Documentation / git-rev-parse.txton commit Merge branch 'jk/lock-ref-sha1-basic-return-errors' (3cdb0cb)
   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)"
  94eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
  95----
  96
  97--verify::
  98        Verify that exactly one parameter is provided, and that it
  99        can be turned into a raw 20-byte SHA-1 that can be used to
 100        access the object database. If so, emit it to the standard
 101        output; otherwise, error out.
 102+
 103If you want to make sure that the output actually names an object in
 104your object database and/or can be used as a specific type of object
 105you require, you can add "\^{type}" peeling operator to the parameter.
 106For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
 107names an existing object that is a commit-ish (i.e. a commit, or an
 108annotated tag that points at a commit).  To make sure that `$VAR`
 109names an existing object of any type, `git rev-parse "$VAR^{object}"`
 110can be used.
 111
 112-q::
 113--quiet::
 114        Only meaningful in `--verify` mode. Do not output an error
 115        message if the first argument is not a valid object name;
 116        instead exit with non-zero status silently.
 117        SHA-1s for valid object names are printed to stdout on success.
 118
 119--sq::
 120        Usually the output is made one line per flag and
 121        parameter.  This option makes output a single line,
 122        properly quoted for consumption by shell.  Useful when
 123        you expect your parameter to contain whitespaces and
 124        newlines (e.g. when using pickaxe `-S` with
 125        'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
 126        the command input is still interpreted as usual.
 127
 128--not::
 129        When showing object names, prefix them with '{caret}' and
 130        strip '{caret}' prefix from the object names that already have
 131        one.
 132
 133--abbrev-ref[=(strict|loose)]::
 134        A non-ambiguous short name of the objects name.
 135        The option core.warnAmbiguousRefs is used to select the strict
 136        abbreviation mode.
 137
 138--short::
 139--short=number::
 140        Instead of outputting the full SHA-1 values of object names try to
 141        abbreviate them to a shorter unique name. When no length is specified
 142        7 is used. The minimum length is 4.
 143
 144--symbolic::
 145        Usually the object names are output in SHA-1 form (with
 146        possible '{caret}' prefix); this option makes them output in a
 147        form as close to the original input as possible.
 148
 149--symbolic-full-name::
 150        This is similar to \--symbolic, but it omits input that
 151        are not refs (i.e. branch or tag names; or more
 152        explicitly disambiguating "heads/master" form, when you
 153        want to name the "master" branch when there is an
 154        unfortunately named tag "master"), and show them as full
 155        refnames (e.g. "refs/heads/master").
 156
 157Options for Objects
 158~~~~~~~~~~~~~~~~~~~
 159
 160--all::
 161        Show all refs found in `refs/`.
 162
 163--branches[=pattern]::
 164--tags[=pattern]::
 165--remotes[=pattern]::
 166        Show all branches, tags, or remote-tracking branches,
 167        respectively (i.e., refs found in `refs/heads`,
 168        `refs/tags`, or `refs/remotes`, respectively).
 169+
 170If a `pattern` is given, only refs matching the given shell glob are
 171shown.  If the pattern does not contain a globbing character (`?`,
 172`*`, or `[`), it is turned into a prefix match by appending `/*`.
 173
 174--glob=pattern::
 175        Show all refs matching the shell glob pattern `pattern`. If
 176        the pattern does not start with `refs/`, this is automatically
 177        prepended.  If the pattern does not contain a globbing
 178        character (`?`, `*`, or `[`), it is turned into a prefix
 179        match by appending `/*`.
 180
 181--exclude=<glob-pattern>::
 182        Do not include refs matching '<glob-pattern>' that the next `--all`,
 183        `--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
 184        consider. Repetitions of this option accumulate exclusion patterns
 185        up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
 186        `--glob` option (other options or arguments do not clear
 187        accumulated patterns).
 188+
 189The patterns given should not begin with `refs/heads`, `refs/tags`, or
 190`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
 191respectively, and they must begin with `refs/` when applied to `--glob`
 192or `--all`. If a trailing '/{asterisk}' is intended, it must be given
 193explicitly.
 194
 195--disambiguate=<prefix>::
 196        Show every object whose name begins with the given prefix.
 197        The <prefix> must be at least 4 hexadecimal digits long to
 198        avoid listing each and every object in the repository by
 199        mistake.
 200
 201Options for Files
 202~~~~~~~~~~~~~~~~~
 203
 204--local-env-vars::
 205        List the GIT_* environment variables that are local to the
 206        repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
 207        Only the names of the variables are listed, not their value,
 208        even if they are set.
 209
 210--git-dir::
 211        Show `$GIT_DIR` if defined. Otherwise show the path to
 212        the .git directory. The path shown, when relative, is
 213        relative to the current working directory.
 214+
 215If `$GIT_DIR` is not defined and the current directory
 216is not detected to lie in a Git repository or work tree
 217print a message to stderr and exit with nonzero status.
 218
 219--is-inside-git-dir::
 220        When the current working directory is below the repository
 221        directory print "true", otherwise "false".
 222
 223--is-inside-work-tree::
 224        When the current working directory is inside the work tree of the
 225        repository print "true", otherwise "false".
 226
 227--is-bare-repository::
 228        When the repository is bare print "true", otherwise "false".
 229
 230--resolve-git-dir <path>::
 231        Check if <path> is a valid repository or a gitfile that
 232        points at a valid repository, and print the location of the
 233        repository.  If <path> is a gitfile then the resolved path
 234        to the real repository is printed.
 235
 236--show-cdup::
 237        When the command is invoked from a subdirectory, show the
 238        path of the top-level directory relative to the current
 239        directory (typically a sequence of "../", or an empty string).
