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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
commitc8bae7493d2f2910b57f13ded012e86bdcfb0532 (patch)
tree24e09d9f84dec336720cf393e156089ca2835791 /Documentation/git-blame.txt
parentInitial commit. (diff)
downloadgit-c8bae7493d2f2910b57f13ded012e86bdcfb0532.tar.xz
git-c8bae7493d2f2910b57f13ded012e86bdcfb0532.zip
Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+git-blame(1)
+============
+
+NAME
+----
+git-blame - Show what revision and author last modified each line of a file
+
+SYNOPSIS
+--------
+[verse]
+'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>]
+ [--ignore-rev <rev>] [--ignore-revs-file <file>]
+ [--color-lines] [--color-by-age] [--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.
+
+When specified one or more times, `-L` restricts annotation to the requested
+lines.
+
+The origin of lines is automatically followed across whole-file
+renames (currently there is no option to turn the rename-following
+off). To follow lines moved from one file to another, or to follow
+lines that were copied and pasted from another file, etc., see the
+`-C` and `-M` options.
+
+The report does not tell you anything about lines which have been deleted or
+replaced; you need to use a tool such as 'git diff' 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 occurred 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 of the pickaxe interface
+that searches for `blame_usage`:
+
+-----------------------------------------------------------------------------
+$ git log --pretty=oneline -S'blame_usage'
+5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S <ancestry-file>
+ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output
+-----------------------------------------------------------------------------
+
+OPTIONS
+-------
+include::blame-options.txt[]
+
+-c::
+ Use the same output mode as linkgit: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 <m>+1 digits, where <m> is at
+ least <n> but ensures the commit object names are unique.
+ Note that 1 column
+ is used for a caret to mark the boundary commit.
+
+
+THE DEFAULT FORMAT
+------------------
+
+When neither `--porcelain` nor `--incremental` option is specified,
+`git blame` will output annotation for each line with:
+
+- abbreviated object name for the commit the line came from;
+- author ident (by default author name and date, unless `-s` or `-e`
+ is specified); and
+- line number
+
+before the line contents.
+
+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.
+
+This header line is followed by the following information
+at least once for each commit:
+
+- 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").
+
+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.
+
+The porcelain format generally suppresses commit information that has
+already been seen. For example, two lines that are blamed to the same
+commit will both be shown, but the details for that commit will be shown
+only once. This is more efficient, but may require more state be kept by
+the reader. The `--line-porcelain` option can be used to output full
+commit information for each line, allowing simpler (but less efficient)
+usage like:
+
+ # 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.
+
+When you are interested in finding the origin for
+lines 40-60 for file `foo`, you can use the `-L` option like so
+(they mean the same thing -- both ask for 21 lines starting at
+line 40):
+
+ git blame -L 40,60 foo
+ git blame -L 40,+21 foo
+
+Also you can use a regular expression to specify the line range:
+
+ git blame -L '/^sub hello {/,/^}$/' foo
+
+which limits the annotation to the body of the `hello` subroutine.
+
+When you are not interested in changes older than 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 has 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^!` notation:
+
+ 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.
+
+The output format is similar to the Porcelain format, but it
+does not contain the actual lines from the file that is being
+annotated.
+
+. Each blame entry always starts with a line of:
+
+ <40-byte hex sha1> <sourceline> <resultline> <num_lines>
++
+Line numbers count from 1.
+
+. 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.).
+
+. Unlike the Porcelain format, the filename information is always
+ given and terminates the entry:
+
+ "filename" <whitespace-quoted-filename-goes-here>
++
+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.
+
+
+MAPPING AUTHORS
+---------------
+
+See linkgit:gitmailmap[5].
+
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/blame.txt[]
+
+SEE ALSO
+--------
+linkgit:git-annotate[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite