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GIT-FORMAT-PATCH(1)                                   Git Manual                                  GIT-FORMAT-PATCH(1)



NAME
       git-format-patch - Prepare patches for e-mail submission

SYNOPSIS
       git format-patch [-k] [(-o|--output-directory) <dir> | --stdout]
                          [--no-thread | --thread[=<style>]]
                          [(--attach|--inline)[=<boundary>] | --no-attach]
                          [-s | --signoff]
                          [--signature=<signature> | --no-signature]
                          [-n | --numbered | -N | --no-numbered]
                          [--start-number <n>] [--numbered-files]
                          [--in-reply-to=Message-Id] [--suffix=.<sfx>]
                          [--ignore-if-in-upstream]
                          [--subject-prefix=Subject-Prefix] [(--reroll-count|-v) <n>]
                          [--to=<email>] [--cc=<email>]
                          [--[no-]cover-letter] [--quiet] [--notes[=<ref>]]
                          [<common diff options>]
                          [ <since> | <revision range> ]


DESCRIPTION
       Prepare each commit with its patch in one file per commit, formatted to resemble UNIX mailbox format. The
       output of this command is convenient for e-mail submission or for use with git am.

       There are two ways to specify which commits to operate on.

        1. A single commit, <since>, specifies that the commits leading to the tip of the current branch that are not
           in the history that leads to the <since> to be output.

        2. Generic <revision range> expression (see "SPECIFYING REVISIONS" section in gitrevisions(7)) means the
           commits in the specified range.

       The first rule takes precedence in the case of a single <commit>. To apply the second rule, i.e., format
       everything since the beginning of history up until <commit>, use the --root option: git format-patch --root
       <commit>. If you want to format only <commit> itself, you can do this with git format-patch -1 <commit>.

       By default, each output file is numbered sequentially from 1, and uses the first line of the commit message
       (massaged for pathname safety) as the filename. With the --numbered-files option, the output file names will
       only be numbers, without the first line of the commit appended. The names of the output files are printed to
       standard output, unless the --stdout option is specified.

       If -o is specified, output files are created in <dir>. Otherwise they are created in the current working
       directory.

       By default, the subject of a single patch is "[PATCH] " followed by the concatenation of lines from the commit
       message up to the first blank line (see the DISCUSSION section of git-commit(1)).

       When multiple patches are output, the subject prefix will instead be "[PATCH n/m] ". To force 1/1 to be added
       for a single patch, use -n. To omit patch numbers from the subject, use -N.

       If given --thread, git-format-patch will generate In-Reply-To and References headers to make the second and
       subsequent patch mails appear as replies to the first mail; this also generates a Message-Id header to
       reference.

OPTIONS
       -p, --no-stat

           Generate a diff using the "histogram diff" algorithm.

       --diff-algorithm={patience|minimal|histogram|myers}
           Choose a diff algorithm. The variants are as follows:

           default, myers
               The basic greedy diff algorithm. Currently, this is the default.

           minimal
               Spend extra time to make sure the smallest possible diff is produced.

           patience
               Use "patience diff" algorithm when generating patches.

           histogram
               This algorithm extends the patience algorithm to "support low-occurrence common elements".

           For instance, if you configured diff.algorithm variable to a non-default value and want to use the default
           one, then you have to use --diff-algorithm=default option.

       --stat[=<width>[,<name-width>[,<count>]]]
           Generate a diffstat. By default, as much space as necessary will be used for the filename part, and the
           rest for the graph part. Maximum width defaults to terminal width, or 80 columns if not connected to a
           terminal, and can be overridden by <width>. The width of the filename part can be limited by giving
           another width <name-width> after a comma. The width of the graph part can be limited by using
           --stat-graph-width=<width> (affects all commands generating a stat graph) or by setting
           diff.statGraphWidth=<width> (does not affect git format-patch). By giving a third parameter <count>, you
           can limit the output to the first <count> lines, followed by ...  if there are more.

           These parameters can also be set individually with --stat-width=<width>, --stat-name-width=<name-width>
           and --stat-count=<count>.

       --numstat
           Similar to --stat, but shows number of added and deleted lines in decimal notation and pathname without
           abbreviation, to make it more machine friendly. For binary files, outputs two - instead of saying 0 0.

       --shortstat
           Output only the last line of the --stat format containing total number of modified files, as well as
           number of added and deleted lines.

