|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFIGURATION | DISCUSSION | MUA-SPECIFIC HINTS | BASE TREE INFORMATION | EXAMPLES | CAVEATS | SEE ALSO | GIT | COLOPHON |
|
|
|
GIT-FORMAT-PATCH(1) Git Manual GIT-FORMAT-PATCH(1)
git-format-patch - Prepare patches for e-mail submission
git format-patch [-k] [(-o|--output-directory) <dir> | --stdout]
[--no-thread | --thread[=<style>]]
[(--attach|--inline)[=<boundary>] | --no-attach]
[-s | --signoff]
[--signature=<signature> | --no-signature]
[--signature-file=<file>]
[-n | --numbered | -N | --no-numbered]
[--start-number <n>] [--numbered-files]
[--in-reply-to=<message-id>] [--suffix=.<sfx>]
[--ignore-if-in-upstream] [--always]
[--cover-from-description=<mode>]
[--rfc[=<rfc>]] [--subject-prefix=<subject-prefix>]
[(--reroll-count|-v) <n>]
[--to=<email>] [--cc=<email>]
[--[no-]cover-letter] [--quiet]
[--[no-]encode-email-headers]
[--no-notes | --notes[=<ref>]]
[--interdiff=<previous>]
[--range-diff=<previous> [--creation-factor=<percent>]]
[--filename-max-length=<n>]
[--progress]
[<common-diff-options>]
[ <since> | <revision-range> ]
Prepare each non-merge commit with its "patch" in one "message"
per commit, formatted to resemble a UNIX mailbox. The output of
this command is convenient for e-mail submission or for use with
git am.
A "message" generated by the command consists of three parts:
• A brief metadata header that begins with From <commit> with a
fixed Mon Sep 17 00:00:00 2001 datestamp to help programs like
"file(1)" to recognize that the file is an output from this
command, fields that record the author identity, the author
date, and the title of the change (taken from the first
paragraph of the commit log message).
• The second and subsequent paragraphs of the commit log
message.
• The "patch", which is the "diff -p --stat" output (see
git-diff(1)) between the commit and its parent.
The log message and the patch are separated by a line with a
three-dash line.
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. The default
path can be set with the format.outputDirectory configuration
option. The -o option takes precedence over
format.outputDirectory. To store patches in the current working
directory even when format.outputDirectory points elsewhere, use
-o .. All directory components will be created.
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.
-p, --no-stat
Generate plain patches without any diffstats.
-U<n>, --unified=<n>
Generate diffs with <n> lines of context instead of the usual
three.
--output=<file>
Output to a specific file instead of stdout.
--output-indicator-new=<char>, --output-indicator-old=<char>,
--output-indicator-context=<char>
Specify the character used to indicate new, old or context
lines in the generated patch. Normally they are +, - and ' '
respectively.
--indent-heuristic
Enable the heuristic that shifts diff hunk boundaries to make
patches easier to read. This is the default.
--no-indent-heuristic
Disable the indent heuristic.
--minimal
Spend extra time to make sure the smallest possible diff is
produced.
--patience
Generate a diff using the "patience diff" algorithm.
--histogram
Generate a diff using the "histogram diff" algorithm.
--anchored=<text>
Generate a diff using the "anchored diff" algorithm.
This option may be specified more than once.
If a line exists in both the source and destination, exists
only once, and starts with <text>, this algorithm attempts to
prevent it from appearing as a deletion or addition in the
output. It uses the "patience diff" algorithm internally.
--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 the 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 or by setting
diff.statNameWidth=<name-width>. The width of the graph part
can be limited by using --stat-graph-width=<graph-width> or by
setting diff.statGraphWidth=<graph-width>. Using --stat or
--stat-graph-width affects all commands generating a stat
graph, while setting diff.statNameWidth or diff.statGraphWidth
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>.
--compact-summary
Output a condensed summary of extended header information such
as file creations or deletions ("new" or "gone", optionally +l
if it’s a symlink) and mode changes (+x or -x for adding or
removing executable bit respectively) in diffstat. The
information is put between the filename part and the graph
part. Implies --stat.
--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.
-X [<param>,...], --dirstat[=<param>,...]
