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 Options for Filtering
  54 ~~~~~~~~~~~~~~~~~~~~~
  55
  56 --revs-only::
  57         Do not output flags and parameters not meant for
  58         'git rev-list' command.
  59
  60 --no-revs::
  61         Do not output flags and parameters meant for
  62         'git rev-list' command.
  63
  64 --flags::
  65         Do not output non-flag parameters.
  66
  67 --no-flags::
  68         Do not output flag parameters.
  69
  70 Options for Output
  71 ~~~~~~~~~~~~~~~~~~
  72
  73 --default <arg>::
  74         If there is no parameter given by the user, use `<arg>`
  75         instead.
  76
  77 --prefix <arg>::
  78         Behave as if 'git rev-parse' was invoked from the `<arg>`
  79         subdirectory of the working tree.  Any relative filenames are
  80         resolved as if they are prefixed by `<arg>` and will be printed
  81         in that form.
  82 +
  83 This can be used to convert arguments to a command run in a subdirectory
  84 so that they can still be used after moving to the top-level of the
  85 repository.  For example:
  86 +
  87 ----
  88 prefix=$(git rev-parse --show-prefix)
  89 cd "$(git rev-parse --show-toplevel)"
  90 eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
  91 ----
  92
  93 --verify::
  94         Verify that exactly one parameter is provided, and that it
  95         can be turned into a raw 20-byte SHA-1 that can be used to
  96         access the object database. If so, emit it to the standard
  97         output; otherwise, error out.
  98 +
  99 If you want to make sure that the output actually names an object in
 100 your object database and/or can be used as a specific type of object
 101 you require, you can add "^{type}" peeling operator to the parameter.
 102 For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
 103 names an existing object that is a commit-ish (i.e. a commit, or an
 104 annotated tag that points at a commit).  To make sure that `$VAR`
 105 names an existing object of any type, `git rev-parse "$VAR^{object}"`
 106 can be used.
 107
 108 -q::
 109 --quiet::
 110         Only meaningful in `--verify` mode. Do not output an error
 111         message if the first argument is not a valid object name;
 112         instead exit with non-zero status silently.
 113
 114 --sq::
 115         Usually the output is made one line per flag and
 116         parameter.  This option makes output a single line,
 117         properly quoted for consumption by shell.  Useful when
 118         you expect your parameter to contain whitespaces and
 119         newlines (e.g. when using pickaxe `-S` with
 120         'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
 121         the command input is still interpreted as usual.
 122
 123 --not::
 124         When showing object names, prefix them with '{caret}' and
 125         strip '{caret}' prefix from the object names that already have
 126         one.
 127
 128 --abbrev-ref[=(strict|loose)]::
 129         A non-ambiguous short name of the objects name.
 130         The option core.warnAmbiguousRefs is used to select the strict
 131         abbreviation mode.
 132
 133 --short::
 134 --short=number::
 135         Instead of outputting the full SHA-1 values of object names try to
 136         abbreviate them to a shorter unique name. When no length is specified
 137         7 is used. The minimum length is 4.
 138
 139 --symbolic::
 140         Usually the object names are output in SHA-1 form (with
 141         possible '{caret}' prefix); this option makes them output in a
 142         form as close to the original input as possible.
 143
 144 --symbolic-full-name::
 145         This is similar to \--symbolic, but it omits input that
 146         are not refs (i.e. branch or tag names; or more
 147         explicitly disambiguating "heads/master" form, when you
 148         want to name the "master" branch when there is an
 149         unfortunately named tag "master"), and show them as full
 150         refnames (e.g. "refs/heads/master").
 151
 152 Options for Objects
 153 ~~~~~~~~~~~~~~~~~~~
 154
 155 --all::
 156         Show all refs found in `refs/`.
 157
 158 --branches[=pattern]::
 159 --tags[=pattern]::
 160 --remotes[=pattern]::
 161         Show all branches, tags, or remote-tracking branches,
 162         respectively (i.e., refs found in `refs/heads`,
 163         `refs/tags`, or `refs/remotes`, respectively).
 164 +
 165 If a `pattern` is given, only refs matching the given shell glob are
 166 shown.  If the pattern does not contain a globbing character (`?`,
 167 `*`, or `[`), it is turned into a prefix match by appending `/*`.
 168
 169 --glob=pattern::
 170         Show all refs matching the shell glob pattern `pattern`. If
 171         the pattern does not start with `refs/`, this is automatically
 172         prepended.  If the pattern does not contain a globbing
 173         character (`?`, `*`, or `[`), it is turned into a prefix
 174         match by appending `/*`.
 175
 176 --disambiguate=<prefix>::
 177         Show every object whose name begins with the given prefix.
 178         The <prefix> must be at least 4 hexadecimal digits long to
 179         avoid listing each and every object in the repository by
 180         mistake.
 181
 182 Options for Files
 183 ~~~~~~~~~~~~~~~~~
 184
 185 --local-env-vars::
 186         List the GIT_* environment variables that are local to the
 187         repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
 188         Only the names of the variables are listed, not their value,
 189         even if they are set.
 190
 191 --git-dir::
 192         Show `$GIT_DIR` if defined. Otherwise show the path to
 193         the .git directory. The path shown, when relative, is
 194         relative to the current working directory.
 195 +
 196 If `$GIT_DIR` is not defined and the current directory
 197 is not detected to lie in a Git repository or work tree
 198 print a message to stderr and exit with nonzero status.
