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
 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
 156 Options 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 +
 169 If a `pattern` is given, only refs matching the given shell glob are
 170 shown.  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 +
 188 The patterns given should not begin with `refs/heads`, `refs/tags`, or
 189 `refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
 190 respectively, and they must begin with `refs/` when applied to `--glob`
 191 or `--all`. If a trailing '/{asterisk}' is intended, it must be given
 192 explicitly.
 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
 200 Options 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 +
 214 If `$GIT_DIR` is not defined and the current directory
 215 is not detected to lie in a Git repository or work tree
 216 print 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 Other Options
 249 ~~~~~~~~~~~~~
 250
 251 --since=datestring::
 252 --after=datestring::
 253         Parse the date string, and output the corresponding
 254         --max-age= parameter for 'git rev-list'.
 255
 256 --until=datestring::
 257 --before=datestring::
 258         Parse the date string, and output the corresponding
 259         --min-age= parameter for 'git rev-list'.
 260
 261 <args>...::
 262         Flags and parameters to be parsed.
 263
 264
 265 include::revisions.txt[]
 266
 267 PARSEOPT
 268 --------
 269
 270 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 271 scripts the same facilities C builtins have. It works as an option normalizer
 272 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 273
 274 It takes on the standard input the specification of the options to parse and
 275 understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 276 to replace the arguments with normalized ones.  In case of error, it outputs
 277 usage on the standard error stream, and exits with code 129.
 278
 279 Note: Make sure you quote the result when passing it to `eval`.  See
 280 below for an example.
 281
 282 Input Format
 283 ~~~~~~~~~~~~
 284
 285 'git rev-parse --parseopt' input format is fully text based. It has two parts,
 286 separated by a line that contains only `--`. The lines before the separator
 287 (should be more than one) are used for the usage.
 288 The lines after the separator describe the options.
 289
 290 Each line of options has this format:
 291
 292 ------------
 293 <opt_spec><flags>* SP+ help LF
 294 ------------
 295
 296 `<opt_spec>`::
 297         its format is the short option character, then the long option name
 298         separated by a comma. Both parts are not required, though at least one
 299         is necessary. `h,help`, `dry-run` and `f` are all three correct
 300         `<opt_spec>`.
 301
 302 `<flags>`::
 303         `<flags>` are of `*`, `=`, `?` or `!`.
 304         * Use `=` if the option takes an argument.
 305
 306         * Use `?` to mean that the option takes an optional argument. You
 307           probably want to use the `--stuck-long` mode to be able to
 308           unambiguously parse the optional argument.
 309
 310         * Use `*` to mean that this option should not be listed in the usage
 311           generated for the `-h` argument. It's shown for `--help-all` as
 312           documented in linkgit:gitcli[7].
 313
 314         * Use `!` to not make the corresponding negated long option available.
 315
 316 The remainder of the line, after stripping the spaces, is used
 317 as the help associated to the option.
 318
 319 Blank lines are ignored, and lines that don't match this specification are used
 320 as option group headers (start the line with a space to create such
 321 lines on purpose).
 322
 323 Example
 324 ~~~~~~~
 325
 326 ------------
 327 OPTS_SPEC="\
 328 some-command [options] <args>...
 329
 330 some-command does foo and bar!
 331 --
 332 h,help    show the help
 333
 334 foo       some nifty option --foo
 335 bar=      some cool option --bar with an argument
 336
 337   An option group Header
 338 C?        option C with an optional argument"
 339
 340 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 341 ------------
 342
 343 SQ-QUOTE
 344 --------
 345
 346 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 347 single line suitable for `sh(1)` `eval`. This line is made by
 348 normalizing the arguments following `--sq-quote`. Nothing other than
 349 quoting the arguments is done.
 350
 351 If you want command input to still be interpreted as usual by
 352 'git rev-parse' before the output is shell quoted, see the `--sq`
 353 option.
 354
 355 Example
 356 ~~~~~~~
 357
 358 ------------
 359 $ cat >your-git-script.sh <<\EOF
 360 #!/bin/sh
 361 args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 362 command="git frotz -n24 $args"          # and use it inside a handcrafted
 363                                         # command line
 364 eval "$command"
 365 EOF
 366
 367 $ sh your-git-script.sh "a b'c"
 368 ------------
 369
 370 EXAMPLES
 371 --------
 372
 373 * Print the object name of the current commit:
 374 +
 375 ------------
 376 $ git rev-parse --verify HEAD
 377 ------------
 378
 379 * Print the commit object name from the revision in the $REV shell variable:
 380 +
 381 ------------
 382 $ git rev-parse --verify $REV^{commit}
 383 ------------
 384 +
 385 This will error out if $REV is empty or not a valid revision.
 386
 387 * Similar to above:
 388 +
 389 ------------
 390 $ git rev-parse --default master --verify $REV
 391 ------------
 392 +
 393 but if $REV is empty, the commit object name from master will be printed.
 394
 395 GIT
 396 ---
 397 Part of the linkgit:git[1] suite