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 natural concept of
lines). This is a more expensive --dirstat behavior than
the changes behavior, but it does count rearranged lines
within a file as much as other changes. The resulting
output is consistent with what you get from the other
--*stat options.
files
Compute the dirstat numbers by counting the number of
files changed. Each changed file counts equally in the
dirstat analysis. This is the computationally cheapest
--dirstat behavior, since it does not have to look at the
file contents at all.
cumulative
Count changes in a child directory for the parent
directory as well. Note that when using cumulative, the
sum of the percentages reported may exceed 100%. The
default (non-cumulative) behavior can be 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.
--cumulative
Synonym for --dirstat=cumulative.
--dirstat-by-file[=<param>,...]
Synonym for --dirstat=files,<param>,....
--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.
--[no-]rename-empty
Whether to use empty blobs as rename source.
--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 the
shortest prefix that is at least <n> hexdigits long that
uniquely refers the object. In diff-patch output format,
--full-index takes higher precedence, i.e. if --full-index is
specified, full blob names will be shown regardless of
--abbrev. 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%. The default similarity index is 50%.
-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>.
--find-copies-harder
For performance reasons, by default, -C option finds copies
only if the original file of the copy was modified in the same
changeset. This flag makes the command inspect unmodified
files as candidates for the source of copy. This is a very
expensive operation for large projects, so use it with
caution. Giving more than one -C option has the same effect.
-D, --irreversible-delete
Omit the preimage for deletes, i.e. print only the header but
not the diff between the preimage and /dev/null. The resulting
patch is not meant to be applied with patch or git apply; this
is solely for people who want to just concentrate on reviewing
the text after the change. In addition, the output obviously
lacks enough information to apply such a patch in reverse,
even manually, hence the name of the option.
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 involve some preliminary steps that can
detect subsets of renames/copies cheaply, followed by an
exhaustive fallback portion that compares all remaining
unpaired destinations to all relevant sources. (For renames,
only remaining unpaired sources are relevant; for copies, all
original sources are relevant.) For N sources and
destinations, this exhaustive check is O(N^2). This option
prevents the exhaustive portion of rename/copy detection from
running if the number of source/destination files involved
exceeds the specified number. Defaults to diff.renameLimit.
Note that a value of 0 is treated as unlimited.
-O<orderfile>
Control the order in which files appear in the output. This
overrides the diff.orderFile configuration variable (see
git-config(1)). To cancel diff.orderFile, use -O/dev/null.
The output order is determined by the order of glob patterns
in <orderfile>. All files with pathnames that match the first
pattern are output first, all files with pathnames that match
the second pattern (but not the first) are output next, and so
on. All files with pathnames that do not match any pattern are
output last, as if there was an implicit match-all pattern at
the end of the file. If multiple pathnames have the same rank
(they match the same pattern but no earlier patterns), their
output order relative to each other is the normal order.
<orderfile> is parsed as follows:
• Blank lines are ignored, so they can be used as separators
for readability.
• Lines starting with a hash ("#") are ignored, so they can
be used for comments. Add a backslash ("\") to the
beginning of the pattern if it starts with a hash.
• Each other line contains a single pattern.
Patterns have the same syntax and semantics as patterns used
for fnmatch(3) without the FNM_PATHNAME flag, except a
pathname also matches a pattern if removing any number of the
final pathname components matches the pattern. For example,
the pattern "foo*bar" matches "fooasdfbar" and
"foo/bar/baz/asdf" but not "foobarx".
--skip-to=<file>, --rotate-to=<file>
Discard the files before the named <file> from the output
(i.e. skip to), or move them to the end of the output (i.e.
rotate to). These options were invented primarily for the use
of the git difftool command, and may not be very useful
otherwise.
--relative[=<path>], --no-relative
When run from a subdirectory of the project, it can be told to
exclude changes outside the directory and show pathnames
relative to it with this option. When you are not in a
subdirectory (e.g. in a bare repository), you can name which
subdirectory to make the output relative to by giving a <path>
as an argument. --no-relative can be used to countermand both
diff.relative config option and previous --relative.
-a, --text
Treat all files as text.
--ignore-cr-at-eol
Ignore carriage-return at the end of line when doing a
comparison.
--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.
--ignore-blank-lines
Ignore changes whose lines are all blank.
-I<regex>, --ignore-matching-lines=<regex>
Ignore changes whose all lines match <regex>. This option may
be specified more than once.
