NAME¶

git-interpret-trailers - Add or parse structured information in commit messages

SYNOPSIS¶

git interpret-trailers [--in-place] [--trim-empty]


                        [(--trailer (<key>|<key-alias>)[(=|:)<value>])...]


                        [--parse] [<file>...]

DESCRIPTION¶

Add or parse trailer lines that look similar to RFC 822 e-mail headers, at the end of the otherwise free-form part of a commit message. For example, in the following commit message

subject
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Signed-off-by: Alice <alice@example.com>
Signed-off-by: Bob <bob@example.com>

the last two lines starting with "Signed-off-by" are trailers.

This command reads commit messages from either the <file> arguments or the standard input if no <file> is specified. If --parse is specified, the output consists of the parsed trailers coming from the input, without influencing them with any command line options or configuration variables.

Otherwise, this command applies trailer.* configuration variables (which could potentially add new trailers, as well as reposition them), as well as any command line arguments that can override configuration variables (such as --trailer=... which could also add new trailers), to each input file. The result is emitted on the standard output.

This command can also operate on the output of git-format-patch(1), which is more elaborate than a plain commit message. Namely, such output includes a commit message (as above), a "---" divider line, and a patch part. For these inputs, the divider and patch parts are not modified by this command and are emitted as is on the output, unless --no-divider is specified.

Some configuration variables control the way the --trailer arguments are applied to each input and the way any existing trailer in the input is changed. They also make it possible to automatically add some trailers.

By default, a <key>=<value> or <key>:<value> argument given using --trailer will be appended after the existing trailers only if the last trailer has a different (<key>, <value>) pair (or if there is no existing trailer). The <key> and <value> parts will be trimmed to remove starting and trailing whitespace, and the resulting trimmed <key> and <value> will appear in the output like this:

key: value

This means that the trimmed <key> and <value> will be separated by ': ' (one colon followed by one space).

For convenience, a <key-alias> can be configured to make using --trailer shorter to type on the command line. This can be configured using the trailer.<key-alias>.key configuration variable. The <keyAlias> must be a prefix of the full <key> string, although case sensitivity does not matter. For example, if you have

trailer.sign.key "Signed-off-by: "

in your configuration, you only need to specify --trailer="sign: foo" on the command line instead of --trailer="Signed-off-by: foo".

By default the new trailer will appear at the end of all the existing trailers. If there is no existing trailer, the new trailer will appear at the end of the input. A blank line will be added before the new trailer if there isn’t one already.

Existing trailers are extracted from the input by looking for a group of one or more lines that (i) is all trailers, or (ii) contains at least one Git-generated or user-configured trailer and consists of at least 25% trailers. The group must be preceded by one or more empty (or whitespace-only) lines. The group must either be at the end of the input or be the last non-whitespace lines before a line that starts with --- (followed by a space or the end of the line).

When reading trailers, there can be no whitespace before or inside the <key>, but any number of regular space and tab characters are allowed between the <key> and the separator. There can be whitespaces before, inside or after the <value>. The <value> may be split over multiple lines with each subsequent line starting with at least one whitespace, like the "folding" in RFC 822. Example:

key: This is a very long value, with spaces and


  newlines in it.

Note that trailers do not follow (nor are they intended to follow) many of the rules for RFC 822 headers. For example they do not follow the encoding rule.

OPTIONS¶

--in-place

--trim-empty

--trailer <key>[(=|:)<value>]

--where <placement>, --no-where

--if-exists <action>, --no-if-exists

--if-missing <action>, --no-if-missing

--only-trailers

--only-input

--unfold

--parse

--no-divider

CONFIGURATION VARIABLES¶

trailer.separators

trailer.where

trailer.ifexists

trailer.ifmissing

trailer.<keyAlias>.key

trailer.<keyAlias>.where

trailer.<keyAlias>.ifexists

trailer.<keyAlias>.ifmissing

trailer.<keyAlias>.command

trailer.<keyAlias>.cmd

EXAMPLES¶

$ git config trailer.sign.key "Signed-off-by"
$ cat msg.txt
subject
body text
$ git interpret-trailers --trailer 'sign: Alice <alice@example.com>' --trailer 'sign: Bob <bob@example.com>' <msg.txt
subject
body text
Signed-off-by: Alice <alice@example.com>
Signed-off-by: Bob <bob@example.com>

