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 --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
 253 Other 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
 270 include::revisions.txt[]
 271
 272 PARSEOPT
 273 --------
 274
 275 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 276 scripts 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
 279 It takes on the standard input the specification of the options to parse and
 280 understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 281 to replace the arguments with normalized ones.  In case of error, it outputs
 282 usage on the standard error stream, and exits with code 129.
 283
 284 Note: Make sure you quote the result when passing it to `eval`.  See
 285 below for an example.
 286
 287 Input Format
 288 ~~~~~~~~~~~~
 289
 290 'git rev-parse --parseopt' input format is fully text based. It has two parts,
 291 separated by a line that contains only `--`. The lines before the separator
 292 (should be one or more) are used for the usage.
 293 The lines after the separator describe the options.
 294
 295 Each 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
 327 The remainder of the line, after stripping the spaces, is used
 328 as the help associated to the option.
 329
 330 Blank lines are ignored, and lines that don't match this specification are used
 331 as option group headers (start the line with a space to create such
 332 lines on purpose).
 333
 334 Example
 335 ~~~~~~~
 336
 337 ------------
 338 OPTS_SPEC="\
 339 some-command [options] <args>...
 340
 341 some-command does foo and bar!
 342 --
 343 h,help    show the help
 344
 345 foo       some nifty option --foo
 346 bar=      some cool option --bar with an argument
 347 baz=arg   another cool option --baz with a named argument
 348 qux?path  qux may take a path argument but has meaning by itself
 349
 350   An option group Header
 351 C?        option C with an optional argument"
 352
 353 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 354 ------------
 355
 356
 357 Usage text
 358 ~~~~~~~~~~
 359
 360 When `"$@"` is `-h` or `--help` in the above example, the following
 361 usage text would be shown:
 362
 363 ------------
 364 usage: 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
 374 An option group Header
 375     -C[...]               option C with an optional argument
 376 ------------
 377
 378 SQ-QUOTE
 379 --------
 380
 381 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 382 single line suitable for `sh(1)` `eval`. This line is made by
 383 normalizing the arguments following `--sq-quote`. Nothing other than
 384 quoting the arguments is done.
 385
 386 If you want command input to still be interpreted as usual by
 387 'git rev-parse' before the output is shell quoted, see the `--sq`
 388 option.
 389
 390 Example
 391 ~~~~~~~
 392
 393 ------------
 394 $ cat >your-git-script.sh <<\EOF
 395 #!/bin/sh
 396 args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 397 command="git frotz -n24 $args"          # and use it inside a handcrafted
 398                                         # command line
 399 eval "$command"
 400 EOF
 401
 402 $ sh your-git-script.sh "a b'c"
 403 ------------
 404
 405 EXAMPLES
 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 +
 420 This 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 +
 428 but if $REV is empty, the commit object name from master will be printed.
 429
 430 GIT
 431 ---
 432 Part of the linkgit:git[1] suite