Documentation/git-rev-parse.txt

   1 git-rev-parse(1)
   2 ================
   3
   4 NAME
   5 ----
   6 git-rev-parse - Pick out and massage parameters
   7
   8
   9 SYNOPSIS
  10 --------
  11 [verse]
  12 'git rev-parse' [ --option ] <args>...
  13
  14 DESCRIPTION
  15 -----------
  16
  17 Many Git porcelainish commands take mixture of flags
  18 (i.e. parameters that begin with a dash '-') and parameters
  19 meant for the underlying 'git rev-list' command they use internally
  20 and flags and parameters for the other commands they use
  21 downstream of 'git rev-list'.  This command is used to
  22 distinguish between them.
  23
  24
  25 OPTIONS
  26 -------
  27
  28 Operation Modes
  29 ~~~~~~~~~~~~~~~
  30
  31 Each 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
  41 Options 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
  57 Options 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
  74 Options 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 +
  87 This can be used to convert arguments to a command run in a subdirectory
  88 so that they can still be used after moving to the top-level of the
  89 repository.  For example:
  90 +
  91 ----
  92 prefix=$(git rev-parse --show-prefix)
  93 cd "$(git rev-parse --show-toplevel)"
  94 eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
  95 ----
  96
  97 --verify::
  98         Verify that exactly one parameter is provided, and that it
  99         can be turned into a raw 20-byte SHA-1 that can be used to
 100         access the object database. If so, emit it to the standard
 101         output; otherwise, error out.
 102 +
 103 If you want to make sure that the output actually names an object in
 104 your object database and/or can be used as a specific type of object
 105 you require, you can add "\^{type}" peeling operator to the parameter.
 106 For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
 107 names an existing object that is a commit-ish (i.e. a commit, or an
 108 annotated tag that points at a commit).  To make sure that `$VAR`
 109 names an existing object of any type, `git rev-parse "$VAR^{object}"`
 110 can 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
 157 Options 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 +
 170 If a `pattern` is given, only refs matching the given shell glob are
 171 shown.  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 +
 189 The patterns given should not begin with `refs/heads`, `refs/tags`, or
 190 `refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
 191 respectively, and they must begin with `refs/` when applied to `--glob`
 192 or `--all`. If a trailing '/{asterisk}' is intended, it must be given
 193 explicitly.
 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
 201 Options 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 +
 215 If `$GIT_DIR` is not defined and the current directory
 216 is not detected to lie in a Git repository or work tree
 217 print a message to stderr and exit with nonzero status.
 218
 219 --is-inside-git-dir::
 220         When the current working directory is below the repository
 221         directory print "true", otherwise "false".
 222
 223 --is-inside-work-tree::
 224         When the current working directory is inside the work tree of the
 225         repository print "true", otherwise "false".
 226
 227 --is-bare-repository::
 228         When the repository is bare print "true", otherwise "false".
 229
 230 --resolve-git-dir <path>::
 231         Check if <path> is a valid repository or a gitfile that
 232         points at a valid repository, and print the location of the
 233         repository.  If <path> is a gitfile then the resolved path
 234         to the real repository is printed.
 235
 236 --git-path <path>::
 237         Resolve "$GIT_DIR/<path>" and takes other path relocation
 238         variables such as $GIT_OBJECT_DIRECTORY,
 239         $GIT_INDEX_FILE... into account. For example, if
 240         $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
 241         --git-path objects/abc" returns /foo/bar/abc.
 242
 243 --show-cdup::
 244         When the command is invoked from a subdirectory, show the
 245         path of the top-level directory relative to the current
 246         directory (typically a sequence of "../", or an empty string).
 247
 248 --show-prefix::
 249         When the command is invoked from a subdirectory, show the
 250         path of the current directory relative to the top-level
 251         directory.
 252
 253 --show-toplevel::
 254         Show the absolute path of the top-level directory.
 255
 256 --shared-index-path::
 257         Show the path to the shared index file in split index mode, or
 258         empty if not in split-index mode.
 259
 260 Other Options
 261 ~~~~~~~~~~~~~
 262
 263 --since=datestring::
 264 --after=datestring::
 265         Parse the date string, and output the corresponding
 266         --max-age= parameter for 'git rev-list'.
 267
 268 --until=datestring::
 269 --before=datestring::
 270         Parse the date string, and output the corresponding
 271         --min-age= parameter for 'git rev-list'.
 272
 273 <args>...::
 274         Flags and parameters to be parsed.
 275
 276
 277 include::revisions.txt[]
 278
 279 PARSEOPT
 280 --------
 281
 282 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 283 scripts the same facilities C builtins have. It works as an option normalizer
 284 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 285
 286 It takes on the standard input the specification of the options to parse and
 287 understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 288 to replace the arguments with normalized ones.  In case of error, it outputs
 289 usage on the standard error stream, and exits with code 129.
