Apart from supporting file annotation, Git also supports searching the
35 development history for when a code snippet occurred in a change. This
36 makes it possible to track when a code snippet was added to a file,
37 moved or copied between files, and eventually deleted or replaced. It
38 works by searching for a text string in the diff. A small example of
39 the pickaxe interface that searches for blame_usage:
40 $ git log --pretty=oneline -S'blame_usage'
42 5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S <ancestry-file>
43 ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output
44
46 -b
47 Show blank SHA-1 for boundary commits. This can also be controlled
48 via the blame.blankBoundary config option.
49 --root
51 Do not treat root commits as boundaries. This can also be
52 controlled via the blame.showRoot config option.
53 --show-stats
55 Include additional statistics at the end of blame output.
56 -L <start>,<end>, -L :<funcname>
58 Annotate only the line range given by <start>,<end>, or by the
59 function name regex <funcname>. May be specified multiple times.
60 Overlapping ranges are allowed.
61 <start> and <end> are optional. -L <start> or -L <start>, spans
63 from <start> to end of file. -L ,<end> spans from start of file to
64 <end>.
65 <start> and <end> can take one of these forms:
67 • number
69 If <start> or <end> is a number, it specifies an absolute line
71 number (lines count from 1).
72 • /regex/
74 This form will use the first line matching the given POSIX
76 regex. If <start> is a regex, it will search from the end of
77 the previous -L range, if any, otherwise from the start of
78 file. If <start> is ^/regex/, it will search from the start of
79 file. If <end> is a regex, it will search starting at the line
80 given by <start>.
81 • +offset or -offset
83 This is only valid for <end> and will specify a number of lines
85 before or after the line given by <start>.
86 If :<funcname> is given in place of <start> and <end>, it is a
88 regular expression that denotes the range from the first funcname
89 line that matches <funcname>, up to the next funcname line.
90 :<funcname> searches from the end of the previous -L range, if any,
91 otherwise from the start of file. ^:<funcname> searches from the
92 start of file. The function names are determined in the same way as
93 git diff works out patch hunk headers (see Defining a custom
94 hunk-header in gitattributes(5)).
95 -l
97 Show long rev (Default: off).
98 -t
100 Show raw timestamp (Default: off).
101 -S <revs-file>
103 Use revisions from revs-file instead of calling git-rev-list(1).
104 --reverse <rev>..<rev>
106 Walk history forward instead of backward. Instead of showing the
107 revision in which a line appeared, this shows the last revision in
108 which a line has existed. This requires a range of revision like
109 START..END where the path to blame exists in START. git blame
110 --reverse START is taken as git blame --reverse START..HEAD for
111 convenience.
112 --first-parent
114 Follow only the first parent commit upon seeing a merge commit.
115 This option can be used to determine when a line was introduced to
116 a particular integration branch, rather than when it was introduced
117 to the history overall.
118 -p, --porcelain
120 Show in a format designed for machine consumption.
121 --line-porcelain
123 Show the porcelain format, but output commit information for each
124 line, not just the first time a commit is referenced. Implies
125 --porcelain.
126 --incremental
128 Show the result incrementally in a format designed for machine
129 consumption.
130 --encoding=<encoding>
132 Specifies the encoding used to output author names and commit
133 summaries. Setting it to none makes blame output unconverted data.
134 For more information see the discussion about encoding in the git-
135 log(1) manual page.
136 --contents <file>
138 Annotate using the contents from the named file, starting from
139 <rev> if it is specified, and HEAD otherwise. You may specify - to
140 make the command read from the standard input for the file
141 contents.
142 --date <format>
144 Specifies the format used to output dates. If --date is not
145 provided, the value of the blame.date config variable is used. If
146 the blame.date config variable is also not set, the iso format is
147 used. For supported values, see the discussion of the --date option
148 at git-log(1).
149 --[no-]progress
151 Progress status is reported on the standard error stream by default
152 when it is attached to a terminal. This flag enables progress
153 reporting even if not attached to a terminal. Can’t use --progress
154 together with --porcelain or --incremental.
155 -M[<num>]
157 Detect moved or copied lines within a file. When a commit moves or
158 copies a block of lines (e.g. the original file has A and then B,
159 and the commit changes it to B and then A), the traditional blame
160 algorithm notices only half of the movement and typically blames
161 the lines that were moved up (i.e. B) to the parent and assigns
162 blame to the lines that were moved down (i.e. A) to the child
163 commit. With this option, both groups of lines are blamed on the
164 parent by running extra passes of inspection.