       --dirstat[=<param1,param2,...>]
           Output the distribution of relative amount of changes for each sub-directory. The behavior of --dirstat
           can be customized by passing it a comma separated list of parameters. The defaults are controlled by the
           diff.dirstat configuration variable (see git-config(1)). The following parameters are available:

           changes
               Compute the dirstat numbers by counting the lines that have been removed from the source, or added to
               the destination. This ignores the amount of pure code movements within a file. In other words,
               rearranging lines in a file is not counted as much as other changes. This is the default behavior when
               no parameter is given.

           lines
               Compute the dirstat numbers by doing the regular line-based diff analysis, and summing the
               removed/added line counts. (For binary files, count 64-byte chunks instead, since binary files have no
               specified with the noncumulative parameter.

           <limit>
               An integer parameter specifies a cut-off percent (3% by default). Directories contributing less than
               this percentage of the changes are not shown in the output.

           Example: The following will count changed files, while ignoring directories with less than 10% of the
           total amount of changed files, and accumulating child directory counts in the parent directories:
           --dirstat=files,10,cumulative.

       --summary
           Output a condensed summary of extended header information such as creations, renames and mode changes.

       --no-renames
           Turn off rename detection, even when the configuration file gives the default to do so.

       --full-index
           Instead of the first handful of characters, show the full pre- and post-image blob object names on the
           "index" line when generating patch format output.

       --binary
           In addition to --full-index, output a binary diff that can be applied with git-apply.

       --abbrev[=<n>]
           Instead of showing the full 40-byte hexadecimal object name in diff-raw format output and diff-tree header
           lines, show only a partial prefix. This is independent of the --full-index option above, which controls
           the diff-patch output format. Non default number of digits can be specified with --abbrev=<n>.

       -B[<n>][/<m>], --break-rewrites[=[<n>][/<m>]]
           Break complete rewrite changes into pairs of delete and create. This serves two purposes:

           It affects the way a change that amounts to a total rewrite of a file not as a series of deletion and
           insertion mixed together with a very few lines that happen to match textually as the context, but as a
           single deletion of everything old followed by a single insertion of everything new, and the number m
           controls this aspect of the -B option (defaults to 60%).  -B/70% specifies that less than 30% of the
           original should remain in the result for Git to consider it a total rewrite (i.e. otherwise the resulting
           patch will be a series of deletion and insertion mixed together with context lines).

           When used with -M, a totally-rewritten file is also considered as the source of a rename (usually -M only
           considers a file that disappeared as the source of a rename), and the number n controls this aspect of the
           -B option (defaults to 50%).  -B20% specifies that a change with addition and deletion compared to 20% or
           more of the file’s size are eligible for being picked up as a possible source of a rename to another file.

       -M[<n>], --find-renames[=<n>]
           Detect renames. If n is specified, it is a threshold on the similarity index (i.e. amount of
           addition/deletions compared to the file’s size). For example, -M90% means Git should consider a delete/add
           pair to be a rename if more than 90% of the file hasn’t changed. Without a % sign, the number is to be
           read as a fraction, with a decimal point before it. I.e., -M5 becomes 0.5, and is thus the same as -M50%.
           Similarly, -M05 is the same as -M5%. To limit detection to exact renames, use -M100%.

       -C[<n>], --find-copies[=<n>]
           Detect copies as well as renames. See also --find-copies-harder. If n is specified, it has the same
           meaning as for -M<n>.


           When used together with -B, omit also the preimage in the deletion part of a delete/create pair.

       -l<num>
           The -M and -C options require O(n^2) processing time where n is the number of potential rename/copy
           targets. This option prevents rename/copy detection from running if the number of rename/copy targets
           exceeds the specified number.

       -O<orderfile>
           Output the patch in the order specified in the <orderfile>, which has one shell glob pattern per line.

       -a, --text
           Treat all files as text.

       --ignore-space-at-eol
           Ignore changes in whitespace at EOL.

       -b, --ignore-space-change
           Ignore changes in amount of whitespace. This ignores whitespace at line end, and considers all other
           sequences of one or more whitespace characters to be equivalent.

       -w, --ignore-all-space
           Ignore whitespace when comparing lines. This ignores differences even if one line has whitespace where the
           other line has none.

