Documentation / git-rev-parse.txton commit Merge branch 'rs/win32-syslog-leakfix' into next (011eccb)
   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--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 `$GIT_DIR`.
 226
 227--is-inside-git-dir::
 228        When the current working directory is below the repository
 229        directory print "true", otherwise "false".
 230
 231--is-inside-work-tree::
 232        When the current working directory is inside the work tree of the
 233        repository print "true", otherwise "false".
 234
 235--is-bare-repository::
 236        When the repository is bare print "true", otherwise "false".
 237
 238--resolve-git-dir <path>::
 239        Check if <path> is a valid repository or a gitfile that
 240        points at a valid repository, and print the location of the
 241        repository.  If <path> is a gitfile then the resolved path
 242        to the real repository is printed.
 243
 244--git-path <path>::
 245        Resolve "$GIT_DIR/<path>" and takes other path relocation
 246        variables such as $GIT_OBJECT_DIRECTORY,
 247        $GIT_INDEX_FILE... into account. For example, if
 248        $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
 249        --git-path objects/abc" returns /foo/bar/abc.
 250
 251--show-cdup::
 252        When the command is invoked from a subdirectory, show the
 253        path of the top-level directory relative to the current
 254        directory (typically a sequence of "../", or an empty string).
 255
 256--show-prefix::
 257        When the command is invoked from a subdirectory, show the
 258        path of the current directory relative to the top-level
 259        directory.
 260
 261--show-toplevel::
 262        Show the absolute path of the top-level directory.
 263
 264--show-superproject-working-tree
 265        Show the absolute path of the root of the superproject's
 266        working tree (if exists) that uses the current repository as
 267        its submodule.  Outputs nothing if the current repository is
 268        not used as a submodule by any project.
 269
 270--shared-index-path::
 271        Show the path to the shared index file in split index mode, or
 272        empty if not in split-index mode.
 273
 274Other Options
 275~~~~~~~~~~~~~
 276
 277--since=datestring::
 278--after=datestring::
 279        Parse the date string, and output the corresponding
 280        --max-age= parameter for 'git rev-list'.
 281
 282--until=datestring::
 283--before=datestring::
 284        Parse the date string, and output the corresponding
 285        --min-age= parameter for 'git rev-list'.
 286
 287<args>...::
 288        Flags and parameters to be parsed.
 289
 290
 291include::revisions.txt[]
 292
 293PARSEOPT
 294--------
 295
 296In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 297scripts the same facilities C builtins have. It works as an option normalizer
 298(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 299
 300It takes on the standard input the specification of the options to parse and
 301understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 302to replace the arguments with normalized ones.  In case of error, it outputs
 303usage on the standard error stream, and exits with code 129.
 304
 305Note: Make sure you quote the result when passing it to `eval`.  See
 306below for an example.
 307
 308Input Format
 309~~~~~~~~~~~~
 310
 311'git rev-parse --parseopt' input format is fully text based. It has two parts,
 312separated by a line that contains only `--`. The lines before the separator
 313(should be one or more) are used for the usage.
 314The lines after the separator describe the options.
 315
 316Each line of options has this format:
 317
 318------------
 319<opt-spec><flags>*<arg-hint>? SP+ help LF
 320------------
 321
 322`<opt-spec>`::
 323        its format is the short option character, then the long option name
 324        separated by a comma. Both parts are not required, though at least one
 325        is necessary. May not contain any of the `<flags>` characters.
 326        `h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`.
 327
 328`<flags>`::
 329        `<flags>` are of `*`, `=`, `?` or `!`.
 330        * Use `=` if the option takes an argument.
 331
 332        * Use `?` to mean that the option takes an optional argument. You
 333          probably want to use the `--stuck-long` mode to be able to
 334          unambiguously parse the optional argument.
 335
 336        * Use `*` to mean that this option should not be listed in the usage
 337          generated for the `-h` argument. It's shown for `--help-all` as
 338          documented in linkgit:gitcli[7].
 339
 340        * Use `!` to not make the corresponding negated long option available.
 341
 342`<arg-hint>`::
 343        `<arg-hint>`, if specified, is used as a name of the argument in the
 344        help output, for options that take arguments. `<arg-hint>` is
 345        terminated by the first whitespace.  It is customary to use a
 346        dash to separate words in a multi-word argument hint.
 347
 348The remainder of the line, after stripping the spaces, is used
 349as the help associated to the option.
 350
 351Blank lines are ignored, and lines that don't match this specification are used
 352as option group headers (start the line with a space to create such
 353lines on purpose).
 354
 355Example
 356~~~~~~~
 357
 358------------
 359OPTS_SPEC="\
 360some-command [options] <args>...
 361
 362some-command does foo and bar!
 363--
 364h,help    show the help
 365
 366foo       some nifty option --foo
 367bar=      some cool option --bar with an argument
 368baz=arg   another cool option --baz with a named argument
 369qux?path  qux may take a path argument but has meaning by itself
 370
 371  An option group Header
 372C?        option C with an optional argument"
 373
 374eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 375------------
 376
 377
 378Usage text
 379~~~~~~~~~~
 380
 381When `"$@"` is `-h` or `--help` in the above example, the following
 382usage text would be shown:
 383
 384------------
 385usage: some-command [options] <args>...
 386
 387    some-command does foo and bar!
 388
 389    -h, --help            show the help
 390    --foo                 some nifty option --foo
 391    --bar ...             some cool option --bar with an argument
 392    --baz <arg>           another cool option --baz with a named argument
 393    --qux[=<path>]        qux may take a path argument but has meaning by itself
 394
 395An option group Header
 396    -C[...]               option C with an optional argument
 397------------
 398
 399SQ-QUOTE
 400--------
 401
 402In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 403single line suitable for `sh(1)` `eval`. This line is made by
 404normalizing the arguments following `--sq-quote`. Nothing other than
 405quoting the arguments is done.
 406
 407If you want command input to still be interpreted as usual by
 408'git rev-parse' before the output is shell quoted, see the `--sq`
 409option.
 410
 411Example
 412~~~~~~~
 413
 414------------
 415$ cat >your-git-script.sh <<\EOF
 416#!/bin/sh
 417args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 418command="git frotz -n24 $args"          # and use it inside a handcrafted
 419                                        # command line
 420eval "$command"
 421EOF
 422
 423$ sh your-git-script.sh "a b'c"
 424------------
 425
 426EXAMPLES
 427--------
 428
 429* Print the object name of the current commit:
 430+
 431------------
 432$ git rev-parse --verify HEAD
 433------------
 434
 435* Print the commit object name from the revision in the $REV shell variable:
 436+
 437------------
 438$ git rev-parse --verify $REV^{commit}
 439------------
 440+
 441This will error out if $REV is empty or not a valid revision.
 442
 443* Similar to above:
 444+
 445------------
 446$ git rev-parse --default master --verify $REV
 447------------
 448+
 449but if $REV is empty, the commit object name from master will be printed.
 450
 451GIT
 452---
 453Part of the linkgit:git[1] suite