 290
 291 Note: Make sure you quote the result when passing it to `eval`.  See
 292 below for an example.
 293
 294 Input Format
 295 ~~~~~~~~~~~~
 296
 297 'git rev-parse --parseopt' input format is fully text based. It has two parts,
 298 separated by a line that contains only `--`. The lines before the separator
 299 (should be one or more) are used for the usage.
 300 The lines after the separator describe the options.
 301
 302 Each line of options has this format:
 303
 304 ------------
 305 <opt-spec><flags>*<arg-hint>? SP+ help LF
 306 ------------
 307
 308 `<opt-spec>`::
 309         its format is the short option character, then the long option name
 310         separated by a comma. Both parts are not required, though at least one
 311         is necessary. `h,help`, `dry-run` and `f` are all three correct
 312         `<opt-spec>`.
 313
 314 `<flags>`::
 315         `<flags>` are of `*`, `=`, `?` or `!`.
 316         * Use `=` if the option takes an argument.
 317
 318         * Use `?` to mean that the option takes an optional argument. You
 319           probably want to use the `--stuck-long` mode to be able to
 320           unambiguously parse the optional argument.
 321
 322         * Use `*` to mean that this option should not be listed in the usage
 323           generated for the `-h` argument. It's shown for `--help-all` as
 324           documented in linkgit:gitcli[7].
 325
 326         * Use `!` to not make the corresponding negated long option available.
 327
 328 `<arg-hint>`::
 329         `<arg-hint>`, if specified, is used as a name of the argument in the
 330         help output, for options that take arguments. `<arg-hint>` is
 331         terminated by the first whitespace.  It is customary to use a
 332         dash to separate words in a multi-word argument hint.
 333
 334 The remainder of the line, after stripping the spaces, is used
 335 as the help associated to the option.
 336
 337 Blank lines are ignored, and lines that don't match this specification are used
 338 as option group headers (start the line with a space to create such
 339 lines on purpose).
 340
 341 Example
 342 ~~~~~~~
 343
 344 ------------
 345 OPTS_SPEC="\
 346 some-command [options] <args>...
 347
 348 some-command does foo and bar!
 349 --
 350 h,help    show the help
 351
 352 foo       some nifty option --foo
 353 bar=      some cool option --bar with an argument
 354 baz=arg   another cool option --baz with a named argument
 355 qux?path  qux may take a path argument but has meaning by itself
 356
 357   An option group Header
 358 C?        option C with an optional argument"
 359
 360 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 361 ------------
 362
 363
 364 Usage text
 365 ~~~~~~~~~~
 366
 367 When `"$@"` is `-h` or `--help` in the above example, the following
 368 usage text would be shown:
 369
 370 ------------
 371 usage: some-command [options] <args>...
 372
 373     some-command does foo and bar!
 374
 375     -h, --help            show the help
 376     --foo                 some nifty option --foo
 377     --bar ...             some cool option --bar with an argument
 378     --baz <arg>           another cool option --baz with a named argument
 379     --qux[=<path>]        qux may take a path argument but has meaning by itself
 380
 381 An option group Header
 382     -C[...]               option C with an optional argument
 383 ------------
 384
 385 SQ-QUOTE
 386 --------
 387
 388 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 389 single line suitable for `sh(1)` `eval`. This line is made by
 390 normalizing the arguments following `--sq-quote`. Nothing other than
 391 quoting the arguments is done.
 392
 393 If you want command input to still be interpreted as usual by
 394 'git rev-parse' before the output is shell quoted, see the `--sq`
 395 option.
 396
 397 Example
 398 ~~~~~~~
 399
 400 ------------
 401 $ cat >your-git-script.sh <<\EOF
 402 #!/bin/sh
 403 args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 404 command="git frotz -n24 $args"          # and use it inside a handcrafted
 405                                         # command line
 406 eval "$command"
 407 EOF
 408
 409 $ sh your-git-script.sh "a b'c"
 410 ------------
 411
 412 EXAMPLES
 413 --------
 414
 415 * Print the object name of the current commit:
 416 +
 417 ------------
 418 $ git rev-parse --verify HEAD
 419 ------------
 420
 421 * Print the commit object name from the revision in the $REV shell variable:
 422 +
 423 ------------
 424 $ git rev-parse --verify $REV^{commit}
 425 ------------
 426 +
 427 This will error out if $REV is empty or not a valid revision.
 428
 429 * Similar to above:
 430 +
 431 ------------
 432 $ git rev-parse --default master --verify $REV
 433 ------------
 434 +
 435 but if $REV is empty, the commit object name from master will be printed.
 436
 437 GIT
 438 ---
 439 Part of the linkgit:git[1] suite