git-interpret-trailers(1) - Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFIGURATION VARIABLES | EXAMPLES | SEE ALSO | GIT | COLOPHON

GIT-INTERPRET-TRAI(1)            Git Manual            GIT-INTERPRET-TRAI(1)

NAME         top

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

SYNOPSIS         top

       git interpret-trailers [options] [(--trailer <token>[(=|:)<value>])...] [<file>...]
       git interpret-trailers [options] [--parse] [<file>...]

DESCRIPTION         top

       Help parsing or adding trailers lines, that look similar to RFC 822
       e-mail headers, at the end of the otherwise free-form part of a
       commit message.

       This command reads some patches or 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.

       Otherwise, this command applies the arguments passed using the
       --trailer option, if any, to the commit message part of each input
       file. The result is emitted on the standard output.

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

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

           token: value

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

       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 after the commit message part of the output, and, if there is
       no line with only spaces at the end of the commit message part, one
       blank line will be added before the new trailer.

       Existing trailers are extracted from the input message by looking for
       a group of one or more lines that (i) are 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 message or be the last non-whitespace lines before a
       line that starts with ---. Such three minus signs start the patch
       part of the message.

       When reading trailers, there can be whitespaces after the token, the
       separator and the value. There can also be whitespaces inside the
       token and the value. The value may be split over multiple lines with
       each subsequent line starting with whitespace, like the "folding" in
       RFC 822.

       Note that trailers do not follow and are not intended to follow many
       rules for RFC 822 headers. For example they do not follow the
       encoding rules and probably many other rules.

OPTIONS         top

       --in-place
           Edit the files in place.

       --trim-empty
           If the <value> part of any trailer contains only whitespace, the
           whole trailer will be removed from the resulting message. This
           applies to existing trailers as well as new trailers.

       --trailer <token>[(=|:)<value>]
           Specify a (<token>, <value>) pair that should be applied as a
           trailer to the input messages. See the description of this
           command.

       --where <placement>, --no-where
           Specify where all new trailers will be added. A setting provided
           with --where overrides all configuration variables and applies to
           all --trailer options until the next occurrence of --where or
           --no-where.

       --if-exists <action>, --no-if-exists
           Specify what action will be performed when there is already at
           least one trailer with the same <token> in the message. A setting
           provided with --if-exists overrides all configuration variables
           and applies to all --trailer options until the next occurrence of
           --if-exists or --no-if-exists.

       --if-missing <action>, --no-if-missing
           Specify what action will be performed when there is no other
           trailer with the same <token> in the message. A setting provided
           with --if-missing overrides all configuration variables and
           applies to all --trailer options until the next occurrence of
           --if-missing or --no-if-missing.

       --only-trailers
           Output only the trailers, not any other parts of the input.

       --only-input
           Output only trailers that exist in the input; do not add any from
           the command-line or by following configured trailer.*  rules.

       --unfold
           Remove any whitespace-continuation in trailers, so that each
           trailer appears on a line by itself with its full content.

       --parse
           A convenience alias for --only-trailers --only-input --unfold.

CONFIGURATION VARIABLES         top

       trailer.separators
           This option tells which characters are recognized as trailer
           separators. By default only : is recognized as a trailer
           separator, except that = is always accepted on the command line
           for compatibility with other git commands.

           The first character given by this option will be the default
           character used when another separator is not specified in the
           config for this trailer.

           For example, if the value for this option is "%=$", then only
           lines using the format <token><sep><value> with <sep> containing
           %, = or $ and then spaces will be considered trailers. And % will
           be the default separator used, so by default trailers will appear
           like: <token>% <value> (one percent sign and one space will
           appear between the token and the value).

       trailer.where
           This option tells where a new trailer will be added.

           This can be end, which is the default, start, after or before.

           If it is end, then each new trailer will appear at the end of the
           existing trailers.

           If it is start, then each new trailer will appear at the start,
           instead of the end, of the existing trailers.

           If it is after, then each new trailer will appear just after the
           last trailer with the same <token>.

           If it is before, then each new trailer will appear just before
           the first trailer with the same <token>.

       trailer.ifexists
           This option makes it possible to choose what action will be
           performed when there is already at least one trailer with the
           same <token> in the message.

           The valid values for this option are: addIfDifferentNeighbor
           (this is the default), addIfDifferent, add, replace or doNothing.

           With addIfDifferentNeighbor, a new trailer will be added only if
           no trailer with the same (<token>, <value>) pair is above or
           below the line where the new trailer will be added.

           With addIfDifferent, a new trailer will be added only if no
           trailer with the same (<token>, <value>) pair is already in the
           message.

           With add, a new trailer will be added, even if some trailers with
           the same (<token>, <value>) pair are already in the message.

           With replace, an existing trailer with the same <token> will be
           deleted and the new trailer will be added. The deleted trailer
           will be the closest one (with the same <token>) to the place
           where the new one will be added.

