Documentation / git-rev-parse.txton commit credential: let helpers tell us to quit (59b3865)
   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
 118--sq::
 119        Usually the output is made one line per flag and
 120        parameter.  This option makes output a single line,
 121        properly quoted for consumption by shell.  Useful when
 122        you expect your parameter to contain whitespaces and
 123        newlines (e.g. when using pickaxe `-S` with
 124        'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
 125        the command input is still interpreted as usual.
 126
 127--not::
 128        When showing object names, prefix them with '{caret}' and
 129        strip '{caret}' prefix from the object names that already have
 130        one.
 131
 132--abbrev-ref[=(strict|loose)]::
 133        A non-ambiguous short name of the objects name.
 134        The option core.warnAmbiguousRefs is used to select the strict
 135        abbreviation mode.
 136
 137--short::
 138--short=number::
 139        Instead of outputting the full SHA-1 values of object names try to
 140        abbreviate them to a shorter unique name. When no length is specified
 141        7 is used. The minimum length is 4.
 142
 143--symbolic::
 144        Usually the object names are output in SHA-1 form (with
 145        possible '{caret}' prefix); this option makes them output in a
 146        form as close to the original input as possible.
 147
 148--symbolic-full-name::
 149        This is similar to \--symbolic, but it omits input that
 150        are not refs (i.e. branch or tag names; or more
 151        explicitly disambiguating "heads/master" form, when you
 152        want to name the "master" branch when there is an
 153        unfortunately named tag "master"), and show them as full
 154        refnames (e.g. "refs/heads/master").
 155
 156Options for Objects
 157~~~~~~~~~~~~~~~~~~~
 158
 159--all::
 160        Show all refs found in `refs/`.
 161
 162--branches[=pattern]::
 163--tags[=pattern]::
 164--remotes[=pattern]::
 165        Show all branches, tags, or remote-tracking branches,
 166        respectively (i.e., refs found in `refs/heads`,
 167        `refs/tags`, or `refs/remotes`, respectively).
 168+
 169If a `pattern` is given, only refs matching the given shell glob are
 170shown.  If the pattern does not contain a globbing character (`?`,
 171`*`, or `[`), it is turned into a prefix match by appending `/*`.
 172
 173--glob=pattern::
 174        Show all refs matching the shell glob pattern `pattern`. If
 175        the pattern does not start with `refs/`, this is automatically
 176        prepended.  If the pattern does not contain a globbing
 177        character (`?`, `*`, or `[`), it is turned into a prefix
 178        match by appending `/*`.
 179
 180--exclude=<glob-pattern>::
 181        Do not include refs matching '<glob-pattern>' that the next `--all`,
 182        `--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
 183        consider. Repetitions of this option accumulate exclusion patterns
 184        up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
 185        `--glob` option (other options or arguments do not clear
 186        accumlated patterns).
 187+
 188The patterns given should not begin with `refs/heads`, `refs/tags`, or
 189`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
 190respectively, and they must begin with `refs/` when applied to `--glob`
 191or `--all`. If a trailing '/{asterisk}' is intended, it must be given
 192explicitly.
 193
 194--disambiguate=<prefix>::
 195        Show every object whose name begins with the given prefix.
 196        The <prefix> must be at least 4 hexadecimal digits long to
 197        avoid listing each and every object in the repository by
 198        mistake.
 199
 200Options for Files
 201~~~~~~~~~~~~~~~~~
 202
 203--local-env-vars::
 204        List the GIT_* environment variables that are local to the
 205        repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
 206        Only the names of the variables are listed, not their value,
 207        even if they are set.
 208
 209--git-dir::
 210        Show `$GIT_DIR` if defined. Otherwise show the path to
 211        the .git directory. The path shown, when relative, is
 212        relative to the current working directory.
 213+
 214If `$GIT_DIR` is not defined and the current directory
 215is not detected to lie in a Git repository or work tree
 216print a message to stderr and exit with nonzero status.
 217
 218--is-inside-git-dir::
 219        When the current working directory is below the repository
 220        directory print "true", otherwise "false".
 221
 222--is-inside-work-tree::
 223        When the current working directory is inside the work tree of the
 224        repository print "true", otherwise "false".
 225
 226--is-bare-repository::
 227        When the repository is bare print "true", otherwise "false".
 228
 229--resolve-git-dir <path>::
 230        Check if <path> is a valid repository or a gitfile that
 231        points at a valid repository, and print the location of the
 232        repository.  If <path> is a gitfile then the resolved path
 233        to the real repository is printed.
 234
 235--show-cdup::
 236        When the command is invoked from a subdirectory, show the
 237        path of the top-level directory relative to the current
 238        directory (typically a sequence of "../", or an empty string).
 239
 240--show-prefix::
 241        When the command is invoked from a subdirectory, show the
 242        path of the current directory relative to the top-level
 243        directory.
 244
 245--show-toplevel::
 246        Show the absolute path of the top-level directory.
 247
 248--shared-index-path::
 249        Show the path to the shared index file in split index mode, or
 250        empty if not in split-index mode.
