{ "mode": "man", "parameter": "git-interpret-trailers", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/git-interpret-trailers/1/json", "generated": "2026-10-22T13:12:49Z", "synopsis": "git interpret-trailers [--in-place] [--trim-empty]\n[(--trailer (|)[(=|:)])...]\n[--parse] [...]", "sections": { "NAME": { "content": "git-interpret-trailers - Add or parse structured information in commit messages\n", "subsections": [] }, "SYNOPSIS": { "content": "git interpret-trailers [--in-place] [--trim-empty]\n[(--trailer (|)[(=|:)])...]\n[--parse] [...]\n\n", "subsections": [] }, "DESCRIPTION": { "content": "Add or parse trailer lines that look similar to RFC 822 e-mail headers, at the end of the\notherwise free-form part of a commit message. For example, in the following commit message\n\nsubject\n\nLorem ipsum dolor sit amet, consectetur adipiscing elit.\n\nSigned-off-by: Alice \nSigned-off-by: Bob \n\n\nthe last two lines starting with \"Signed-off-by\" are trailers.\n\nThis command reads commit messages from either the arguments or the standard input if\nno is specified. If --parse is specified, the output consists of the parsed trailers\ncoming from the input, without influencing them with any command line options or\nconfiguration variables.\n\nOtherwise, this command applies trailer.* configuration variables (which could potentially\nadd new trailers, as well as reposition them), as well as any command line arguments that can\noverride configuration variables (such as --trailer=... which could also add new trailers),\nto each input file. The result is emitted on the standard output.\n\nThis command can also operate on the output of git-format-patch(1), which is more elaborate\nthan a plain commit message. Namely, such output includes a commit message (as above), a\n\"---\" divider line, and a patch part. For these inputs, the divider and patch parts are not\nmodified by this command and are emitted as is on the output, unless --no-divider is\nspecified.\n\nSome configuration variables control the way the --trailer arguments are applied to each\ninput and the way any existing trailer in the input is changed. They also make it possible to\nautomatically add some trailers.\n\nBy default, a = or : argument given using --trailer will be appended\nafter the existing trailers only if the last trailer has a different (, ) pair\n(or if there is no existing trailer). The and parts will be trimmed to remove\nstarting and trailing whitespace, and the resulting trimmed and will appear in\nthe output like this:\n\nkey: value\n\n\nThis means that the trimmed and will be separated by ': ' (one colon followed\nby one space).\n\nFor convenience, a can be configured to make using --trailer shorter to type on\nthe command line. This can be configured using the trailer..key configuration\nvariable. The must be a prefix of the full string, although case sensitivity\ndoes not matter. For example, if you have\n\ntrailer.sign.key \"Signed-off-by: \"\n\n\nin your configuration, you only need to specify --trailer=\"sign: foo\" on the command line\ninstead of --trailer=\"Signed-off-by: foo\".\n\nBy default the new trailer will appear at the end of all the existing trailers. If there is\nno existing trailer, the new trailer will appear at the end of the input. A blank line will\nbe added before the new trailer if there isn’t one already.\n\nExisting trailers are extracted from the input by looking for a group of one or more lines\nthat (i) is all trailers, or (ii) contains at least one Git-generated or user-configured\ntrailer and consists of at least 25% trailers. The group must be preceded by one or more\nempty (or whitespace-only) lines. The group must either be at the end of the input or be the\nlast non-whitespace lines before a line that starts with --- (followed by a space or the end\nof the line).\n\nWhen reading trailers, there can be no whitespace before or inside the , but any number\nof regular space and tab characters are allowed between the and the separator. There\ncan be whitespaces before, inside or after the . The may be split over\nmultiple lines with each subsequent line starting with at least one whitespace, like the\n\"folding\" in RFC 822. Example:\n\nkey: This is a very long value, with spaces and\nnewlines in it.\n\n\nNote that trailers do not follow (nor are they intended to follow) many of the rules for RFC\n822 headers. For example they do not follow the encoding rule.