 199
 200 --is-inside-git-dir::
 201         When the current working directory is below the repository
 202         directory print "true", otherwise "false".
 203
 204 --is-inside-work-tree::
 205         When the current working directory is inside the work tree of the
 206         repository print "true", otherwise "false".
 207
 208 --is-bare-repository::
 209         When the repository is bare print "true", otherwise "false".
 210
 211 --resolve-git-dir <path>::
 212         Check if <path> is a valid repository or a gitfile that
 213         points at a valid repository, and print the location of the
 214         repository.  If <path> is a gitfile then the resolved path
 215         to the real repository is printed.
 216
 217 --show-cdup::
 218         When the command is invoked from a subdirectory, show the
 219         path of the top-level directory relative to the current
 220         directory (typically a sequence of "../", or an empty string).
 221
 222 --show-prefix::
 223         When the command is invoked from a subdirectory, show the
 224         path of the current directory relative to the top-level
 225         directory.
 226
 227 --show-toplevel::
 228         Show the absolute path of the top-level directory.
 229
 230 Other Options
 231 ~~~~~~~~~~~~~
 232
 233 --since=datestring::
 234 --after=datestring::
 235         Parse the date string, and output the corresponding
 236         --max-age= parameter for 'git rev-list'.
 237
 238 --until=datestring::
 239 --before=datestring::
 240         Parse the date string, and output the corresponding
 241         --min-age= parameter for 'git rev-list'.
 242
 243 <args>...::
 244         Flags and parameters to be parsed.
 245
 246
 247 include::revisions.txt[]
 248
 249 PARSEOPT
 250 --------
 251
 252 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 253 scripts the same facilities C builtins have. It works as an option normalizer
 254 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 255
 256 It takes on the standard input the specification of the options to parse and
 257 understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 258 to replace the arguments with normalized ones.  In case of error, it outputs
 259 usage on the standard error stream, and exits with code 129.
 260
 261 Note: Make sure you quote the result when passing it to `eval`.  See
 262 below for an example.
 263
 264 Input Format
 265 ~~~~~~~~~~~~
 266
 267 'git rev-parse --parseopt' input format is fully text based. It has two parts,
 268 separated by a line that contains only `--`. The lines before the separator
 269 (should be more than one) are used for the usage.
 270 The lines after the separator describe the options.
 271
 272 Each line of options has this format:
 273
 274 ------------
 275 <opt_spec><flags>* SP+ help LF
 276 ------------
 277
 278 `<opt_spec>`::
 279         its format is the short option character, then the long option name
 280         separated by a comma. Both parts are not required, though at least one
 281         is necessary. `h,help`, `dry-run` and `f` are all three correct
 282         `<opt_spec>`.
 283
 284 `<flags>`::
 285         `<flags>` are of `*`, `=`, `?` or `!`.
 286         * Use `=` if the option takes an argument.
 287
 288         * Use `?` to mean that the option is optional (though its use is discouraged).
 289
 290         * Use `*` to mean that this option should not be listed in the usage
 291           generated for the `-h` argument. It's shown for `--help-all` as
 292           documented in linkgit:gitcli[7].
 293
 294         * Use `!` to not make the corresponding negated long option available.
 295
 296 The remainder of the line, after stripping the spaces, is used
 297 as the help associated to the option.
 298
 299 Blank lines are ignored, and lines that don't match this specification are used
 300 as option group headers (start the line with a space to create such
 301 lines on purpose).
 302
 303 Example
 304 ~~~~~~~
 305
 306 ------------
 307 OPTS_SPEC="\
 308 some-command [options] <args>...
 309
 310 some-command does foo and bar!
 311 --
 312 h,help    show the help
 313
 314 foo       some nifty option --foo
 315 bar=      some cool option --bar with an argument
 316
 317   An option group Header
 318 C?        option C with an optional argument"
 319
 320 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 321 ------------
 322
 323 SQ-QUOTE
 324 --------
 325
 326 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 327 single line suitable for `sh(1)` `eval`. This line is made by
 328 normalizing the arguments following `--sq-quote`. Nothing other than
 329 quoting the arguments is done.
 330
 331 If you want command input to still be interpreted as usual by
 332 'git rev-parse' before the output is shell quoted, see the `--sq`
 333 option.
 334
 335 Example
 336 ~~~~~~~
 337
 338 ------------
 339 $ cat >your-git-script.sh <<\EOF
 340 #!/bin/sh
 341 args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 342 command="git frotz -n24 $args"          # and use it inside a handcrafted
 343                                         # command line
 344 eval "$command"
 345 EOF
 346
 347 $ sh your-git-script.sh "a b'c"
 348 ------------
 349
 350 EXAMPLES
 351 --------
 352
 353 * Print the object name of the current commit:
 354 +
 355 ------------
 356 $ git rev-parse --verify HEAD
 357 ------------
 358
 359 * Print the commit object name from the revision in the $REV shell variable:
 360 +
 361 ------------
 362 $ git rev-parse --verify $REV^{commit}
 363 ------------
 364 +
 365 This will error out if $REV is empty or not a valid revision.
 366
 367 * Similar to above:
 368 +
 369 ------------
 370 $ git rev-parse --default master --verify $REV
 371 ------------
 372 +
 373 but if $REV is empty, the commit object name from master will be printed.
 374
 375 GIT
 376 ---
 377 Part of the linkgit:git[1] suite