Documentation / git-rev-parse.txton commit Merge branch 'sb/cd-then-git-can-be-written-as-git-c' (e11c826)
   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' [ --option ] <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--not::
 130        When showing object names, prefix them with '{caret}' and
 131        strip '{caret}' prefix from the object names that already have
 132        one.
 133
 134--abbrev-ref[=(strict|loose)]::
 135        A non-ambiguous short name of the objects name.
 136        The option core.warnAmbiguousRefs is used to select the strict
 137        abbreviation mode.
 138
 139--short::
 140--short=number::
 141        Instead of outputting the full SHA-1 values of object names try to
 142        abbreviate them to a shorter unique name. When no length is specified
 143        7 is used. The minimum length is 4.
 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 `$GIT_DIR` is not defined and the current directory
 217is not detected to lie in a Git repository or work tree
 218print a message to stderr and exit with nonzero status.
 219
 220--git-common-dir::
 221        Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
 222
 223--is-inside-git-dir::
 224        When the current working directory is below the repository
 225        directory print "true", otherwise "false".
 226
 227--is-inside-work-tree::
 228        When the current working directory is inside the work tree of the
 229        repository print "true", otherwise "false".
 230
 231--is-bare-repository::
 232        When the repository is bare print "true", otherwise "false".
 233
 234--resolve-git-dir <path>::
 235        Check if <path> is a valid repository or a gitfile that
 236        points at a valid repository, and print the location of the
 237        repository.  If <path> is a gitfile then the resolved path
 238        to the real repository is printed.
 239
 240--git-path <path>::
 241        Resolve "$GIT_DIR/<path>" and takes other path relocation
 242        variables such as $GIT_OBJECT_DIRECTORY,
 243        $GIT_INDEX_FILE... into account. For example, if
 244        $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
 245        --git-path objects/abc" returns /foo/bar/abc.
 246
 247--show-cdup::
 248        When the command is invoked from a subdirectory, show the
 249        path of the top-level directory relative to the current
 250        directory (typically a sequence of "../", or an empty string).
 251
 252--show-prefix::
 253        When the command is invoked from a subdirectory, show the
 254        path of the current directory relative to the top-level
 255        directory.
 256
 257--show-toplevel::
 258        Show the absolute path of the top-level directory.
 259
 260--shared-index-path::
 261        Show the path to the shared index file in split index mode, or
 262        empty if not in split-index mode.
 263
 264Other Options
 265~~~~~~~~~~~~~
 266
 267--since=datestring::
 268--after=datestring::
 269        Parse the date string, and output the corresponding
 270        --max-age= parameter for 'git rev-list'.
 271
 272--until=datestring::
 273--before=datestring::
 274        Parse the date string, and output the corresponding
 275        --min-age= parameter for 'git rev-list'.
 276
 277<args>...::
 278        Flags and parameters to be parsed.
 279
 280
 281include::revisions.txt[]
 282
 283PARSEOPT
 284--------
 285
 286In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 287scripts the same facilities C builtins have. It works as an option normalizer
 288(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 289
 290It takes on the standard input the specification of the options to parse and
 291understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 292to replace the arguments with normalized ones.  In case of error, it outputs
 293usage on the standard error stream, and exits with code 129.
 294
 295Note: Make sure you quote the result when passing it to `eval`.  See
 296below for an example.
 297
 298Input Format
 299~~~~~~~~~~~~
 300
 301'git rev-parse --parseopt' input format is fully text based. It has two parts,
 302separated by a line that contains only `--`. The lines before the separator
 303(should be one or more) are used for the usage.
 304The lines after the separator describe the options.
 305
 306Each line of options has this format:
 307
 308------------
 309<opt-spec><flags>*<arg-hint>? SP+ help LF
 310------------
 311
 312`<opt-spec>`::
 313        its format is the short option character, then the long option name
 314        separated by a comma. Both parts are not required, though at least one
 315        is necessary. May not contain any of the `<flags>` characters.
 316        `h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`.
 317
 318`<flags>`::
 319        `<flags>` are of `*`, `=`, `?` or `!`.
 320        * Use `=` if the option takes an argument.
 321
 322        * Use `?` to mean that the option takes an optional argument. You
 323          probably want to use the `--stuck-long` mode to be able to
 324          unambiguously parse the optional argument.
 325
 326        * Use `*` to mean that this option should not be listed in the usage
 327          generated for the `-h` argument. It's shown for `--help-all` as
 328          documented in linkgit:gitcli[7].
 329
 330        * Use `!` to not make the corresponding negated long option available.
 331
 332`<arg-hint>`::
 333        `<arg-hint>`, if specified, is used as a name of the argument in the
 334        help output, for options that take arguments. `<arg-hint>` is
 335        terminated by the first whitespace.  It is customary to use a
 336        dash to separate words in a multi-word argument hint.
 337
 338The remainder of the line, after stripping the spaces, is used
 339as the help associated to the option.
 340
 341Blank lines are ignored, and lines that don't match this specification are used
 342as option group headers (start the line with a space to create such
 343lines on purpose).
 344
 345Example
 346~~~~~~~
 347
 348------------
 349OPTS_SPEC="\
 350some-command [options] <args>...
 351
 352some-command does foo and bar!
 353--
 354h,help    show the help
 355
 356foo       some nifty option --foo
 357bar=      some cool option --bar with an argument
 358baz=arg   another cool option --baz with a named argument
 359qux?path  qux may take a path argument but has meaning by itself
 360
 361  An option group Header
 362C?        option C with an optional argument"
 363
 364eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 365------------
 366
 367
 368Usage text
 369~~~~~~~~~~
 370
 371When `"$@"` is `-h` or `--help` in the above example, the following
 372usage text would be shown:
 373
 374------------
 375usage: some-command [options] <args>...
 376
 377    some-command does foo and bar!
 378
 379    -h, --help            show the help
 380    --foo                 some nifty option --foo
 381    --bar ...             some cool option --bar with an argument
 382    --baz <arg>           another cool option --baz with a named argument
 383    --qux[=<path>]        qux may take a path argument but has meaning by itself
 384
 385An option group Header
 386    -C[...]               option C with an optional argument
 387------------
 388
 389SQ-QUOTE
 390--------
 391
 392In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 393single line suitable for `sh(1)` `eval`. This line is made by
 394normalizing the arguments following `--sq-quote`. Nothing other than
 395quoting the arguments is done.
 396
 397If you want command input to still be interpreted as usual by
 398'git rev-parse' before the output is shell quoted, see the `--sq`
 399option.
 400
 401Example
 402~~~~~~~
 403
 404------------
 405$ cat >your-git-script.sh <<\EOF
 406#!/bin/sh
 407args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 408command="git frotz -n24 $args"          # and use it inside a handcrafted
 409                                        # command line
 410eval "$command"
 411EOF
 412
 413$ sh your-git-script.sh "a b'c"
 414------------
 415
 416EXAMPLES
 417--------
 418
 419* Print the object name of the current commit:
 420+
 421------------
 422$ git rev-parse --verify HEAD
 423------------
 424
 425* Print the commit object name from the revision in the $REV shell variable:
 426+
 427------------
 428$ git rev-parse --verify $REV^{commit}
 429------------
 430+
 431This will error out if $REV is empty or not a valid revision.
 432
 433* Similar to above:
 434+
 435------------
 436$ git rev-parse --default master --verify $REV
 437------------
 438+
 439but if $REV is empty, the commit object name from master will be printed.
 440
 441GIT
 442---
 443Part of the linkgit:git[1] suite