Documentation / git-rev-parse.txton commit Merge branch 'jk/sha1-file-reduce-useless-warnings' (cedeffe)
   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 `$GIT_DIR` is not defined and the current directory
 216is not detected to lie in a Git repository or work tree
 217print a message to stderr and exit with nonzero status.
 218
 219--git-common-dir::
 220        Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
 221
 222--is-inside-git-dir::
 223        When the current working directory is below the repository
 224        directory print "true", otherwise "false".
 225
 226--is-inside-work-tree::
 227        When the current working directory is inside the work tree of the
 228        repository print "true", otherwise "false".
 229
 230--is-bare-repository::
 231        When the repository is bare print "true", otherwise "false".
 232
 233--resolve-git-dir <path>::
 234        Check if <path> is a valid repository or a gitfile that
 235        points at a valid repository, and print the location of the
 236        repository.  If <path> is a gitfile then the resolved path
 237        to the real repository is printed.
 238
 239--git-path <path>::
 240        Resolve "$GIT_DIR/<path>" and takes other path relocation
 241        variables such as $GIT_OBJECT_DIRECTORY,
 242        $GIT_INDEX_FILE... into account. For example, if
 243        $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
 244        --git-path objects/abc" returns /foo/bar/abc.
 245
 246--show-cdup::
 247        When the command is invoked from a subdirectory, show the
 248        path of the top-level directory relative to the current
 249        directory (typically a sequence of "../", or an empty string).
 250
 251--show-prefix::
 252        When the command is invoked from a subdirectory, show the
 253        path of the current directory relative to the top-level
 254        directory.
 255
 256--show-toplevel::
 257        Show the absolute path of the top-level directory.
 258
 259--shared-index-path::
 260        Show the path to the shared index file in split index mode, or
 261        empty if not in split-index mode.
 262
 263Other Options
 264~~~~~~~~~~~~~
 265
 266--since=datestring::
 267--after=datestring::
 268        Parse the date string, and output the corresponding
 269        --max-age= parameter for 'git rev-list'.
 270
 271--until=datestring::
 272--before=datestring::
 273        Parse the date string, and output the corresponding
 274        --min-age= parameter for 'git rev-list'.
 275
 276<args>...::
 277        Flags and parameters to be parsed.
 278
 279
 280include::revisions.txt[]
 281
 282PARSEOPT
 283--------
 284
 285In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 286scripts the same facilities C builtins have. It works as an option normalizer
 287(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 288
 289It takes on the standard input the specification of the options to parse and
 290understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 291to replace the arguments with normalized ones.  In case of error, it outputs
 292usage on the standard error stream, and exits with code 129.
 293
 294Note: Make sure you quote the result when passing it to `eval`.  See
 295below for an example.
 296
 297Input Format
 298~~~~~~~~~~~~
 299
 300'git rev-parse --parseopt' input format is fully text based. It has two parts,
 301separated by a line that contains only `--`. The lines before the separator
 302(should be one or more) are used for the usage.
 303The lines after the separator describe the options.
 304
 305Each line of options has this format:
 306
 307------------
 308<opt-spec><flags>*<arg-hint>? SP+ help LF
 309------------
 310
 311`<opt-spec>`::
 312        its format is the short option character, then the long option name
 313        separated by a comma. Both parts are not required, though at least one
 314        is necessary. `h,help`, `dry-run` and `f` are all three correct
 315        `<opt-spec>`.
 316
 317`<flags>`::
 318        `<flags>` are of `*`, `=`, `?` or `!`.
 319        * Use `=` if the option takes an argument.
 320
 321        * Use `?` to mean that the option takes an optional argument. You
 322          probably want to use the `--stuck-long` mode to be able to
 323          unambiguously parse the optional argument.
 324
 325        * Use `*` to mean that this option should not be listed in the usage
 326          generated for the `-h` argument. It's shown for `--help-all` as
 327          documented in linkgit:gitcli[7].
 328
 329        * Use `!` to not make the corresponding negated long option available.
 330
 331`<arg-hint>`::
 332        `<arg-hint>`, if specified, is used as a name of the argument in the
 333        help output, for options that take arguments. `<arg-hint>` is
 334        terminated by the first whitespace.  It is customary to use a
 335        dash to separate words in a multi-word argument hint.
 336
 337The remainder of the line, after stripping the spaces, is used
 338as the help associated to the option.
 339
 340Blank lines are ignored, and lines that don't match this specification are used
 341as option group headers (start the line with a space to create such
 342lines on purpose).
 343
 344Example
 345~~~~~~~
 346
 347------------
 348OPTS_SPEC="\
 349some-command [options] <args>...
 350
 351some-command does foo and bar!
 352--
 353h,help    show the help
 354
 355foo       some nifty option --foo
 356bar=      some cool option --bar with an argument
 357baz=arg   another cool option --baz with a named argument
 358qux?path  qux may take a path argument but has meaning by itself
 359
 360  An option group Header
 361C?        option C with an optional argument"
 362
 363eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 364------------
 365
 366
 367Usage text
 368~~~~~~~~~~
 369
 370When `"$@"` is `-h` or `--help` in the above example, the following
 371usage text would be shown:
 372
 373------------
 374usage: some-command [options] <args>...
 375
 376    some-command does foo and bar!
 377
 378    -h, --help            show the help
 379    --foo                 some nifty option --foo
 380    --bar ...             some cool option --bar with an argument
 381    --baz <arg>           another cool option --baz with a named argument
 382    --qux[=<path>]        qux may take a path argument but has meaning by itself
 383
 384An option group Header
 385    -C[...]               option C with an optional argument
 386------------
 387
 388SQ-QUOTE
 389--------
 390
 391In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 392single line suitable for `sh(1)` `eval`. This line is made by
 393normalizing the arguments following `--sq-quote`. Nothing other than
 394quoting the arguments is done.
 395
 396If you want command input to still be interpreted as usual by
 397'git rev-parse' before the output is shell quoted, see the `--sq`
 398option.
 399
 400Example
 401~~~~~~~
 402
 403------------
 404$ cat >your-git-script.sh <<\EOF
 405#!/bin/sh
 406args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 407command="git frotz -n24 $args"          # and use it inside a handcrafted
 408                                        # command line
 409eval "$command"
 410EOF
 411
 412$ sh your-git-script.sh "a b'c"
 413------------
 414
 415EXAMPLES
 416--------
 417
 418* Print the object name of the current commit:
 419+
 420------------
 421$ git rev-parse --verify HEAD
 422------------
 423
 424* Print the commit object name from the revision in the $REV shell variable:
 425+
 426------------
 427$ git rev-parse --verify $REV^{commit}
 428------------
 429+
 430This will error out if $REV is empty or not a valid revision.
 431
 432* Similar to above:
 433+
 434------------
 435$ git rev-parse --default master --verify $REV
 436------------
 437+
 438but if $REV is empty, the commit object name from master will be printed.
 439
 440GIT
 441---
 442Part of the linkgit:git[1] suite