165 <num> is optional but it is the lower bound on the number of
167 alphanumeric characters that Git must detect as moving/copying
168 within a file for it to associate those lines with the parent
169 commit. The default value is 20.
170 -C[<num>]
172 In addition to -M, detect lines moved or copied from other files
173 that were modified in the same commit. This is useful when you
174 reorganize your program and move code around across files. When
175 this option is given twice, the command additionally looks for
176 copies from other files in the commit that creates the file. When
177 this option is given three times, the command additionally looks
178 for copies from other files in any commit.
179 <num> is optional but it is the lower bound on the number of
181 alphanumeric characters that Git must detect as moving/copying
182 between files for it to associate those lines with the parent
183 commit. And the default value is 40. If there are more than one -C
184 options given, the <num> argument of the last -C will take effect.
185 --ignore-rev <rev>
187 Ignore changes made by the revision when assigning blame, as if the
188 change never happened. Lines that were changed or added by an
189 ignored commit will be blamed on the previous commit that changed
190 that line or nearby lines. This option may be specified multiple
191 times to ignore more than one revision. If the
192 blame.markIgnoredLines config option is set, then lines that were
193 changed by an ignored commit and attributed to another commit will
194 be marked with a ? in the blame output. If the
195 blame.markUnblamableLines config option is set, then those lines
196 touched by an ignored commit that we could not attribute to another
197 revision are marked with a *.
198 --ignore-revs-file <file>
200 Ignore revisions listed in file, which must be in the same format
201 as an fsck.skipList. This option may be repeated, and these files
202 will be processed after any files specified with the
203 blame.ignoreRevsFile config option. An empty file name, "", will
204 clear the list of revs from previously processed files.
205 --color-lines
207 Color line annotations in the default format differently if they
208 come from the same commit as the preceding line. This makes it
209 easier to distinguish code blocks introduced by different commits.
210 The color defaults to cyan and can be adjusted using the
211 color.blame.repeatedLines config option.
212 --color-by-age
214 Color line annotations depending on the age of the line in the
215 default format. The color.blame.highlightRecent config option
216 controls what color is used for each range of age.
217 -h
219 Show help message.
220 -c
222 Use the same output mode as git-annotate(1) (Default: off).
223 --score-debug
225 Include debugging information related to the movement of lines
226 between files (see -C) and lines moved within a file (see -M). The
227 first number listed is the score. This is the number of
228 alphanumeric characters detected as having been moved between or
229 within files. This must be above a certain threshold for git blame
230 to consider those lines of code to have been moved.
231 -f, --show-name
233 Show the filename in the original commit. By default the filename
234 is shown if there is any line that came from a file with a
235 different name, due to rename detection.
236 -n, --show-number
238 Show the line number in the original commit (Default: off).
239 -s
241 Suppress the author name and timestamp from the output.
242 -e, --show-email
244 Show the author email instead of the author name (Default: off).
245 This can also be controlled via the blame.showEmail config option.
246 -w
248 Ignore whitespace when comparing the parent’s version and the
249 child’s to find where the lines came from.
250 --abbrev=<n>
252 Instead of using the default 7+1 hexadecimal digits as the
253 abbreviated object name, use <m>+1 digits, where <m> is at least
254 <n> but ensures the commit object names are unique. Note that 1
255 column is used for a caret to mark the boundary commit.
256
258 When neither --porcelain nor --incremental option is specified, git
259 blame will output annotation for each line with:
260 • abbreviated object name for the commit the line came from;
262 • author ident (by default the author name and date, unless -s or -e
264 is specified); and
265 • line number
267 before the line contents.
269
271 In this format, each line is output after a header; the header at the
272 minimum has the first line which has:
273 • 40-byte SHA-1 of the commit the line is attributed to;
275 • the line number of the line in the original file;
277 • the line number of the line in the final file;
279 • on a line that starts a group of lines from a different commit than
281 the previous one, the number of lines in this group. On subsequent
282 lines this field is absent.
283 This header line is followed by the following information at least once
285 for each commit:
286 • the author name ("author"), email ("author-mail"), time
288 ("author-time"), and time zone ("author-tz"); similarly for
289 committer.
290 • the filename in the commit that the line is attributed to.
292 • the first line of the commit log message ("summary").
294 The contents of the actual line are output after the above header,
296 prefixed by a TAB. This is to allow adding more header elements later.