       --inter-hunk-context=<lines>
           Show the context between diff hunks, up to the specified number of lines, thereby fusing hunks that are
           close to each other.

       -W, --function-context
           Show whole surrounding functions of changes.

       --ext-diff
           Allow an external diff helper to be executed. If you set an external diff driver with gitattributes(5),
           you need to use this option with git-log(1) and friends.

       --no-ext-diff
           Disallow external diff drivers.

       --textconv, --no-textconv
           Allow (or disallow) external text conversion filters to be run when comparing binary files. See
           gitattributes(5) for details. Because textconv filters are typically a one-way conversion, the resulting
           diff is suitable for human consumption, but cannot be applied. For this reason, textconv filters are
           enabled by default only for git-diff(1) and git-log(1), but not for git-format-patch(1) or diff plumbing
           commands.

       --ignore-submodules[=<when>]
           Ignore changes to submodules in the diff generation. <when> can be either "none", "untracked", "dirty" or
           "all", which is the default. Using "none" will consider the submodule modified when it either contains
           untracked or modified files or its HEAD differs from the commit recorded in the superproject and can be
           used to override any settings of the ignore option in git-config(1) or gitmodules(5). When "untracked" is
           used submodules are not considered dirty when they only contain untracked content (but they are still
           scanned for modified content). Using "dirty" ignores all changes to the work tree of submodules, only
           changes to the commits stored in the superproject are shown (this was the behavior until 1.7.0). Using

       -<n>
           Prepare patches from the topmost <n> commits.

       -o <dir>, --output-directory <dir>
           Use <dir> to store the resulting files, instead of the current working directory.

       -n, --numbered
           Name output in [PATCH n/m] format, even with a single patch.

       -N, --no-numbered
           Name output in [PATCH] format.

       --start-number <n>
           Start numbering the patches at <n> instead of 1.

       --numbered-files
           Output file names will be a simple number sequence without the default first line of the commit appended.

       -k, --keep-subject
           Do not strip/add [PATCH] from the first line of the commit log message.

       -s, --signoff
           Add Signed-off-by: line to the commit message, using the committer identity of yourself.

       --stdout
           Print all commits to the standard output in mbox format, instead of creating a file for each one.

       --attach[=<boundary>]
           Create multipart/mixed attachment, the first part of which is the commit message and the patch itself in
           the second part, with Content-Disposition: attachment.

       --no-attach
           Disable the creation of an attachment, overriding the configuration setting.

       --inline[=<boundary>]
           Create multipart/mixed attachment, the first part of which is the commit message and the patch itself in
           the second part, with Content-Disposition: inline.

       --thread[=<style>], --no-thread
           Controls addition of In-Reply-To and References headers to make the second and subsequent mails appear as
           replies to the first. Also controls generation of the Message-Id header to reference.

           The optional <style> argument can be either shallow or deep.  shallow threading makes every mail a reply
           to the head of the series, where the head is chosen from the cover letter, the --in-reply-to, and the
           first patch mail, in this order.  deep threading makes every mail a reply to the previous one.

           The default is --no-thread, unless the format.thread configuration is set. If --thread is specified
           without a style, it defaults to the style specified by format.thread if any, or else shallow.

           Beware that the default for git send-email is to thread emails itself. If you want git format-patch to
           take care of threading, you will want to ensure that threading is disabled for git send-email.

       --in-reply-to=Message-Id
       -v <n>, --reroll-count=<n>
           Mark the series as the <n>-th iteration of the topic. The output filenames have v<n> pretended to them,
           and the subject prefix ("PATCH" by default, but configurable via the --subject-prefix option) has ` v<n>`
           appended to it. E.g.  --reroll-count=4 may produce v4-0001-add-makefile.patch file that has "Subject:
           [PATCH v4 1/20] Add makefile" in it.

       --to=<email>
           Add a To: header to the email headers. This is in addition to any configured headers, and may be used
           multiple times. The negated form --no-to discards all To: headers added so far (from config or command
           line).

       --cc=<email>
           Add a Cc: header to the email headers. This is in addition to any configured headers, and may be used
           multiple times. The negated form --no-cc discards all Cc: headers added so far (from config or command
           line).

       --add-header=<header>
           Add an arbitrary header to the email headers. This is in addition to any configured headers, and may be
           used multiple times. For example, --add-header="Organization: git-foo". The negated form --no-add-header
           discards all (To:, Cc:, and custom) headers added so far from config or command line.

