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--- git_blame [2018/05/21 09:47] – [Basic usage] rpjday
+++ git_blame [2019/03/07 14:04] (current) – [Some useful config options] rpjday
@@ Line 2: / Line 2: @@
 Most useful variations of ''git blame'', using examples from Linux kernel source.
+From ''man git-annotate'':
+<code>
+The only difference between this command and git-blame(1) is
+that they use slightly different output formats, and this
+command exists only for backward compatibility to support
+existing scripts, and provide a more familiar command name for
+people coming from other SCM systems.
+</code>
 ===== Basic usage =====
@@ Line 10: / Line 20: @@
 $ git blame Makefile
 b24413180f560 (Greg Kroah-Hartman       2017-11-01 15:07:57 +0100    1) # SPDX-License-Identifier: GPL-2.0
-c517d838eb7d0 (Linus Torvalds           2015-02-22 18:21:14 -0800    2) VERSION = 4
+bfeffd1552837 (Linus Torvalds           2019-01-06 17:08:20 -0800    2) VERSION = 5
-cc43fc88842 (Linus Torvalds           2018-04-15 18:24:20 -0700    3) PATCHLEVEL = 17
+bfeffd1552837 (Linus Torvalds           2019-01-06 17:08:20 -0800    3) PATCHLEVEL = 0
 c9d1b84b (Linus Torvalds           2011-05-29 17:43:36 -0700    4) SUBLEVEL = 0
-b8d5c708122 (Linus Torvalds           2018-05-13 16:15:17 -0700    5) EXTRAVERSION = -rc5
+d13937116f1e8 (Linus Torvalds           2019-02-10 14:42:20 -0800    5) EXTRAVERSION = -rc6
-bc37fefc447 (Linus Torvalds           2018-05-06 16:57:38 -1000    6) NAME = Merciless Moray
+e6e902d18502 (Linus Torvalds           2018-11-25 14:19:31 -0800    6) NAME = Shy Crocodile
 ^1da177e4c3f4 (Linus Torvalds           2005-04-16 15:20:36 -0700    7)
 ^1da177e4c3f4 (Linus Torvalds           2005-04-16 15:20:36 -0700    8) # *DOCUMENTATION*
@@ Line 21: / Line 31: @@
 ^1da177e4c3f4 (Linus Torvalds           2005-04-16 15:20:36 -0700   11) # Comments in this file are targeted only to the developer, do not
 ^1da177e4c3f4 (Linus Torvalds           2005-04-16 15:20:36 -0700   12) # expect to learn how to build the kernel reading this file.
 ^1da177e4c3f4 (Linus Torvalds           2005-04-16 15:20:36 -0700   13)
 ... snip ...
+</code>
+You can also use ''-L'' for //line limiting//:
+<code>
+$ git blame -L 1420,1430 Makefile
+db3e260bc8 (Vinícius Tinti   2017-04-24 13:04:58 -0700 1420)         @echo  '                    (requires compiler support for LLVM assembly generation)'
+6271897978072 (Joe Perches      2010-01-13 09:31:44 -0800 1421)         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
+6271897978072 (Joe Perches      2010-01-13 09:31:44 -0800 1422)         @echo  '                    (requires a recent binutils and recent build (System.map))'
+ad605b3c9c (Sam Ravnborg     2005-07-07 17:56:08 -0700 1423)         @echo  '  dir/file.ko     - Build module including final link'
+   (oh, look ...)
+c4d5ee67ce265 (Robert P. J. Day 2009-04-24 12:35:23 -0400 1424)         @echo  '  modules_prepare - Set up for building external modules'
+^1da177e4c3f4 (Linus Torvalds   2005-04-16 15:20:36 -0700 1425)         @echo  '  tags/TAGS       - Generate tags file for editors'
+^1da177e4c3f4 (Linus Torvalds   2005-04-16 15:20:36 -0700 1426)         @echo  '  cscope          - Generate cscope index'
+f4ed1009fcea8 (Jianbin Kang     2011-01-14 20:07:05 +0800 1427)         @echo  '  gtags           - Generate GNU GLOBAL index'
+f1d9a6cec011 (Michal Marek     2014-07-11 15:57:24 +0200 1428)         @echo  '  kernelrelease   - Output the release version string (use with make -s)'
+f1d9a6cec011 (Michal Marek     2014-07-11 15:57:24 +0200 1429)         @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
+f1d9a6cec011 (Michal Marek     2014-07-11 15:57:24 +0200 1430)         @echo  '  image_name      - Output the image name (use with make -s)'
+$
+</code>
+Once you determine the offending line, you can examine its encompassing commit with ''git show'':
+<code>
+$ git show c4d5ee67ce265
+commit c4d5ee67ce26503d7eaf2aca5bb13c58e89d1be8
+Author: Robert P. J. Day <rpjday@crashcourse.ca>
+Date:   Fri Apr 24 12:35:23 2009 -0400
+    kbuild: "make prepare" should be "make modules_prepare"
+    Correct the Makefile help text to read "make modules_prepare".
+    Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
+    Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
+diff --git a/Makefile b/Makefile
+index b309fca4b944..b18afad2e100 100644
+--- a/Makefile
++++ b/Makefile
+@@ -1293,7 +1293,7 @@ help:
+        @echo  '  dir/            - Build all files in dir and below'
+        @echo  '  dir/file.[ois]  - Build specified target only'
+        @echo  '  dir/file.ko     - Build module including final link'
+-       @echo  '  prepare         - Set up for building external modules'
++       @echo  '  modules_prepare - Set up for building external modules'
+        @echo  '  tags/TAGS       - Generate tags file for editors'
+        @echo  '  cscope          - Generate cscope index'
+        @echo  '  kernelrelease   - Output the release version string'
+</code>
+===== Some useful command-line options =====
+A //very// small subset of options for ''git blame'' (there are far more):
+<code>
+-L <start>,<end>, -L :<funcname>
+    Annotate only the given line range. May be specified multiple times.
+    Overlapping ranges are allowed.
+-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.
+</code>
+===== Some useful config options =====
+From ''man git-config'':
+<code>
+blame.blankBoundary
+    Show blank commit object name for boundary commits in git-
+    blame(1). This option defaults to false.
+blame.coloring
+    This determines the coloring scheme to be applied to blame
+    output. It can be repeatedLines, highlightRecent, or none
+    which is the default.
+blame.date
+    Specifies the format used to output dates in git-blame(1).
+    If unset the iso format is used. For supported values, see
+    the discussion of the --date option at git-log(1).
+blame.showEmail
+    Show the author email instead of author name in git-
+    blame(1). This option defaults to false.
+    blame.showRoot
+    Do not treat root commits as boundaries in git-blame(1).
+    This option defaults to false.
 </code>