--inter-hunk-context=<number>
Show the context between diff hunks, up to the specified
<number> of lines, thereby fusing hunks that are close to each
other. Defaults to diff.interHunkContext or 0 if the config
option is unset.
-W, --function-context
Show whole function as context lines for each change. The
function names are determined in the same way as git diff
works out patch hunk headers (see "Defining a custom
hunk-header" in gitattributes(5)).
--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[=(none|untracked|dirty|all)]
Ignore changes to submodules in the diff generation. all 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 all hides all changes to submodules.
--src-prefix=<prefix>
Show the given source <prefix> instead of "a/".
--dst-prefix=<prefix>
Show the given destination <prefix> instead of "b/".
--no-prefix
Do not show any source or destination prefix.
--default-prefix
Use the default source and destination prefixes ("a/" and
"b/"). This overrides configuration variables such as
diff.noprefix, diff.srcPrefix, diff.dstPrefix, and
diff.mnemonicPrefix (see git-config(1)).
--line-prefix=<prefix>
Prepend an additional <prefix> to every line of output.
--ita-invisible-in-index
By default entries added by git add -N appear as an existing
empty file in git diff and a new file in git diff --cached.
This option makes the entry appear as a new file in git diff
and non-existent in git diff --cached. This option could be
reverted with --ita-visible-in-index. Both options are
experimental and could be removed in future.
For more detailed explanation on these common options, see also
gitdiffcore(7).
-<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 a Signed-off-by trailer to the commit message, using the
committer identity of yourself. See the signoff option in
git-commit(1) for more information.
--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. --thread without an argument is
equivalent to --thread=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>
Make the first mail (or all the mails with --no-thread) appear
as a reply to the given <message-id>, which avoids breaking
threads to provide a new patch series.
--ignore-if-in-upstream
Do not include a patch that matches a commit in
<until>..<since>. This will examine all patches reachable from
<since> but not from <until> and compare them with the patches
being generated, and any patch that matches is ignored.
--always
Include patches for commits that do not introduce any change,
which are omitted by default.
--cover-from-description=<mode>
Controls which parts of the cover letter will be automatically
populated using the branch’s description.
If <mode> is message or default, the cover letter subject will
be populated with placeholder text. The body of the cover
letter will be populated with the branch’s description. This
is the default mode when no configuration nor command line
option is specified.
If <mode> is subject, the first paragraph of the branch
description will populate the cover letter subject. The
remainder of the description will populate the body of the
cover letter.
If <mode> is auto, if the first paragraph of the branch
description is greater than 100 bytes, then the mode will be
message, otherwise subject will be used.
If <mode> is none, both the cover letter subject and body will
be populated with placeholder text.
--description-file=<file>
Use the contents of <file> instead of the branch’s description
for generating the cover letter.
--subject-prefix=<subject-prefix>
Instead of the standard [PATCH] prefix in the subject line,
instead use [<subject-prefix>]. This can be used to name a
patch series, and can be combined with the --numbered option.
The configuration variable format.subjectPrefix may also be
used to configure a subject prefix to apply to a given
repository for all patches. This is often useful on mailing
lists which receive patches for several repositories and can
be used to disambiguate the patches (with a value of e.g.
"PATCH my-project").
--filename-max-length=<n>
Instead of the standard 64 bytes, chomp the generated output
filenames at around <n> bytes (too short a value will be
silently raised to a reasonable length). Defaults to the value
of the format.filenameMaxLength configuration variable, or 64
if unconfigured.
--rfc[=<rfc>]
Prepends the string <rfc> (defaults to "RFC") to the subject
prefix. As the subject prefix defaults to "PATCH", you’ll get
"RFC PATCH" by default.
RFC means "Request For Comments"; use this when sending an
experimental patch for discussion rather than application.
"--rfc=WIP" may also be a useful way to indicate that a patch
is not complete yet ("WIP" stands for "Work In Progress").
If the convention of the receiving community for a particular
extra string is to have it after the subject prefix, the
string <rfc> can be prefixed with a dash ("-") to signal that
the rest of the <rfc> string should be appended to the subject
prefix instead, e.g., --rfc='-(WIP)' results in "PATCH (WIP)".