       --[no-]cover-letter
           In addition to the patches, generate a cover letter file containing the shortlog and the overall diffstat.
           You can fill in a description in the file before sending it out.

       --notes[=<ref>]
           Append the notes (see git-notes(1)) for the commit after the three-dash line.

           The expected use case of this is to write supporting explanation for the commit that does not belong to
           the commit log message proper, and include it with the patch submission. While one can simply write these
           explanations after format-patch has run but before sending, keeping them as Git notes allows them to be
           maintained between versions of the patch series (but see the discussion of the notes.rewrite configuration
           options in git-notes(1) to use this workflow).

       --[no]-signature=<signature>
           Add a signature to each message produced. Per RFC 3676 the signature is separated from the body by a line
           with '-- ' on it. If the signature option is omitted the signature defaults to the Git version number.

       --suffix=.<sfx>
           Instead of using .patch as the suffix for generated filenames, use specified suffix. A common alternative
           is --suffix=.txt. Leaving this empty will remove the .patch suffix.

           Note that the leading character does not have to be a dot; for example, you can use --suffix=-patch to get
           0001-description-of-my-change-patch.

       --quiet
           Do not print the names of the generated files to standard output.

       --no-binary
           Do not output contents of changes in binary files, instead display a notice that those files changed.
           Patches generated using this option cannot be applied properly, but they are still useful for code review.

       --root
           Treat the revision argument as a <revision range>, even if it is just a single commit (that would normally

                   numbered = auto
                   to = <email>
                   cc = <email>
                   attach [ = mime-boundary-string ]
                   signoff = true
                   coverletter = auto


DISCUSSION
       The patch produced by git format-patch is in UNIX mailbox format, with a fixed "magic" time stamp to indicate
       that the file is output from format-patch rather than a real mailbox, like so:

           From 8f72bad1baf19a53459661343e21d6491c3908d3 Mon Sep 17 00:00:00 2001
           From: Tony Luck <[email protected]>
           Date: Tue, 13 Jul 2010 11:42:54 -0700
           Subject: [PATCH] =?UTF-8?q?[IA64]=20Put=20ia64=20config=20files=20on=20the=20?=
            =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig=20diet?=
           MIME-Version: 1.0
           Content-Type: text/plain; charset=UTF-8
           Content-Transfer-Encoding: 8bit

           arch/arm config files were slimmed down using a python script
           (See commit c2330e286f68f1c408b4aa6515ba49d57f05beae comment)

           Do the same for ia64 so we can have sleek & trim looking
           ...


       Typically it will be placed in a MUA’s drafts folder, edited to add timely commentary that should not go in
       the changelog after the three dashes, and then sent as a message whose body, in our example, starts with
       "arch/arm config files were...". On the receiving end, readers can save interesting patches in a UNIX mailbox
       and apply them with git-am(1).

       When a patch is part of an ongoing discussion, the patch generated by git format-patch can be tweaked to take
       advantage of the git am --scissors feature. After your response to the discussion comes a line that consists
       solely of "-- >8 --" (scissors and perforation), followed by the patch with unnecessary header fields removed:

           ...
           > So we should do such-and-such.

           Makes sense to me.  How about this patch?

           -- >8 --
           Subject: [IA64] Put ia64 config files on the Uwe Kleine-König diet

           arch/arm config files were slimmed down using a python script
           ...


       When sending a patch this way, most often you are sending your own patch, so in addition to the "From $SHA1
       $magic_timestamp" marker you should omit From: and Date: lines from the patch file. The patch title is likely
       to be different from the subject of the discussion the patch is in response to, so it is likely that you would
       want to keep the Subject: line, like the example above.

       ·   Save that patch to a file in UNIX mailbox format. Call it a.patch, say.

       ·   Apply it:

               $ git fetch <project> master:test-apply
               $ git checkout test-apply
               $ git reset --hard
               $ git am a.patch

       If it does not apply correctly, there can be various reasons.

       ·   The patch itself does not apply cleanly. That is bad but does not have much to do with your MUA. You might
           want to rebase the patch with git-rebase(1) before regenerating it in this case.

       ·   The MUA corrupted your patch; "am" would complain that the patch does not apply. Look in the
           .git/rebase-apply/ subdirectory and see what patch file contains and check for the common corruption
           patterns mentioned above.