$ cat msg.txt
subject
body text
Signed-off-by: Bob <bob@example.com>
$ git interpret-trailers --trailer 'Acked-by: Alice <alice@example.com>' --in-place msg.txt
$ cat msg.txt
subject
body text
Signed-off-by: Bob <bob@example.com>
Acked-by: Alice <alice@example.com>

$ git format-patch -1
0001-foo.patch
$ git interpret-trailers --trailer 'Cc: Alice <alice@example.com>' --trailer 'Reviewed-by: Bob <bob@example.com>' 0001-foo.patch >0001-bar.patch

$ cat msg1.txt
subject
body text
$ git config trailer.sign.key "Signed-off-by: "
$ git config trailer.sign.ifmissing add
$ git config trailer.sign.ifexists doNothing
$ git config trailer.sign.cmd 'echo "$(git config user.name) <$(git config user.email)>"'
$ git interpret-trailers --trailer sign <msg1.txt
subject
body text
Signed-off-by: Bob <bob@example.com>
$ cat msg2.txt
subject
body text
Signed-off-by: Alice <alice@example.com>
$ git interpret-trailers --trailer sign <msg2.txt
subject
body text
Signed-off-by: Alice <alice@example.com>

$ git config trailer.separators ":#"
$ git config trailer.fix.key "Fix #"
$ echo "subject" | git interpret-trailers --trailer fix=42
subject
Fix #42

$ cat ~/bin/glog-find-author
#!/bin/sh
test -n "$1" && git log --author="$1" --pretty="%an <%ae>" -1 || true
$ cat msg.txt
subject
body text
$ git config trailer.help.key "Helped-by: "
$ git config trailer.help.ifExists "addIfDifferentNeighbor"
$ git config trailer.help.cmd "~/bin/glog-find-author"
$ git interpret-trailers --trailer="help:Junio" --trailer="help:Couder" <msg.txt
subject
body text
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Christian Couder <christian.couder@gmail.com>

$ cat ~/bin/glog-grep
#!/bin/sh
test -n "$1" && git log --grep "$1" --pretty=reference -1 || true
$ cat msg.txt
subject
body text
$ git config trailer.ref.key "Reference-to: "
$ git config trailer.ref.ifExists "replace"
$ git config trailer.ref.cmd "~/bin/glog-grep"
$ git interpret-trailers --trailer="ref:Add copyright notices." <msg.txt
subject
body text
Reference-to: 8bc9a0c769 (Add copyright notices., 2005-04-07)

$ cat msg.txt
subject
body text
see: HEAD~2
$ cat ~/bin/glog-ref
#!/bin/sh
git log -1 --oneline --format="%h (%s)" --abbrev-commit --abbrev=14
$ git config trailer.see.key "See-also: "
$ git config trailer.see.ifExists "replace"
$ git config trailer.see.ifMissing "doNothing"
$ git config trailer.see.cmd "glog-ref"
$ git interpret-trailers --trailer=see <msg.txt
subject
body text
See-also: fe3187489d69c4 (subject of related commit)

$ cat temp.txt
***subject***
***message***
Fixes: Z
Cc: Z
Reviewed-by: Z
Signed-off-by: Z
$ sed -e 's/ Z$/ /' temp.txt > commit_template.txt
$ git config commit.template commit_template.txt
$ cat .git/hooks/commit-msg
#!/bin/sh
git interpret-trailers --trim-empty --trailer "git-version: \$(git describe)" "\$1" > "\$1.new"
mv "\$1.new" "\$1"
$ chmod +x .git/hooks/commit-msg

SEE ALSO¶

git-commit(1), git-format-patch(1), git-config(1)

GIT¶

Part of the git(1) suite