Documentation / git-rev-parse.txton commit read-cache: add post-index-change hook (1956ecd)
   1git-rev-parse(1)
   2================
   3
   4NAME
   5----
   6git-rev-parse - Pick out and massage parameters
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git rev-parse' [<options>] <args>...
  13
  14DESCRIPTION
  15-----------
  16
  17Many Git porcelainish commands take mixture of flags
  18(i.e. parameters that begin with a dash '-') and parameters
  19meant for the underlying 'git rev-list' command they use internally
  20and flags and parameters for the other commands they use
  21downstream of 'git rev-list'.  This command is used to
  22distinguish between them.
  23
  24
  25OPTIONS
  26-------
  27
  28Operation Modes
  29~~~~~~~~~~~~~~~
  30
  31Each of these options must appear first on the command line.
  32
  33--parseopt::
  34        Use 'git rev-parse' in option parsing mode (see PARSEOPT section below).
  35
  36--sq-quote::
  37        Use 'git rev-parse' in shell quoting mode (see SQ-QUOTE
  38        section below). In contrast to the `--sq` option below, this
  39        mode does only quoting. Nothing else is done to command input.
  40
  41Options for --parseopt
  42~~~~~~~~~~~~~~~~~~~~~~
  43
  44--keep-dashdash::
  45        Only meaningful in `--parseopt` mode. Tells the option parser to echo
  46        out the first `--` met instead of skipping it.
  47
  48--stop-at-non-option::
  49        Only meaningful in `--parseopt` mode.  Lets the option parser stop at
  50        the first non-option argument.  This can be used to parse sub-commands
  51        that take options themselves.
  52
  53--stuck-long::
  54        Only meaningful in `--parseopt` mode. Output the options in their
  55        long form if available, and with their arguments stuck.
  56
  57Options for Filtering
  58~~~~~~~~~~~~~~~~~~~~~
  59
  60--revs-only::
  61        Do not output flags and parameters not meant for
  62        'git rev-list' command.
  63
  64--no-revs::
  65        Do not output flags and parameters meant for
  66        'git rev-list' command.
  67
  68--flags::
  69        Do not output non-flag parameters.
  70
  71--no-flags::
  72        Do not output flag parameters.
  73
  74Options for Output
  75~~~~~~~~~~~~~~~~~~
  76
  77--default <arg>::
  78        If there is no parameter given by the user, use `<arg>`
  79        instead.
  80
  81--prefix <arg>::
  82        Behave as if 'git rev-parse' was invoked from the `<arg>`
  83        subdirectory of the working tree.  Any relative filenames are
  84        resolved as if they are prefixed by `<arg>` and will be printed
  85        in that form.
  86+
  87This can be used to convert arguments to a command run in a subdirectory
  88so that they can still be used after moving to the top-level of the
  89repository.  For example:
  90+
  91----
  92prefix=$(git rev-parse --show-prefix)
  93cd "$(git rev-parse --show-toplevel)"
  94# rev-parse provides the -- needed for 'set'
  95eval "set $(git rev-parse --sq --prefix "$prefix" -- "$@")"
  96----
  97
  98--verify::
  99        Verify that exactly one parameter is provided, and that it
 100        can be turned into a raw 20-byte SHA-1 that can be used to
 101        access the object database. If so, emit it to the standard
 102        output; otherwise, error out.
 103+
 104If you want to make sure that the output actually names an object in
 105your object database and/or can be used as a specific type of object
 106you require, you can add the `^{type}` peeling operator to the parameter.
 107For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
 108names an existing object that is a commit-ish (i.e. a commit, or an
 109annotated tag that points at a commit).  To make sure that `$VAR`
 110names an existing object of any type, `git rev-parse "$VAR^{object}"`
 111can be used.
 112
 113-q::
 114--quiet::
 115        Only meaningful in `--verify` mode. Do not output an error
 116        message if the first argument is not a valid object name;
 117        instead exit with non-zero status silently.
 118        SHA-1s for valid object names are printed to stdout on success.
 119
 120--sq::
 121        Usually the output is made one line per flag and
 122        parameter.  This option makes output a single line,
 123        properly quoted for consumption by shell.  Useful when
 124        you expect your parameter to contain whitespaces and
 125        newlines (e.g. when using pickaxe `-S` with
 126        'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
 127        the command input is still interpreted as usual.
 128
 129--short[=length]::
 130        Same as `--verify` but shortens the object name to a unique
 131        prefix with at least `length` characters. The minimum length
 132        is 4, the default is the effective value of the `core.abbrev`
 133        configuration variable (see linkgit:git-config[1]).
 134
 135--not::
 136        When showing object names, prefix them with '{caret}' and
 137        strip '{caret}' prefix from the object names that already have
 138        one.
 139
 140--abbrev-ref[=(strict|loose)]::
 141        A non-ambiguous short name of the objects name.
 142        The option core.warnAmbiguousRefs is used to select the strict
 143        abbreviation mode.