       ·   While at it, check the info and final-commit files as well. If what is in final-commit is not exactly what
           you would want to see in the commit log message, it is very likely that the receiver would end up hand
           editing the log message when applying your patch. Things like "Hi, this is my first patch.\n" in the patch
           e-mail should come after the three-dash line that signals the end of the commit message.

MUA-SPECIFIC HINTS
       Here are some hints on how to successfully submit patches inline using various mailers.

   GMail
       GMail does not have any way to turn off line wrapping in the web interface, so it will mangle any emails that
       you send. You can however use "git send-email" and send your patches through the GMail SMTP server, or use any
       IMAP email client to connect to the google IMAP server and forward the emails through that.

       For hints on using git send-email to send your patches through the GMail SMTP server, see the EXAMPLE section
       of git-send-email(1).

       For hints on submission using the IMAP interface, see the EXAMPLE section of git-imap-send(1).

   Thunderbird
       By default, Thunderbird will both wrap emails as well as flag them as being format=flowed, both of which will
       make the resulting email unusable by Git.

       There are three different approaches: use an add-on to turn off line wraps, configure Thunderbird to not
       mangle patches, or use an external editor to keep Thunderbird from mangling the patches.

       Approach #1 (add-on)
           Install the Toggle Word Wrap add-on that is available from
           https://addons.mozilla.org/thunderbird/addon/toggle-word-wrap/ It adds a menu entry "Enable Word Wrap" in
           the composer’s "Options" menu that you can tick off. Now you can compose the message as you otherwise do
           (cut + paste, git format-patch | git imap-send, etc), but you have to insert line breaks manually in any
           text that you type.

       Approach #2 (configuration)
           Three steps:

            1. Configure your mail server composition as plain text: Edit...Account Settings...Composition &

           After that is done, you should be able to compose email as you otherwise would (cut + paste, git
           format-patch | git imap-send, etc), and the patches will not be mangled.

       Approach #3 (external editor)
           The following Thunderbird extensions are needed: AboutConfig from http://aboutconfig.mozdev.org/ and
           External Editor from http://globs.org/articles.php?lng=en&pg=8

            1. Prepare the patch as a text file using your method of choice.

            2. Before opening a compose window, use Edit→Account Settings to uncheck the "Compose messages in HTML
               format" setting in the "Composition & Addressing" panel of the account to be used to send the patch.

            3. In the main Thunderbird window, before you open the compose window for the patch, use
               Tools→about:config to set the following to the indicated values:

                           mailnews.send_plaintext_flowed  => false
                           mailnews.wraplength             => 0


            4. Open a compose window and click the external editor icon.

            5. In the external editor window, read in the patch file and exit the editor normally.

           Side note: it may be possible to do step 2 with about:config and the following settings but no one’s tried
           yet.

                       mail.html_compose                       => false
                       mail.identity.default.compose_html      => false
                       mail.identity.id?.compose_html          => false


           There is a script in contrib/thunderbird-patch-inline which can help you include patches with Thunderbird
           in an easy way. To use it, do the steps above and then use the script as the external editor.

   KMail
       This should help you to submit patches inline using KMail.

        1. Prepare the patch as a text file.

        2. Click on New Mail.

        3. Go under "Options" in the Composer window and be sure that "Word wrap" is not set.

        4. Use Message → Insert file... and insert the patch.

        5. Back in the compose window: add whatever other text you wish to the message, complete the addressing and
           subject fields, and press send.

EXAMPLES
       ·   Extract commits between revisions R1 and R2, and apply them on top of the current branch using git am to
           cherry-pick them:

               $ git format-patch -k --stdout R1..R2 | git am -3 -k


       ·   The same as the previous one:

               $ git format-patch -M -B origin

           Additionally, it detects and handles renames and complete rewrites intelligently to produce a renaming
           patch. A renaming patch reduces the amount of text output, and generally makes it easier to review. Note
           that non-Git "patch" programs won’t understand renaming patches, so use it only when you know the
           recipient uses Git to apply your patch.

       ·   Extract three topmost commits from the current branch and format them as e-mailable patches:

               $ git format-patch -3


SEE ALSO
       git-am(1), git-send-email(1)

GIT
       Part of the git(1) suite



Git 1.8.3.1                                           03/23/2016                                  GIT-FORMAT-PATCH(1)