297 The porcelain format generally suppresses commit information that has
299 already been seen. For example, two lines that are blamed to the same
300 commit will both be shown, but the details for that commit will be
301 shown only once. This is more efficient, but may require more state be
302 kept by the reader. The --line-porcelain option can be used to output
303 full commit information for each line, allowing simpler (but less
304 efficient) usage like:
305 # count the number of lines attributed to each author
307 git blame --line-porcelain file |
308 sed -n 's/^author //p' |
309 sort | uniq -c | sort -rn
310
312 Unlike git blame and git annotate in older versions of git, the extent
313 of the annotation can be limited to both line ranges and revision
314 ranges. The -L option, which limits annotation to a range of lines, may
315 be specified multiple times.
316 When you are interested in finding the origin for lines 40-60 for file
318 foo, you can use the -L option like so (they mean the same thing — both
319 ask for 21 lines starting at line 40):
320 git blame -L 40,60 foo
322 git blame -L 40,+21 foo
323 Also you can use a regular expression to specify the line range:
325 git blame -L '/^sub hello {/,/^}$/' foo
327 which limits the annotation to the body of the hello subroutine.
329 When you are not interested in changes older than version v2.6.18, or
331 changes older than 3 weeks, you can use revision range specifiers
332 similar to git rev-list:
333 git blame v2.6.18.. -- foo
335 git blame --since=3.weeks -- foo
336 When revision range specifiers are used to limit the annotation, lines
338 that have not changed since the range boundary (either the commit
339 v2.6.18 or the most recent commit that is more than 3 weeks old in the
340 above example) are blamed for that range boundary commit.
341 A particularly useful way is to see if an added file has lines created
343 by copy-and-paste from existing files. Sometimes this indicates that
344 the developer was being sloppy and did not refactor the code properly.
345 You can first find the commit that introduced the file with:
346 git log --diff-filter=A --pretty=short -- foo
348 and then annotate the change between the commit and its parents, using
350 commit^! notation:
351 git blame -C -C -f $commit^! -- foo
353
355 When called with --incremental option, the command outputs the result
356 as it is built. The output generally will talk about lines touched by
357 more recent commits first (i.e. the lines will be annotated out of
358 order) and is meant to be used by interactive viewers.
359 The output format is similar to the Porcelain format, but it does not
361 contain the actual lines from the file that is being annotated.
362 1. Each blame entry always starts with a line of:
364 <40-byte hex sha1> <sourceline> <resultline> <num_lines>
366 Line numbers count from 1.
368 2. The first time that a commit shows up in the stream, it has various
370 other information about it printed out with a one-word tag at the
371 beginning of each line describing the extra commit information
372 (author, email, committer, dates, summary, etc.).
373 3. Unlike the Porcelain format, the filename information is always
375 given and terminates the entry:
376 "filename" <whitespace-quoted-filename-goes-here>
378 and thus it is really quite easy to parse for some line- and
380 word-oriented parser (which should be quite natural for most
381 scripting languages).
382 Note
384 For people who do parsing: to make it more robust, just ignore
385 any lines between the first and last one ("<sha1>" and
386 "filename" lines) where you do not recognize the tag words (or
387 care about that particular one) at the beginning of the
388 "extended information" lines. That way, if there is ever added
389 information (like the commit encoding or extended commit
390 commentary), a blame viewer will not care.
391
393 See gitmailmap(5).
394
396 Everything below this line in this section is selectively included from
397 the git-config(1) documentation. The content is the same as what’s
398 found there:
399 blame.blankBoundary
401 Show blank commit object name for boundary commits in git-blame(1).
402 This option defaults to false.
403 blame.coloring
405 This determines the coloring scheme to be applied to blame output.
406 It can be repeatedLines, highlightRecent, or none which is the
407 default.
408 blame.date
410 Specifies the format used to output dates in git-blame(1). If unset
411 the iso format is used. For supported values, see the discussion of
412 the --date option at git-log(1).
413 blame.showEmail
415 Show the author email instead of author name in git-blame(1). This
416 option defaults to false.
417 blame.showRoot
419 Do not treat root commits as boundaries in git-blame(1). This
420 option defaults to false.
421 blame.ignoreRevsFile
423 Ignore revisions listed in the file, one unabbreviated object name
424 per line, in git-blame(1). Whitespace and comments beginning with #
425 are ignored. This option may be repeated multiple times. Empty file
426 names will reset the list of ignored revisions. This option will be
427 handled before the command line option --ignore-revs-file.
428 blame.markUnblamableLines
430 Mark lines that were changed by an ignored revision that we could
431 not attribute to another commit with a * in the output of git-
432 blame(1).
433 blame.markIgnoredLines
435 Mark lines that were changed by an ignored revision that we
436 attributed to another commit with a ? in the output of git-
437 blame(1).
438
440 git-annotate(1)
441
443 Part of the git(1) suite
444Git 2.43.0 11/20/2023 GIT-BLAME(1)