\n", "subsections": [] }, "OPTIONS": { "content": "", "subsections": [ { "name": "--in-place", "content": "Edit the files in place.\n", "long": "--in-place" }, { "name": "--trim-empty", "content": "If the part of any trailer contains only whitespace, the whole trailer will be\nremoved from the output. This applies to existing trailers as well as new trailers.\n\n--trailer [(=|:)]\nSpecify a (, ) pair that should be applied as a trailer to the inputs. See\nthe description of this command.\n", "long": "--trim-empty" }, { "name": "--where , --no-where", "content": "Specify where all new trailers will be added. A setting provided with --where overrides\nthe trailer.where and any applicable trailer..where configuration variables and\napplies to all --trailer options until the next occurrence of --where or --no-where. Upon\nencountering --no-where, clear the effect of any previous use of --where, such that the\nrelevant configuration variables are no longer overridden. Possible placements are after,\nbefore, end or start.\n", "long": "--no-where", "arg": "" }, { "name": "--if-exists , --no-if-exists", "content": "Specify what action will be performed when there is already at least one trailer with the\nsame in the input. A setting provided with --if-exists overrides the\ntrailer.ifExists and any applicable trailer..ifExists configuration variables\nand applies to all --trailer options until the next occurrence of --if-exists or\n--no-if-exists. Upon encountering '--no-if-exists, clear the effect of any previous use\nof '--if-exists, such that the relevant configuration variables are no longer overridden.\nPossible actions are addIfDifferent, addIfDifferentNeighbor, add, replace and doNothing.\n", "long": "--no-if-exists", "arg": "" }, { "name": "--if-missing , --no-if-missing", "content": "Specify what action will be performed when there is no other trailer with the same \nin the input. A setting provided with --if-missing overrides the trailer.ifMissing and\nany applicable trailer..ifMissing configuration variables and applies to all\n--trailer options until the next occurrence of --if-missing or --no-if-missing. Upon\nencountering '--no-if-missing, clear the effect of any previous use of '--if-missing,\nsuch that the relevant configuration variables are no longer overridden. Possible actions\nare doNothing or add.\n", "long": "--no-if-missing", "arg": "" }, { "name": "--only-trailers", "content": "Output only the trailers, not any other parts of the input.\n", "long": "--only-trailers" }, { "name": "--only-input", "content": "Output only trailers that exist in the input; do not add any from the command-line or by\napplying trailer.* configuration variables.\n", "long": "--only-input" }, { "name": "--unfold", "content": "If a trailer has a value that runs over multiple lines (aka \"folded\"), reformat the value\ninto a single line.\n", "long": "--unfold" }, { "name": "--parse", "content": "A convenience alias for --only-trailers --only-input --unfold. This makes it easier to\nonly see the trailers coming from the input without influencing them with any command\nline options or configuration variables, while also making the output machine-friendly\nwith --unfold.\n", "long": "--parse" }, { "name": "--no-divider", "content": "Do not treat --- as the end of the commit message. Use this when you know your input\ncontains just the commit message itself (and not an email or the output of git\nformat-patch).\n", "long": "--no-divider" } ] }, "CONFIGURATION VARIABLES": { "content": "trailer.separators\nThis option tells which characters are recognized as trailer separators. By default only\n: is recognized as a trailer separator, except that = is always accepted on the command\nline for compatibility with other git commands.\n\nThe first character given by this option will be the default character used when another\nseparator is not specified in the config for this trailer.\n\nFor example, if the value for this option is \"%=$\", then only lines using the format\n with containing %, = or $ and then spaces will be considered\ntrailers. And % will be the default separator used, so by default trailers will appear\nlike: % (one percent sign and one space will appear between the key and the\nvalue).\n\ntrailer.where\nThis option tells where a new trailer will be added.\n\nThis can be end, which is the default, start, after or before.