-v <n>, --reroll-count=<n>
Mark the series as the <n>-th iteration of the topic. The
output filenames have v<n> prepended 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. <n>
does not have to be an integer (e.g. "--reroll-count=4.4", or
"--reroll-count=4rev2" are allowed), but the downside of using
such a reroll-count is that the range-diff/interdiff with the
previous version does not state exactly which version the new
iteration is compared against.
--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).
--from, --from=<ident>
Use ident in the From: header of each commit email. If the
author ident of the commit is not textually identical to the
provided ident, place a From: header in the body of the
message with the original author. If no ident is given, use
the committer ident.
Note that this option is only useful if you are actually
sending the emails and want to identify yourself as the
sender, but retain the original author (and git am will
correctly pick up the in-body header). Note also that git
send-email already handles this transformation for you, and
this option should not be used if you are feeding the result
to git send-email.
--[no-]force-in-body-from
With the e-mail sender specified via the --from option, by
default, an in-body "From:" to identify the real author of the
commit is added at the top of the commit log message if the
sender is different from the author. With this option, the
in-body "From:" is added even when the sender and the author
have the same name and address, which may help if the mailing
list software mangles the sender’s identity. Defaults to the
value of the format.forceInBodyFrom configuration variable.
--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 branch description, shortlog and the overall
diffstat. You can fill in a description in the file before
sending it out.
--encode-email-headers, --no-encode-email-headers
Encode email headers that have non-ASCII characters with
"Q-encoding" (described in RFC 2047), instead of outputting
the headers verbatim. Defaults to the value of the
format.encodeEmailHeaders configuration variable.
--interdiff=<previous>
As a reviewer aid, insert an interdiff into the cover letter,
or as commentary of the lone patch of a 1-patch series,
showing the differences between the previous version of the
patch series and the series currently being formatted.
previous is a single revision naming the tip of the previous
series which shares a common base with the series being
formatted (for example git format-patch --cover-letter
--interdiff=feature/v1 -3 feature/v2).
--range-diff=<previous>
As a reviewer aid, insert a range-diff (see git-range-diff(1))
into the cover letter, or as commentary of the lone patch of a
1-patch series, showing the differences between the previous
version of the patch series and the series currently being
formatted. previous can be a single revision naming the tip
of the previous series if it shares a common base with the
series being formatted (for example git format-patch
--cover-letter --range-diff=feature/v1 -3 feature/v2), or a
revision range if the two versions of the series are disjoint
(for example git format-patch --cover-letter
--range-diff=feature/v1~3..feature/v1 -3 feature/v2).
Note that diff options passed to the command affect how the
primary product of format-patch is generated, and they are not
passed to the underlying range-diff machinery used to generate
the cover-letter material (this may change in the future).
--creation-factor=<percent>
Used with --range-diff, tweak the heuristic which matches up
commits between the previous and current series of patches by
adjusting the creation/deletion cost fudge factor. See
git-range-diff(1)) for details.
Defaults to 999 (the git-range-diff(1) uses 60), as the use
case is to show comparison with an older iteration of the same
topic and the tool should find more correspondence between the
two sets of patches.
--notes[=<ref>], --no-notes
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).
The default is --no-notes, unless the format.notes
configuration is set.
--[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.
--signature-file=<file>
Works just like --signature except the signature is read from
a file.
--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.
-q, --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.
--zero-commit
Output an all-zero hash in each patch’s From header instead of
the hash of the commit.
--[no-]base[=<commit>]
Record the base tree information to identify the state the
patch series applies to. See the BASE TREE INFORMATION section
below for details. If <commit> is "auto", a base commit is
automatically chosen. The --no-base option overrides a
format.useAutoBase configuration.
--root
Treat the revision argument as a <revision-range>, even if it
is just a single commit (that would normally be treated as a
<since>). Note that root commits included in the specified
range are always formatted as creation patches, independently
of this flag.
--progress
Show progress reports on stderr as patches are generated.
You can specify extra mail header lines to be added to each
message, defaults for the subject prefix and file suffix, number
patches when outputting more than one patch, add "To:" or "Cc:"
headers, configure attachments, change the patch output directory,
and sign off patches with configuration variables.
[format]
headers = "Organization: git-foo\n"
subjectPrefix = CHANGE
suffix = .txt
numbered = auto
to = <email>
cc = <email>
attach [ = mime-boundary-string ]
signOff = true
outputDirectory = <directory>
coverLetter = auto
coverFromDescription = auto
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.