 251
 252Other Options
 253~~~~~~~~~~~~~
 254
 255--since=datestring::
 256--after=datestring::
 257        Parse the date string, and output the corresponding
 258        --max-age= parameter for 'git rev-list'.
 259
 260--until=datestring::
 261--before=datestring::
 262        Parse the date string, and output the corresponding
 263        --min-age= parameter for 'git rev-list'.
 264
 265<args>...::
 266        Flags and parameters to be parsed.
 267
 268
 269include::revisions.txt[]
 270
 271PARSEOPT
 272--------
 273
 274In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 275scripts the same facilities C builtins have. It works as an option normalizer
 276(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 277
 278It takes on the standard input the specification of the options to parse and
 279understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 280to replace the arguments with normalized ones.  In case of error, it outputs
 281usage on the standard error stream, and exits with code 129.
 282
 283Note: Make sure you quote the result when passing it to `eval`.  See
 284below for an example.
 285
 286Input Format
 287~~~~~~~~~~~~
 288
 289'git rev-parse --parseopt' input format is fully text based. It has two parts,
 290separated by a line that contains only `--`. The lines before the separator
 291(should be one or more) are used for the usage.
 292The lines after the separator describe the options.
 293
 294Each line of options has this format:
 295
 296------------
 297<opt-spec><flags>*<arg-hint>? SP+ help LF
 298------------
 299
 300`<opt-spec>`::
 301        its format is the short option character, then the long option name
 302        separated by a comma. Both parts are not required, though at least one
 303        is necessary. `h,help`, `dry-run` and `f` are all three correct
 304        `<opt-spec>`.
 305
 306`<flags>`::
 307        `<flags>` are of `*`, `=`, `?` or `!`.
 308        * Use `=` if the option takes an argument.
 309
 310        * Use `?` to mean that the option takes an optional argument. You
 311          probably want to use the `--stuck-long` mode to be able to
 312          unambiguously parse the optional argument.
 313
 314        * Use `*` to mean that this option should not be listed in the usage
 315          generated for the `-h` argument. It's shown for `--help-all` as
 316          documented in linkgit:gitcli[7].
 317
 318        * Use `!` to not make the corresponding negated long option available.
 319
 320`<arg-hint>`::
 321        `<arg-hint>`, if specified, is used as a name of the argument in the
 322        help output, for options that take arguments. `<arg-hint>` is
 323        terminated by the first whitespace.  It is customary to use a
 324        dash to separate words in a multi-word argument hint.
 325
 326The remainder of the line, after stripping the spaces, is used
 327as the help associated to the option.
 328
 329Blank lines are ignored, and lines that don't match this specification are used
 330as option group headers (start the line with a space to create such
 331lines on purpose).
 332
 333Example
 334~~~~~~~
 335
 336------------
 337OPTS_SPEC="\
 338some-command [options] <args>...
 339
 340some-command does foo and bar!
 341--
 342h,help    show the help
 343
 344foo       some nifty option --foo
 345bar=      some cool option --bar with an argument
 346baz=arg   another cool option --baz with a named argument
 347qux?path  qux may take a path argument but has meaning by itself
 348
 349  An option group Header
 350C?        option C with an optional argument"
 351
 352eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 353------------
 354
 355
 356Usage text
 357~~~~~~~~~~
 358
 359When `"$@"` is `-h` or `--help` in the above example, the following
 360usage text would be shown:
 361
 362------------
 363usage: some-command [options] <args>...
 364
 365    some-command does foo and bar!
 366
 367    -h, --help            show the help
 368    --foo                 some nifty option --foo
 369    --bar ...             some cool option --bar with an argument
 370    --baz <arg>           another cool option --baz with a named argument
 371    --qux[=<path>]        qux may take a path argument but has meaning by itself
 372
 373An option group Header
 374    -C[...]               option C with an optional argument
 375------------
 376
 377SQ-QUOTE
 378--------
 379
 380In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 381single line suitable for `sh(1)` `eval`. This line is made by
 382normalizing the arguments following `--sq-quote`. Nothing other than
 383quoting the arguments is done.
 384
 385If you want command input to still be interpreted as usual by
 386'git rev-parse' before the output is shell quoted, see the `--sq`
 387option.
 388
 389Example
 390~~~~~~~
 391
 392------------
 393$ cat >your-git-script.sh <<\EOF
 394#!/bin/sh
 395args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 396command="git frotz -n24 $args"          # and use it inside a handcrafted
 397                                        # command line
 398eval "$command"
 399EOF
 400
 401$ sh your-git-script.sh "a b'c"
 402------------
 403
 404EXAMPLES
 405--------
 406
 407* Print the object name of the current commit:
 408+
 409------------
 410$ git rev-parse --verify HEAD
 411------------
 412
 413* Print the commit object name from the revision in the $REV shell variable:
 414+
 415------------
 416$ git rev-parse --verify $REV^{commit}
 417------------
 418+
 419This will error out if $REV is empty or not a valid revision.
 420
 421* Similar to above:
 422+
 423------------
 424$ git rev-parse --default master --verify $REV
 425------------
 426+
 427but if $REV is empty, the commit object name from master will be printed.
 428
 429GIT
 430---
 431Part of the linkgit:git[1] suite