\n\nIf it is end, then each new trailer will appear at the end of the existing trailers.\n\nIf it is start, then each new trailer will appear at the start, instead of the end, of\nthe existing trailers.\n\nIf it is after, then each new trailer will appear just after the last trailer with the\nsame .\n\nIf it is before, then each new trailer will appear just before the first trailer with the\nsame .\n\ntrailer.ifexists\nThis option makes it possible to choose what action will be performed when there is\nalready at least one trailer with the same in the input.\n\nThe valid values for this option are: addIfDifferentNeighbor (this is the default),\naddIfDifferent, add, replace or doNothing.\n\nWith addIfDifferentNeighbor, a new trailer will be added only if no trailer with the same\n(, ) pair is above or below the line where the new trailer will be added.\n\nWith addIfDifferent, a new trailer will be added only if no trailer with the same (,\n) pair is already in the input.\n\nWith add, a new trailer will be added, even if some trailers with the same (,\n) pair are already in the input.\n\nWith replace, an existing trailer with the same will be deleted and the new trailer\nwill be added. The deleted trailer will be the closest one (with the same ) to the\nplace where the new one will be added.\n\nWith doNothing, nothing will be done; that is no new trailer will be added if there is\nalready one with the same in the input.\n\ntrailer.ifmissing\nThis option makes it possible to choose what action will be performed when there is not\nyet any trailer with the same in the input.\n\nThe valid values for this option are: add (this is the default) and doNothing.\n\nWith add, a new trailer will be added.\n\nWith doNothing, nothing will be done.\n\ntrailer..key\nDefines a for the . The must be a prefix (case does not\nmatter) of the . For example, in git config trailer.ack.key \"Acked-by\" the\n\"Acked-by\" is the and the \"ack\" is the . This configuration allows the\nshorter --trailer \"ack:...\" invocation on the command line using the \"ack\" \ninstead of the longer --trailer \"Acked-by:...\".\n\nAt the end of the , a separator can appear and then some space characters. By\ndefault the only valid separator is :, but this can be changed using the\ntrailer.separators config variable.\n\nIf there is a separator in the key, then it overrides the default separator when adding\nthe trailer.\n\ntrailer..where\nThis option takes the same values as the trailer.where configuration variable and it\noverrides what is specified by that option for trailers with the specified .\n\ntrailer..ifexists\nThis option takes the same values as the trailer.ifexists configuration variable and it\noverrides what is specified by that option for trailers with the specified .\n\ntrailer..ifmissing\nThis option takes the same values as the trailer.ifmissing configuration variable and it\noverrides what is specified by that option for trailers with the specified .\n\ntrailer..command\nDeprecated in favor of trailer..cmd. This option behaves in the same way as\ntrailer..cmd, except that it doesn’t pass anything as argument to the specified\ncommand. Instead the first occurrence of substring $ARG is replaced by the that\nwould be passed as argument.\n\nNote that $ARG in the user’s command is only replaced once and that the original way of\nreplacing $ARG is not safe.\n\nWhen both trailer..cmd and trailer..command are given for the same\n, trailer..cmd is used and trailer..command is ignored.\n\ntrailer..cmd\nThis option can be used to specify a shell command that will be called once to\nautomatically add a trailer with the specified , and then called each time a\n--trailer = argument is specified to modify the of the trailer\nthat this option would produce.\n\nWhen the specified command is first called to add a trailer with the specified\n, the behavior is as if a special --trailer = argument was\nadded at the beginning of the \"git interpret-trailers\" command, where is taken to\nbe the standard output of the command with any leading and trailing whitespace trimmed\noff.\n\nIf some --trailer = arguments are also passed on the command line, the\ncommand is called again once for each of these arguments with the same . And\nthe part of these arguments, if any, will be passed to the command as its first\nargument. This way the command can produce a computed from the passed in\nthe --trailer = argument.