doc: add documentation for the proc-receive hook

[git] / Documentation / git-for-each-ref.txt

git-for-each-ref(1)
===================

NAME
----
git-for-each-ref - Output information on each ref

SYNOPSIS
--------
[verse]
'git for-each-ref' [--count=<count>] [--shell|--perl|--python|--tcl]
                   [(--sort=<key>)...] [--format=<format>] [<pattern>...]
                   [--points-at=<object>]
                   (--merged[=<object>] | --no-merged[=<object>])
                   [--contains[=<object>]] [--no-contains[=<object>]]

DESCRIPTION
-----------

Iterate over all refs that match `<pattern>` and show them
according to the given `<format>`, after sorting them according
to the given set of `<key>`.  If `<count>` is given, stop after
showing that many refs.  The interpolated values in `<format>`
can optionally be quoted as string literals in the specified
host language allowing their direct evaluation in that language.

OPTIONS
-------
<pattern>...::
        If one or more patterns are given, only refs are shown that
        match against at least one pattern, either using fnmatch(3) or
        literally, in the latter case matching completely or from the
        beginning up to a slash.

--count=<count>::
        By default the command shows all refs that match
        `<pattern>`.  This option makes it stop after showing
        that many refs.

--sort=<key>::
        A field name to sort on.  Prefix `-` to sort in
        descending order of the value.  When unspecified,
        `refname` is used.  You may use the --sort=<key> option
        multiple times, in which case the last key becomes the primary
        key.

--format=<format>::
        A string that interpolates `%(fieldname)` from a ref being shown
        and the object it points at.  If `fieldname`
        is prefixed with an asterisk (`*`) and the ref points
        at a tag object, use the value for the field in the object
        which the tag object refers to (instead of the field in the tag object).
        When unspecified, `<format>` defaults to
        `%(objectname) SPC %(objecttype) TAB %(refname)`.
        It also interpolates `%%` to `%`, and `%xx` where `xx`
        are hex digits interpolates to character with hex code
        `xx`; for example `%00` interpolates to `\0` (NUL),
        `%09` to `\t` (TAB) and `%0a` to `\n` (LF).

--color[=<when>]::
        Respect any colors specified in the `--format` option. The
        `<when>` field must be one of `always`, `never`, or `auto` (if
        `<when>` is absent, behave as if `always` was given).

--shell::
--perl::
--python::
--tcl::
        If given, strings that substitute `%(fieldname)`
        placeholders are quoted as string literals suitable for
        the specified host language.  This is meant to produce
        a scriptlet that can directly be `eval`ed.

--points-at=<object>::
        Only list refs which points at the given object.

--merged[=<object>]::
        Only list refs whose tips are reachable from the
        specified commit (HEAD if not specified),
        incompatible with `--no-merged`.

--no-merged[=<object>]::
        Only list refs whose tips are not reachable from the
        specified commit (HEAD if not specified),
        incompatible with `--merged`.

--contains[=<object>]::
        Only list refs which contain the specified commit (HEAD if not
        specified).

--no-contains[=<object>]::
        Only list refs which don't contain the specified commit (HEAD
        if not specified).

--ignore-case::
        Sorting and filtering refs are case insensitive.

FIELD NAMES
-----------

Various values from structured fields in referenced objects can
be used to interpolate into the resulting output, or as sort
keys.

For all objects, the following names can be used:

refname::
        The name of the ref (the part after $GIT_DIR/).
        For a non-ambiguous short name of the ref append `:short`.
        The option core.warnAmbiguousRefs is used to select the strict
        abbreviation mode. If `lstrip=<N>` (`rstrip=<N>`) is appended, strips `<N>`
        slash-separated path components from the front (back) of the refname
        (e.g. `%(refname:lstrip=2)` turns `refs/tags/foo` into `foo` and
        `%(refname:rstrip=2)` turns `refs/tags/foo` into `refs`).
        If `<N>` is a negative number, strip as many path components as
        necessary from the specified end to leave `-<N>` path components
        (e.g. `%(refname:lstrip=-2)` turns
        `refs/tags/foo` into `tags/foo` and `%(refname:rstrip=-1)`
        turns `refs/tags/foo` into `refs`). When the ref does not have
        enough components, the result becomes an empty string if
        stripping with positive <N>, or it becomes the full refname if
        stripping with negative <N>.  Neither is an error.
+
`strip` can be used as a synonym to `lstrip`.