Checking for patch corruption
Many mailers if not set up properly will corrupt whitespace. Here
are two common types of corruption:
• Empty context lines that do not have any whitespace.
• Non-empty context lines that have one extra whitespace at the
beginning.
One way to test if your MUA is set up correctly is:
• Send the patch to yourself, exactly the way you would, except
with To: and Cc: lines that do not contain the list and
maintainer address.
• Save that patch to a file in UNIX mailbox format. Call it
a.patch, say.
• Apply it:
$ git fetch <project> master:test-apply
$ git switch test-apply
$ git restore --source=HEAD --staged --worktree :/
$ 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.
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 & Addressing,
uncheck "Compose Messages in HTML".
2. Configure your general composition window to not wrap.
In Thunderbird 2: Edit..Preferences..Composition, wrap
plain text messages at 0
In Thunderbird 3: Edit..Preferences..Advanced..Config
Editor. Search for "mail.wrap_long_lines". Toggle it to
make sure it is set to false. Also, search for
"mailnews.wraplength" and set the value to 0.
3. Disable the use of format=flowed:
Edit..Preferences..Advanced..Config Editor. Search for
"mailnews.send_plaintext_flowed". Toggle it to make sure
it is set to false.
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 https://mjg.github.io/AboutConfig/ and External Editor
from https://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.
The base tree information block is used for maintainers or third
party testers to know the exact state the patch series applies to.
It consists of the base commit, which is a well-known commit that
is part of the stable part of the project history everybody else
works off of, and zero or more prerequisite patches, which are
well-known patches in flight that is not yet part of the base
commit that need to be applied on top of base commit in
topological order before the patches can be applied.
The base commit is shown as "base-commit: " followed by the 40-hex
of the commit object name. A prerequisite patch is shown as
"prerequisite-patch-id: " followed by the 40-hex patch id, which
can be obtained by passing the patch through the git patch-id
--stable command.
Imagine that on top of the public commit P, you applied well-known
patches X, Y and Z from somebody else, and then built your
three-patch series A, B, C, the history would be like:
---P---X---Y---Z---A---B---C
With git format-patch --base=P -3 C (or variants thereof, e.g.
with --cover-letter or using Z..C instead of -3 C to specify the
range), the base tree information block is shown at the end of the
first message the command outputs (either the first patch, or the
cover letter), like this:
base-commit: P
prerequisite-patch-id: X
prerequisite-patch-id: Y
prerequisite-patch-id: Z
For non-linear topology, such as
---P---X---A---M---C
\ /
Y---Z---B
You can also use git format-patch --base=P -3 C to generate
patches for A, B and C, and the identifiers for P, X, Y, Z are
appended at the end of the first message.
If set --base=auto in cmdline, it will automatically compute the
base commit as the merge base of tip commit of the remote-tracking
branch and revision-range specified in cmdline. For a local
branch, you need to make it to track a remote branch by git branch
--set-upstream-to before using this option.
• 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
• Extract all commits which are in the current branch but not in
the origin branch:
$ git format-patch origin
For each commit a separate file is created in the current
directory.
• Extract all commits that lead to origin since the inception of
the project:
$ git format-patch --root origin
• 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
Note that format-patch will omit merge commits from the output,
even if they are part of the requested range. A simple "patch"
does not include enough information for the receiving end to
reproduce the same merge commit.
git-am(1), git-send-email(1)
Part of the git(1) suite
This page is part of the git (Git distributed version control
system) project. Information about the project can be found at
⟨http://git-scm.com/⟩. If you have a bug report for this manual
page, see ⟨http://git-scm.com/community⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/git/git.git⟩ on 2025-08-11. (At that time,
the date of the most recent commit that was found in the
repository was 2025-08-07.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
Git 2.51.0.rc1 2025-08-07 GIT-FORMAT-PATCH(1)
Pages that refer to this page: git(1), git-am(1), git-apply(1), git-commit(1), git-config(1), git-diff(1), git-diff-files(1), git-diff-index(1), git-diff-pairs(1), git-diff-tree(1), git-format-patch(1), git-imap-send(1), git-interpret-trailers(1), git-log(1), git-send-email(1), git-show(1), stg-email(1), gitweb.conf(5), gitdiffcore(7), giteveryday(7), gittutorial(7), gitworkflows(7)
|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|