\n", "subsections": [] }, "EXAMPLES": { "content": "• Configure a sign trailer with a Signed-off-by key, and then add two of these trailers to\na commit message file:\n\n$ git config trailer.sign.key \"Signed-off-by\"\n$ cat msg.txt\nsubject\n\nbody text\n$ git interpret-trailers --trailer 'sign: Alice ' --trailer 'sign: Bob ' \nSigned-off-by: Bob \n\n\n• Use the --in-place option to edit a commit message file in place:\n\n$ cat msg.txt\nsubject\n\nbody text\n\nSigned-off-by: Bob \n$ git interpret-trailers --trailer 'Acked-by: Alice ' --in-place msg.txt\n$ cat msg.txt\nsubject\n\nbody text\n\nSigned-off-by: Bob \nAcked-by: Alice \n\n\n• Extract the last commit as a patch, and add a Cc and a Reviewed-by trailer to it:\n\n$ git format-patch -1\n0001-foo.patch\n$ git interpret-trailers --trailer 'Cc: Alice ' --trailer 'Reviewed-by: Bob ' 0001-foo.patch >0001-bar.patch\n\n\n• Configure a sign trailer with a command to automatically add a 'Signed-off-by: ' with the\nauthor information only if there is no 'Signed-off-by: ' already, and show how it works:\n\n$ cat msg1.txt\nsubject\n\nbody text\n$ git config trailer.sign.key \"Signed-off-by: \"\n$ git config trailer.sign.ifmissing add\n$ git config trailer.sign.ifexists doNothing\n$ git config trailer.sign.cmd 'echo \"$(git config user.name) <$(git config user.email)>\"'\n$ git interpret-trailers --trailer sign \n$ cat msg2.txt\nsubject\n\nbody text\n\nSigned-off-by: Alice \n$ git interpret-trailers --trailer sign \n\n\n• Configure a fix trailer with a key that contains a # and no space after this character,\nand show how it works:\n\n$ git config trailer.separators \":#\"\n$ git config trailer.fix.key \"Fix #\"\n$ echo \"subject\" | git interpret-trailers --trailer fix=42\nsubject\n\nFix #42\n\n\n• Configure a help trailer with a cmd use a script glog-find-author which search specified\nauthor identity from git log in git repository and show how it works:\n\n$ cat ~/bin/glog-find-author\n#!/bin/sh\ntest -n \"$1\" && git log --author=\"$1\" --pretty=\"%an <%ae>\" -1 || true\n$ cat msg.txt\nsubject\n\nbody text\n$ git config trailer.help.key \"Helped-by: \"\n$ git config trailer.help.ifExists \"addIfDifferentNeighbor\"\n$ git config trailer.help.cmd \"~/bin/glog-find-author\"\n$ git interpret-trailers --trailer=\"help:Junio\" --trailer=\"help:Couder\" \nHelped-by: Christian Couder \n\n\n• Configure a ref trailer with a cmd use a script glog-grep to grep last relevant commit\nfrom git log in the git repository and show how it works:\n\n$ cat ~/bin/glog-grep\n#!/bin/sh\ntest -n \"$1\" && git log --grep \"$1\" --pretty=reference -1 || true\n$ cat msg.txt\nsubject\n\nbody text\n$ git config trailer.ref.key \"Reference-to: \"\n$ git config trailer.ref.ifExists \"replace\"\n$ git config trailer.ref.cmd \"~/bin/glog-grep\"\n$ git interpret-trailers --trailer=\"ref:Add copyright notices.\" committemplate.txt\n$ git config commit.template committemplate.txt\n$ cat .git/hooks/commit-msg\n#!/bin/sh\ngit interpret-trailers --trim-empty --trailer \"git-version: \\$(git describe)\" \"\\$1\" > \"\\$1.new\"\nmv \"\\$1.new\" \"\\$1\"\n$ chmod +x .git/hooks/commit-msg\n\n", "subsections": [] }, "SEE ALSO": { "content": "git-commit(1), git-format-patch(1), git-config(1)\n", "subsections": [] }, "GIT": { "content": "Part of the git(1) suite\n\nGit 2.43.0 07/02/2025 GIT-INTERPRET-TRAILERS(1)", "subsections": [] } }, "summary": "git-interpret-trailers - Add or parse structured information in commit messages", "flags": [ { "flag": "", "long": "--in-place", "arg": null, "description": "Edit the files in place." }, { "flag": "", "long": "--trim-empty", "arg": null, "description": "If the part of any trailer contains only whitespace, the whole trailer will be removed from the output. This applies to existing trailers as well as new trailers. --trailer [(=|:)] Specify a (, ) pair that should be applied as a trailer to the inputs. See the description of this command." }, { "flag": "", "long": "--no-where", "arg": "", "description": "Specify where all new trailers will be added. A setting provided with --where overrides the trailer.where and any applicable trailer..where configuration variables and applies to all --trailer options until the next occurrence of --where or --no-where. Upon encountering --no-where, clear the effect of any previous use of --where, such that the relevant