objecttype::
        The type of the object (`blob`, `tree`, `commit`, `tag`).

objectsize::
        The size of the object (the same as 'git cat-file -s' reports).
        Append `:disk` to get the size, in bytes, that the object takes up on
        disk. See the note about on-disk sizes in the `CAVEATS` section below.
objectname::
        The object name (aka SHA-1).
        For a non-ambiguous abbreviation of the object name append `:short`.
        For an abbreviation of the object name with desired length append
        `:short=<length>`, where the minimum length is MINIMUM_ABBREV. The
        length may be exceeded to ensure unique object names.
deltabase::
        This expands to the object name of the delta base for the
        given object, if it is stored as a delta.  Otherwise it
        expands to the null object name (all zeroes).

upstream::
        The name of a local ref which can be considered ``upstream''
        from the displayed ref. Respects `:short`, `:lstrip` and
        `:rstrip` in the same way as `refname` above.  Additionally
        respects `:track` to show "[ahead N, behind M]" and
        `:trackshort` to show the terse version: ">" (ahead), "<"
        (behind), "<>" (ahead and behind), or "=" (in sync). `:track`
        also prints "[gone]" whenever unknown upstream ref is
        encountered. Append `:track,nobracket` to show tracking
        information without brackets (i.e "ahead N, behind M").
+
For any remote-tracking branch `%(upstream)`, `%(upstream:remotename)`
and `%(upstream:remoteref)` refer to the name of the remote and the
name of the tracked remote ref, respectively. In other words, the
remote-tracking branch can be updated explicitly and individually by
using the refspec `%(upstream:remoteref):%(upstream)` to fetch from
`%(upstream:remotename)`.
+
Has no effect if the ref does not have tracking information associated
with it.  All the options apart from `nobracket` are mutually exclusive,
but if used together the last option is selected.

push::
        The name of a local ref which represents the `@{push}`
        location for the displayed ref. Respects `:short`, `:lstrip`,
        `:rstrip`, `:track`, `:trackshort`, `:remotename`, and `:remoteref`
        options as `upstream` does. Produces an empty string if no `@{push}`
        ref is configured.

HEAD::
        '*' if HEAD matches current ref (the checked out branch), ' '
        otherwise.

color::
        Change output color. Followed by `:<colorname>`, where color
        names are described under Values in the "CONFIGURATION FILE"
        section of linkgit:git-config[1].  For example,
        `%(color:bold red)`.

align::
        Left-, middle-, or right-align the content between
        %(align:...) and %(end). The "align:" is followed by
        `width=<width>` and `position=<position>` in any order
        separated by a comma, where the `<position>` is either left,
        right or middle, default being left and `<width>` is the total
        length of the content with alignment. For brevity, the
        "width=" and/or "position=" prefixes may be omitted, and bare
        <width> and <position> used instead.  For instance,
        `%(align:<width>,<position>)`. If the contents length is more
        than the width then no alignment is performed. If used with
        `--quote` everything in between %(align:...) and %(end) is
        quoted, but if nested then only the topmost level performs
        quoting.

if::
        Used as %(if)...%(then)...%(end) or
        %(if)...%(then)...%(else)...%(end).  If there is an atom with
        value or string literal after the %(if) then everything after
        the %(then) is printed, else if the %(else) atom is used, then
        everything after %(else) is printed. We ignore space when
        evaluating the string before %(then), this is useful when we
        use the %(HEAD) atom which prints either "*" or " " and we
        want to apply the 'if' condition only on the 'HEAD' ref.
        Append ":equals=<string>" or ":notequals=<string>" to compare
        the value between the %(if:...) and %(then) atoms with the
        given string.

symref::
        The ref which the given symbolic ref refers to. If not a
        symbolic ref, nothing is printed. Respects the `:short`,
        `:lstrip` and `:rstrip` options in the same way as `refname`
        above.

worktreepath::
        The absolute path to the worktree in which the ref is checked
        out, if it is checked out in any linked worktree. Empty string
        otherwise.

In addition to the above, for commit and tag objects, the header
field names (`tree`, `parent`, `object`, `type`, and `tag`) can
be used to specify the value in the header field.

For commit and tag objects, the special `creatordate` and `creator`
fields will correspond to the appropriate date or name-email-date tuple
from the `committer` or `tagger` fields depending on the object type.
These are intended for working on a mix of annotated and lightweight tags.

Fields that have name-email-date tuple as its value (`author`,
`committer`, and `tagger`) can be suffixed with `name`, `email`,
and `date` to extract the named component.