 144
 145--symbolic::
 146        Usually the object names are output in SHA-1 form (with
 147        possible '{caret}' prefix); this option makes them output in a
 148        form as close to the original input as possible.
 149
 150--symbolic-full-name::
 151        This is similar to --symbolic, but it omits input that
 152        are not refs (i.e. branch or tag names; or more
 153        explicitly disambiguating "heads/master" form, when you
 154        want to name the "master" branch when there is an
 155        unfortunately named tag "master"), and show them as full
 156        refnames (e.g. "refs/heads/master").
 157
 158Options for Objects
 159~~~~~~~~~~~~~~~~~~~
 160
 161--all::
 162        Show all refs found in `refs/`.
 163
 164--branches[=pattern]::
 165--tags[=pattern]::
 166--remotes[=pattern]::
 167        Show all branches, tags, or remote-tracking branches,
 168        respectively (i.e., refs found in `refs/heads`,
 169        `refs/tags`, or `refs/remotes`, respectively).
 170+
 171If a `pattern` is given, only refs matching the given shell glob are
 172shown.  If the pattern does not contain a globbing character (`?`,
 173`*`, or `[`), it is turned into a prefix match by appending `/*`.
 174
 175--glob=pattern::
 176        Show all refs matching the shell glob pattern `pattern`. If
 177        the pattern does not start with `refs/`, this is automatically
 178        prepended.  If the pattern does not contain a globbing
 179        character (`?`, `*`, or `[`), it is turned into a prefix
 180        match by appending `/*`.
 181
 182--exclude=<glob-pattern>::
 183        Do not include refs matching '<glob-pattern>' that the next `--all`,
 184        `--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
 185        consider. Repetitions of this option accumulate exclusion patterns
 186        up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
 187        `--glob` option (other options or arguments do not clear
 188        accumulated patterns).
 189+
 190The patterns given should not begin with `refs/heads`, `refs/tags`, or
 191`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
 192respectively, and they must begin with `refs/` when applied to `--glob`
 193or `--all`. If a trailing '/{asterisk}' is intended, it must be given
 194explicitly.
 195
 196--disambiguate=<prefix>::
 197        Show every object whose name begins with the given prefix.
 198        The <prefix> must be at least 4 hexadecimal digits long to
 199        avoid listing each and every object in the repository by
 200        mistake.
 201
 202Options for Files
 203~~~~~~~~~~~~~~~~~
 204
 205--local-env-vars::
 206        List the GIT_* environment variables that are local to the
 207        repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
 208        Only the names of the variables are listed, not their value,
 209        even if they are set.
 210
 211--git-dir::
 212        Show `$GIT_DIR` if defined. Otherwise show the path to
 213        the .git directory. The path shown, when relative, is
 214        relative to the current working directory.
 215+
 216If `$GIT_DIR` is not defined and the current directory
 217is not detected to lie in a Git repository or work tree
 218print a message to stderr and exit with nonzero status.
 219
 220--absolute-git-dir::
 221        Like `--git-dir`, but its output is always the canonicalized
 222        absolute path.
 223
 224--git-common-dir::
 225        Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
 226
 227--is-inside-git-dir::
 228        When the current working directory is below the repository
 229        directory print "true", otherwise "false".
 230
 231--is-inside-work-tree::
 232        When the current working directory is inside the work tree of the
 233        repository print "true", otherwise "false".
 234
 235--is-bare-repository::
 236        When the repository is bare print "true", otherwise "false".
 237
 238--is-shallow-repository::
 239        When the repository is shallow print "true", otherwise "false".
 240
 241--resolve-git-dir <path>::
 242        Check if <path> is a valid repository or a gitfile that
 243        points at a valid repository, and print the location of the
 244        repository.  If <path> is a gitfile then the resolved path
 245        to the real repository is printed.
 246
 247--git-path <path>::
 248        Resolve "$GIT_DIR/<path>" and takes other path relocation
 249        variables such as $GIT_OBJECT_DIRECTORY,
 250        $GIT_INDEX_FILE... into account. For example, if
 251        $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
 252        --git-path objects/abc" returns /foo/bar/abc.
 253
 254--show-cdup::
 255        When the command is invoked from a subdirectory, show the
 256        path of the top-level directory relative to the current
 257        directory (typically a sequence of "../", or an empty string).
 258
 259--show-prefix::
 260        When the command is invoked from a subdirectory, show the
 261        path of the current directory relative to the top-level
 262        directory.
 263
 264--show-toplevel::
 265        Show the absolute path of the top-level directory.
 266
 267--show-superproject-working-tree::
 268        Show the absolute path of the root of the superproject's
 269        working tree (if exists) that uses the current repository as
 270        its submodule.  Outputs nothing if the current repository is
 271        not used as a submodule by any project.
 272
 273--shared-index-path::
 274        Show the path to the shared index file in split index mode, or
 275        empty if not in split-index mode.
 276
 277Other Options
 278~~~~~~~~~~~~~
 279
 280--since=datestring::
 281--after=datestring::
 282        Parse the date string, and output the corresponding
 283        --max-age= parameter for 'git rev-list'.