configuration variables are no longer overridden. Possible placements are after, before, end or start." }, { "flag": "", "long": "--no-if-exists", "arg": "", "description": "Specify what action will be performed when there is already at least one trailer with the same in the input. A setting provided with --if-exists overrides the trailer.ifExists and any applicable trailer..ifExists configuration variables and applies to all --trailer options until the next occurrence of --if-exists or --no-if-exists. Upon encountering '--no-if-exists, clear the effect of any previous use of '--if-exists, such that the relevant configuration variables are no longer overridden. Possible actions are addIfDifferent, addIfDifferentNeighbor, add, replace and doNothing." }, { "flag": "", "long": "--no-if-missing", "arg": "", "description": "Specify what action will be performed when there is no other trailer with the same in the input. A setting provided with --if-missing overrides the trailer.ifMissing and any applicable trailer..ifMissing configuration variables and applies to all --trailer options until the next occurrence of --if-missing or --no-if-missing. Upon encountering '--no-if-missing, clear the effect of any previous use of '--if-missing, such that the relevant configuration variables are no longer overridden. Possible actions are doNothing or add." }, { "flag": "", "long": "--only-trailers", "arg": null, "description": "Output only the trailers, not any other parts of the input." }, { "flag": "", "long": "--only-input", "arg": null, "description": "Output only trailers that exist in the input; do not add any from the command-line or by applying trailer.* configuration variables." }, { "flag": "", "long": "--unfold", "arg": null, "description": "If a trailer has a value that runs over multiple lines (aka \"folded\"), reformat the value into a single line." }, { "flag": "", "long": "--parse", "arg": null, "description": "A convenience alias for --only-trailers --only-input --unfold. This makes it easier to only see the trailers coming from the input without influencing them with any command line options or configuration variables, while also making the output machine-friendly with --unfold." }, { "flag": "", "long": "--no-divider", "arg": null, "description": "Do not treat --- as the end of the commit message. Use this when you know your input contains just the commit message itself (and not an email or the output of git format-patch)." } ], "examples": [ "• Configure a sign trailer with a Signed-off-by key, and then add two of these trailers to", "a commit message file:", "$ git config trailer.sign.key \"Signed-off-by\"", "$ cat msg.txt", "subject", "body text", "$ git interpret-trailers --trailer 'sign: Alice ' --trailer 'sign: Bob ' ", "Signed-off-by: Bob ", "• Use the --in-place option to edit a commit message file in place:", "$ cat msg.txt", "subject", "body text", "Signed-off-by: Bob ", "$ git interpret-trailers --trailer 'Acked-by: Alice ' --in-place msg.txt", "$ cat msg.txt", "subject", "body text", "Signed-off-by: Bob ", "Acked-by: Alice ", "• 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 ' --trailer 'Reviewed-by: Bob ' 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:", "$ 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 ", "$ cat msg2.txt", "subject", "body text", "Signed-off-by: Alice ", "$ git interpret-trailers --trailer sign ", "• 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 help trailer with a cmd use a script glog-find-author which search specified", "author identity from git log in git repository and show how it works:", "$ 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\" ", "Helped-by: Christian Couder ", "• Configure a ref trailer with a cmd use a script glog-grep to grep last relevant commit", "from git log in the git repository and show how it works:", "$ 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.\" committemplate.txt", "$ git config commit.template committemplate.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": [ { "name": "git-commit", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/git-commit/1/json" }, { "name": "git-format-patch", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/git-format-patch/1/json" }, { "name": "git-config", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/git-config/1/json" } ], "tldr": { "source": "not_found", "examples": [] } }