           With doNothing, nothing will be done; that is no new trailer will
           be added if there is already one with the same <token> in the
           message.

       trailer.ifmissing
           This option makes it possible to choose what action will be
           performed when there is not yet any trailer with the same <token>
           in the message.

           The valid values for this option are: add (this is the default)
           and doNothing.

           With add, a new trailer will be added.

           With doNothing, nothing will be done.

       trailer.<token>.key
           This key will be used instead of <token> in the trailer. At the
           end of this key, a separator can appear and then some space
           characters. By default the only valid separator is :, but this
           can be changed using the trailer.separators config variable.

           If there is a separator, then the key will be used instead of
           both the <token> and the default separator when adding the
           trailer.

       trailer.<token>.where
           This option takes the same values as the trailer.where
           configuration variable and it overrides what is specified by that
           option for trailers with the specified <token>.

       trailer.<token>.ifexists
           This option takes the same values as the trailer.ifexists
           configuration variable and it overrides what is specified by that
           option for trailers with the specified <token>.

       trailer.<token>.ifmissing
           This option takes the same values as the trailer.ifmissing
           configuration variable and it overrides what is specified by that
           option for trailers with the specified <token>.

       trailer.<token>.command
           This option can be used to specify a shell command that will be
           called to automatically add or modify a trailer with the
           specified <token>.

           When this option is specified, the behavior is as if a special
           <token>=<value> argument were added at the beginning of the
           command line, where <value> is taken to be the standard output of
           the specified command with any leading and trailing whitespace
           trimmed off.

           If the command contains the $ARG string, this string will be
           replaced with the <value> part of an existing trailer with the
           same <token>, if any, before the command is launched.

           If some <token>=<value> arguments are also passed on the command
           line, when a trailer.<token>.command is configured, the command
           will also be executed for each of these arguments. And the
           <value> part of these arguments, if any, will be used to replace
           the $ARG string in the command.

EXAMPLES         top

       ·   Configure a sign trailer with a Signed-off-by key, and then add
           two of these trailers to a message:

               $ git config trailer.sign.key "Signed-off-by"
               $ cat msg.txt
               subject

               message
               $ cat msg.txt | git interpret-trailers --trailer 'sign: Alice <alice@example.com>' --trailer 'sign: Bob <bob@example.com>'
               subject

               message

               Signed-off-by: Alice <alice@example.com>
               Signed-off-by: Bob <bob@example.com>

       ·   Use the --in-place option to edit a message file in place:

               $ cat msg.txt
               subject

               message

               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

               message

               Signed-off-by: Bob <bob@example.com>
               Acked-by: Alice <alice@example.com>

       ·   Extract the last commit as a patch, and add a Cc and a
           Reviewed-by trailer to it:

               $ 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

       ·   Configure a sign trailer with a command to automatically add a
           'Signed-off-by: ' with the author information only if there is no
           'Signed-off-by: ' already, and show how it works:

               $ git config trailer.sign.key "Signed-off-by: "
               $ git config trailer.sign.ifmissing add
               $ git config trailer.sign.ifexists doNothing
               $ git config trailer.sign.command 'echo "$(git config user.name) <$(git config user.email)>"'
               $ git interpret-trailers <<EOF
               > EOF

               Signed-off-by: Bob <bob@example.com>
               $ git interpret-trailers <<EOF
               > Signed-off-by: Alice <alice@example.com>
               > EOF

               Signed-off-by: Alice <alice@example.com>

       ·   Configure a fix trailer with a key that contains a # and no space
           after this character, and show how it works:

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

               Fix #42

       ·   Configure a see trailer with a command to show the subject of a
           commit that is related, and show how it works:

               $ git config trailer.see.key "See-also: "
               $ git config trailer.see.ifExists "replace"
               $ git config trailer.see.ifMissing "doNothing"
               $ git config trailer.see.command "git log -1 --oneline --format=\"%h (%s)\" --abbrev-commit --abbrev=14 \$ARG"
               $ git interpret-trailers <<EOF
               > subject
               >
               > message
               >
               > see: HEAD~2
               > EOF
               subject

               message

               See-also: fe3187489d69c4 (subject of related commit)

       ·   Configure a commit template with some trailers with empty values
           (using sed to show and keep the trailing spaces at the end of the
           trailers), then configure a commit-msg hook that uses git
           interpret-trailers to remove trailers with empty values and to
           add a git-version trailer:

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

SEE ALSO         top

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

GIT         top

       Part of the git(1) suite

COLOPHON         top

       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
       2018-02-02.  (At that time, the date of the most recent commit that
       was found in the repository was 2018-01-23.)  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
       man-pages@man7.org

Git 2.14.1.459.g238e48           09/04/2017            GIT-INTERPRET-TRAI(1)

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