 284
 285--until=datestring::
 286--before=datestring::
 287        Parse the date string, and output the corresponding
 288        --min-age= parameter for 'git rev-list'.
 289
 290<args>...::
 291        Flags and parameters to be parsed.
 292
 293
 294include::revisions.txt[]
 295
 296PARSEOPT
 297--------
 298
 299In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 300scripts the same facilities C builtins have. It works as an option normalizer
 301(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 302
 303It takes on the standard input the specification of the options to parse and
 304understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 305to replace the arguments with normalized ones.  In case of error, it outputs
 306usage on the standard error stream, and exits with code 129.
 307
 308Note: Make sure you quote the result when passing it to `eval`.  See
 309below for an example.
 310
 311Input Format
 312~~~~~~~~~~~~
 313
 314'git rev-parse --parseopt' input format is fully text based. It has two parts,
 315separated by a line that contains only `--`. The lines before the separator
 316(should be one or more) are used for the usage.
 317The lines after the separator describe the options.
 318
 319Each line of options has this format:
 320
 321------------
 322<opt-spec><flags>*<arg-hint>? SP+ help LF
 323------------
 324
 325`<opt-spec>`::
 326        its format is the short option character, then the long option name
 327        separated by a comma. Both parts are not required, though at least one
 328        is necessary. May not contain any of the `<flags>` characters.
 329        `h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`.
 330
 331`<flags>`::
 332        `<flags>` are of `*`, `=`, `?` or `!`.
 333        * Use `=` if the option takes an argument.
 334
 335        * Use `?` to mean that the option takes an optional argument. You
 336          probably want to use the `--stuck-long` mode to be able to
 337          unambiguously parse the optional argument.
 338
 339        * Use `*` to mean that this option should not be listed in the usage
 340          generated for the `-h` argument. It's shown for `--help-all` as
 341          documented in linkgit:gitcli[7].
 342
 343        * Use `!` to not make the corresponding negated long option available.
 344
 345`<arg-hint>`::
 346        `<arg-hint>`, if specified, is used as a name of the argument in the
 347        help output, for options that take arguments. `<arg-hint>` is
 348        terminated by the first whitespace.  It is customary to use a
 349        dash to separate words in a multi-word argument hint.
 350
 351The remainder of the line, after stripping the spaces, is used
 352as the help associated to the option.
 353
 354Blank lines are ignored, and lines that don't match this specification are used
 355as option group headers (start the line with a space to create such
 356lines on purpose).
 357
 358Example
 359~~~~~~~
 360
 361------------
 362OPTS_SPEC="\
 363some-command [<options>] <args>...
 364
 365some-command does foo and bar!
 366--
 367h,help    show the help
 368
 369foo       some nifty option --foo
 370bar=      some cool option --bar with an argument
 371baz=arg   another cool option --baz with a named argument
 372qux?path  qux may take a path argument but has meaning by itself
 373
 374  An option group Header
 375C?        option C with an optional argument"
 376
 377eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 378------------
 379
 380
 381Usage text
 382~~~~~~~~~~
 383
 384When `"$@"` is `-h` or `--help` in the above example, the following
 385usage text would be shown:
 386
 387------------
 388usage: some-command [<options>] <args>...
 389
 390    some-command does foo and bar!
 391
 392    -h, --help            show the help
 393    --foo                 some nifty option --foo
 394    --bar ...             some cool option --bar with an argument
 395    --baz <arg>           another cool option --baz with a named argument
 396    --qux[=<path>]        qux may take a path argument but has meaning by itself
 397
 398An option group Header
 399    -C[...]               option C with an optional argument
 400------------
 401
 402SQ-QUOTE
 403--------
 404
 405In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 406single line suitable for `sh(1)` `eval`. This line is made by
 407normalizing the arguments following `--sq-quote`. Nothing other than
 408quoting the arguments is done.
 409
 410If you want command input to still be interpreted as usual by
 411'git rev-parse' before the output is shell quoted, see the `--sq`
 412option.
 413
 414Example
 415~~~~~~~
 416
 417------------
 418$ cat >your-git-script.sh <<\EOF
 419#!/bin/sh
 420args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 421command="git frotz -n24 $args"          # and use it inside a handcrafted
 422                                        # command line
 423eval "$command"
 424EOF
 425
 426$ sh your-git-script.sh "a b'c"
 427------------
 428
 429EXAMPLES
 430--------
 431
 432* Print the object name of the current commit:
 433+
 434------------
 435$ git rev-parse --verify HEAD
 436------------
 437
 438* Print the commit object name from the revision in the $REV shell variable:
 439+
 440------------
 441$ git rev-parse --verify $REV^{commit}
 442------------
 443+
 444This will error out if $REV is empty or not a valid revision.
 445
 446* Similar to above:
 447+
 448------------
 449$ git rev-parse --default master --verify $REV
 450------------
 451+
 452but if $REV is empty, the commit object name from master will be printed.
 453
 454GIT
 455---
 456Part of the linkgit:git[1] suite