Documentation / git-rev-parse.txton commit CodingGuidelines: Add a section on writing documentation (c455bd8)
   1git-rev-parse(1)
   2================
   3
   4NAME
   5----
   6git-rev-parse - Pick out and massage parameters
   7
   8
   9SYNOPSIS
  10--------
  11'git rev-parse' [ --option ] <args>...
  12
  13DESCRIPTION
  14-----------
  15
  16Many git porcelainish commands take mixture of flags
  17(i.e. parameters that begin with a dash '-') and parameters
  18meant for the underlying 'git rev-list' command they use internally
  19and flags and parameters for the other commands they use
  20downstream of 'git rev-list'.  This command is used to
  21distinguish between them.
  22
  23
  24OPTIONS
  25-------
  26--parseopt::
  27        Use 'git rev-parse' in option parsing mode (see PARSEOPT section below).
  28
  29--keep-dashdash::
  30        Only meaningful in `--parseopt` mode. Tells the option parser to echo
  31        out the first `--` met instead of skipping it.
  32
  33--stop-at-non-option::
  34        Only meaningful in `--parseopt` mode.  Lets the option parser stop at
  35        the first non-option argument.  This can be used to parse sub-commands
  36        that take options themselves.
  37
  38--sq-quote::
  39        Use 'git rev-parse' in shell quoting mode (see SQ-QUOTE
  40        section below). In contrast to the `--sq` option below, this
  41        mode does only quoting. Nothing else is done to command input.
  42
  43--revs-only::
  44        Do not output flags and parameters not meant for
  45        'git rev-list' command.
  46
  47--no-revs::
  48        Do not output flags and parameters meant for
  49        'git rev-list' command.
  50
  51--flags::
  52        Do not output non-flag parameters.
  53
  54--no-flags::
  55        Do not output flag parameters.
  56
  57--default <arg>::
  58        If there is no parameter given by the user, use `<arg>`
  59        instead.
  60
  61--verify::
  62        The parameter given must be usable as a single, valid
  63        object name.  Otherwise barf and abort.
  64
  65-q::
  66--quiet::
  67        Only meaningful in `--verify` mode. Do not output an error
  68        message if the first argument is not a valid object name;
  69        instead exit with non-zero status silently.
  70
  71--sq::
  72        Usually the output is made one line per flag and
  73        parameter.  This option makes output a single line,
  74        properly quoted for consumption by shell.  Useful when
  75        you expect your parameter to contain whitespaces and
  76        newlines (e.g. when using pickaxe `-S` with
  77        'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
  78        the command input is still interpreted as usual.
  79
  80--not::
  81        When showing object names, prefix them with '{caret}' and
  82        strip '{caret}' prefix from the object names that already have
  83        one.
  84
  85--symbolic::
  86        Usually the object names are output in SHA1 form (with
  87        possible '{caret}' prefix); this option makes them output in a
  88        form as close to the original input as possible.
  89
  90--symbolic-full-name::
  91        This is similar to \--symbolic, but it omits input that
  92        are not refs (i.e. branch or tag names; or more
  93        explicitly disambiguating "heads/master" form, when you
  94        want to name the "master" branch when there is an
  95        unfortunately named tag "master"), and show them as full
  96        refnames (e.g. "refs/heads/master").
  97
  98--abbrev-ref[=(strict|loose)]::
  99        A non-ambiguous short name of the objects name.
 100        The option core.warnAmbiguousRefs is used to select the strict
 101        abbreviation mode.
 102
 103--all::
 104        Show all refs found in `refs/`.
 105
 106--branches[=pattern]::
 107--tags[=pattern]::
 108--remotes[=pattern]::
 109        Show all branches, tags, or remote-tracking branches,
 110        respectively (i.e., refs found in `refs/heads`,
 111        `refs/tags`, or `refs/remotes`, respectively).
 112+
 113If a `pattern` is given, only refs matching the given shell glob are
 114shown.  If the pattern does not contain a globbing character (`?`,
 115`{asterisk}`, or `[`), it is turned into a prefix match by
 116appending `/{asterisk}`.
 117
 118--glob=pattern::
 119        Show all refs matching the shell glob pattern `pattern`. If
 120        the pattern does not start with `refs/`, this is automatically
 121        prepended.  If the pattern does not contain a globbing
 122        character (`?`, `{asterisk}`, or `[`), it is turned into a prefix
 123        match by appending `/{asterisk}`.
 124
 125--show-toplevel::
 126        Show the absolute path of the top-level directory.
 127
 128--show-prefix::
 129        When the command is invoked from a subdirectory, show the
 130        path of the current directory relative to the top-level
 131        directory.
 132
 133--show-cdup::
 134        When the command is invoked from a subdirectory, show the
 135        path of the top-level directory relative to the current
 136        directory (typically a sequence of "../", or an empty string).
 137
 138--git-dir::
 139        Show `$GIT_DIR` if defined else show the path to the .git directory.
 140
 141--is-inside-git-dir::
 142        When the current working directory is below the repository
 143        directory print "true", otherwise "false".