 240
 241--show-prefix::
 242        When the command is invoked from a subdirectory, show the
 243        path of the current directory relative to the top-level
 244        directory.
 245
 246--show-toplevel::
 247        Show the absolute path of the top-level directory.
 248
 249--shared-index-path::
 250        Show the path to the shared index file in split index mode, or
 251        empty if not in split-index mode.
 252
 253Other Options
 254~~~~~~~~~~~~~
 255
 256--since=datestring::
 257--after=datestring::
 258        Parse the date string, and output the corresponding
 259        --max-age= parameter for 'git rev-list'.
 260
 261--until=datestring::
 262--before=datestring::
 263        Parse the date string, and output the corresponding
 264        --min-age= parameter for 'git rev-list'.
 265
 266<args>...::
 267        Flags and parameters to be parsed.
 268
 269
 270include::revisions.txt[]
 271
 272PARSEOPT
 273--------
 274
 275In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 276scripts the same facilities C builtins have. It works as an option normalizer
 277(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 278
 279It takes on the standard input the specification of the options to parse and
 280understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 281to replace the arguments with normalized ones.  In case of error, it outputs
 282usage on the standard error stream, and exits with code 129.
 283
 284Note: Make sure you quote the result when passing it to `eval`.  See
 285below for an example.
 286
 287Input Format
 288~~~~~~~~~~~~
 289
 290'git rev-parse --parseopt' input format is fully text based. It has two parts,
 291separated by a line that contains only `--`. The lines before the separator
 292(should be one or more) are used for the usage.
 293The lines after the separator describe the options.
 294
 295Each line of options has this format:
 296
 297------------
 298<opt-spec><flags>*<arg-hint>? SP+ help LF
 299------------
 300
 301`<opt-spec>`::
 302        its format is the short option character, then the long option name
 303        separated by a comma. Both parts are not required, though at least one
 304        is necessary. `h,help`, `dry-run` and `f` are all three correct
 305        `<opt-spec>`.
 306
 307`<flags>`::
 308        `<flags>` are of `*`, `=`, `?` or `!`.
 309        * Use `=` if the option takes an argument.
 310
 311        * Use `?` to mean that the option takes an optional argument. You
 312          probably want to use the `--stuck-long` mode to be able to
 313          unambiguously parse the optional argument.
 314
 315        * Use `*` to mean that this option should not be listed in the usage
 316          generated for the `-h` argument. It's shown for `--help-all` as
 317          documented in linkgit:gitcli[7].
 318
 319        * Use `!` to not make the corresponding negated long option available.
 320
 321`<arg-hint>`::
 322        `<arg-hint>`, if specified, is used as a name of the argument in the
 323        help output, for options that take arguments. `<arg-hint>` is
 324        terminated by the first whitespace.  It is customary to use a
 325        dash to separate words in a multi-word argument hint.
 326
 327The remainder of the line, after stripping the spaces, is used
 328as the help associated to the option.
 329
 330Blank lines are ignored, and lines that don't match this specification are used
 331as option group headers (start the line with a space to create such
 332lines on purpose).
 333
 334Example
 335~~~~~~~
 336
 337------------
 338OPTS_SPEC="\
 339some-command [options] <args>...
 340
 341some-command does foo and bar!
 342--
 343h,help    show the help
 344
 345foo       some nifty option --foo
 346bar=      some cool option --bar with an argument
 347baz=arg   another cool option --baz with a named argument
 348qux?path  qux may take a path argument but has meaning by itself
 349
 350  An option group Header
 351C?        option C with an optional argument"
 352
 353eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 354------------
 355
 356
 357Usage text
 358~~~~~~~~~~
 359
 360When `"$@"` is `-h` or `--help` in the above example, the following
 361usage text would be shown:
 362
 363------------
 364usage: some-command [options] <args>...
 365
 366    some-command does foo and bar!
 367
 368    -h, --help            show the help
 369    --foo                 some nifty option --foo
 370    --bar ...             some cool option --bar with an argument
 371    --baz <arg>           another cool option --baz with a named argument
 372    --qux[=<path>]        qux may take a path argument but has meaning by itself
 373
 374An option group Header
 375    -C[...]               option C with an optional argument
 376------------
 377
 378SQ-QUOTE
 379--------
 380
 381In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 382single line suitable for `sh(1)` `eval`. This line is made by
 383normalizing the arguments following `--sq-quote`. Nothing other than
 384quoting the arguments is done.
 385
 386If you want command input to still be interpreted as usual by
 387'git rev-parse' before the output is shell quoted, see the `--sq`
 388option.
 389
 390Example
 391~~~~~~~
 392
 393------------
 394$ cat >your-git-script.sh <<\EOF
 395#!/bin/sh
 396args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 397command="git frotz -n24 $args"          # and use it inside a handcrafted
 398                                        # command line
 399eval "$command"
 400EOF
 401
 402$ sh your-git-script.sh "a b'c"
 403------------
 404
 405EXAMPLES
 406--------
 407
 408* Print the object name of the current commit:
 409+
 410------------
 411$ git rev-parse --verify HEAD
 412------------
 413
 414* Print the commit object name from the revision in the $REV shell variable:
 415+
 416------------
 417$ git rev-parse --verify $REV^{commit}
 418------------
 419+
 420This will error out if $REV is empty or not a valid revision.
 421
 422* Similar to above:
 423+
 424------------
 425$ git rev-parse --default master --verify $REV
 426------------
 427+
 428but if $REV is empty, the commit object name from master will be printed.
 429
 430GIT
 431---
 432Part of the linkgit:git[1] suite