The complete message in a commit and tag object is `contents`.
Its first line is `contents:subject`, where subject is the concatenation
of all lines of the commit message up to the first blank line.  The next
line is `contents:body`, where body is all of the lines after the first
blank line.  The optional GPG signature is `contents:signature`.  The
first `N` lines of the message is obtained using `contents:lines=N`.
Additionally, the trailers as interpreted by linkgit:git-interpret-trailers[1]
are obtained as `trailers` (or by using the historical alias
`contents:trailers`).  Non-trailer lines from the trailer block can be omitted
with `trailers:only`. Whitespace-continuations can be removed from trailers so
that each trailer appears on a line by itself with its full content with
`trailers:unfold`. Both can be used together as `trailers:unfold,only`.

For sorting purposes, fields with numeric values sort in numeric order
(`objectsize`, `authordate`, `committerdate`, `creatordate`, `taggerdate`).
All other fields are used to sort in their byte-value order.

There is also an option to sort by versions, this can be done by using
the fieldname `version:refname` or its alias `v:refname`.

In any case, a field name that refers to a field inapplicable to
the object referred by the ref does not cause an error.  It
returns an empty string instead.

As a special case for the date-type fields, you may specify a format for
the date by adding `:` followed by date format name (see the
values the `--date` option to linkgit:git-rev-list[1] takes).

Some atoms like %(align) and %(if) always require a matching %(end).
We call them "opening atoms" and sometimes denote them as %($open).

When a scripting language specific quoting is in effect, everything
between a top-level opening atom and its matching %(end) is evaluated
according to the semantics of the opening atom and only its result
from the top-level is quoted.


EXAMPLES
--------

An example directly producing formatted text.  Show the most recent
3 tagged commits:

------------
#!/bin/sh

git for-each-ref --count=3 --sort='-*authordate' \
--format='From: %(*authorname) %(*authoremail)
Subject: %(*subject)
Date: %(*authordate)
Ref: %(*refname)

%(*body)
' 'refs/tags'
------------


A simple example showing the use of shell eval on the output,
demonstrating the use of --shell.  List the prefixes of all heads:
------------
#!/bin/sh

git for-each-ref --shell --format="ref=%(refname)" refs/heads | \
while read entry
do
        eval "$entry"
        echo `dirname $ref`
done
------------


A bit more elaborate report on tags, demonstrating that the format
may be an entire script:
------------
#!/bin/sh

fmt='
        r=%(refname)
        t=%(*objecttype)
        T=${r#refs/tags/}

        o=%(*objectname)
        n=%(*authorname)
        e=%(*authoremail)
        s=%(*subject)
        d=%(*authordate)
        b=%(*body)

        kind=Tag
        if test "z$t" = z
        then
                # could be a lightweight tag
                t=%(objecttype)
                kind="Lightweight tag"
                o=%(objectname)
                n=%(authorname)
                e=%(authoremail)
                s=%(subject)
                d=%(authordate)
                b=%(body)
        fi
        echo "$kind $T points at a $t object $o"
        if test "z$t" = zcommit
        then
                echo "The commit was authored by $n $e
at $d, and titled

    $s

Its message reads as:
"
                echo "$b" | sed -e "s/^/    /"
                echo
        fi
'

eval=`git for-each-ref --shell --format="$fmt" \
        --sort='*objecttype' \
        --sort=-taggerdate \
        refs/tags`
eval "$eval"
------------


An example to show the usage of %(if)...%(then)...%(else)...%(end).
This prefixes the current branch with a star.

------------
git for-each-ref --format="%(if)%(HEAD)%(then)* %(else)  %(end)%(refname:short)" refs/heads/
------------


An example to show the usage of %(if)...%(then)...%(end).
This prints the authorname, if present.

------------
git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Authored by: %(authorname)%(end)"
------------

CAVEATS
-------

Note that the sizes of objects on disk are reported accurately, but care
should be taken in drawing conclusions about which refs or objects are
responsible for disk usage. The size of a packed non-delta object may be
much larger than the size of objects which delta against it, but the
choice of which object is the base and which is the delta is arbitrary
and is subject to change during a repack.

Note also that multiple copies of an object may be present in the object
database; in this case, it is undefined which copy's size or delta base
will be reported.

SEE ALSO
--------
linkgit:git-show-ref[1]

GIT
---
Part of the linkgit:git[1] suite