 144
 145--is-inside-work-tree::
 146        When the current working directory is inside the work tree of the
 147        repository print "true", otherwise "false".
 148
 149--is-bare-repository::
 150        When the repository is bare print "true", otherwise "false".
 151
 152--local-env-vars::
 153        List the GIT_* environment variables that are local to the
 154        repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
 155        Only the names of the variables are listed, not their value,
 156        even if they are set.
 157
 158--short::
 159--short=number::
 160        Instead of outputting the full SHA1 values of object names try to
 161        abbreviate them to a shorter unique name. When no length is specified
 162        7 is used. The minimum length is 4.
 163
 164--since=datestring::
 165--after=datestring::
 166        Parse the date string, and output the corresponding
 167        --max-age= parameter for 'git rev-list'.
 168
 169--until=datestring::
 170--before=datestring::
 171        Parse the date string, and output the corresponding
 172        --min-age= parameter for 'git rev-list'.
 173
 174<args>...::
 175        Flags and parameters to be parsed.
 176
 177
 178include::revisions.txt[]
 179
 180PARSEOPT
 181--------
 182
 183In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 184scripts the same facilities C builtins have. It works as an option normalizer
 185(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 186
 187It takes on the standard input the specification of the options to parse and
 188understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 189to replace the arguments with normalized ones.  In case of error, it outputs
 190usage on the standard error stream, and exits with code 129.
 191
 192Note: Make sure you quote the result when passing it to `eval`.  See
 193below for an example.
 194
 195Input Format
 196~~~~~~~~~~~~
 197
 198'git rev-parse --parseopt' input format is fully text based. It has two parts,
 199separated by a line that contains only `--`. The lines before the separator
 200(should be more than one) are used for the usage.
 201The lines after the separator describe the options.
 202
 203Each line of options has this format:
 204
 205------------
 206<opt_spec><flags>* SP+ help LF
 207------------
 208
 209`<opt_spec>`::
 210        its format is the short option character, then the long option name
 211        separated by a comma. Both parts are not required, though at least one
 212        is necessary. `h,help`, `dry-run` and `f` are all three correct
 213        `<opt_spec>`.
 214
 215`<flags>`::
 216        `<flags>` are of `*`, `=`, `?` or `!`.
 217        * Use `=` if the option takes an argument.
 218
 219        * Use `?` to mean that the option is optional (though its use is discouraged).
 220
 221        * Use `*` to mean that this option should not be listed in the usage
 222          generated for the `-h` argument. It's shown for `--help-all` as
 223          documented in linkgit:gitcli[7].
 224
 225        * Use `!` to not make the corresponding negated long option available.
 226
 227The remainder of the line, after stripping the spaces, is used
 228as the help associated to the option.
 229
 230Blank lines are ignored, and lines that don't match this specification are used
 231as option group headers (start the line with a space to create such
 232lines on purpose).
 233
 234Example
 235~~~~~~~
 236
 237------------
 238OPTS_SPEC="\
 239some-command [options] <args>...
 240
 241some-command does foo and bar!
 242--
 243h,help    show the help
 244
 245foo       some nifty option --foo
 246bar=      some cool option --bar with an argument
 247
 248  An option group Header
 249C?        option C with an optional argument"
 250
 251eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 252------------
 253
 254SQ-QUOTE
 255--------
 256
 257In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 258single line suitable for `sh(1)` `eval`. This line is made by
 259normalizing the arguments following `--sq-quote`. Nothing other than
 260quoting the arguments is done.
 261
 262If you want command input to still be interpreted as usual by
 263'git rev-parse' before the output is shell quoted, see the `--sq`
 264option.
 265
 266Example
 267~~~~~~~
 268
 269------------
 270$ cat >your-git-script.sh <<\EOF
 271#!/bin/sh
 272args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 273command="git frotz -n24 $args"          # and use it inside a handcrafted
 274                                        # command line
 275eval "$command"
 276EOF
 277
 278$ sh your-git-script.sh "a b'c"
 279------------
 280
 281EXAMPLES
 282--------
 283
 284* Print the object name of the current commit:
 285+
 286------------
 287$ git rev-parse --verify HEAD
 288------------
 289
 290* Print the commit object name from the revision in the $REV shell variable:
 291+
 292------------
 293$ git rev-parse --verify $REV
 294------------
 295+
 296This will error out if $REV is empty or not a valid revision.
 297
 298* Same as above:
 299+
 300------------
 301$ git rev-parse --default master --verify $REV
 302------------
 303+
 304but if $REV is empty, the commit object name from master will be printed.
 305
 306
 307Author
 308------
 309Written by Linus Torvalds <torvalds@osdl.org> .
 310Junio C Hamano <gitster@pobox.com> and Pierre Habouzit <madcoder@debian.org>
 311
 312Documentation
 313--------------
 314Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
 315
 316GIT
 317---
 318Part of the linkgit:git[1] suite