Documentation / git-rev-parse.txton commit Merge branch 'fc/trivial' (152a9c1)
   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
  53Options 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
  70Options 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+
  83This can be used to convert arguments to a command run in a subdirectory
  84so that they can still be used after moving to the top-level of the
  85repository.  For example:
  86+
  87----
  88prefix=$(git rev-parse --show-prefix)
  89cd "$(git rev-parse --show-toplevel)"
  90eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
  91----
  92
  93--verify::
  94        Verify that exactly one parameter is provided, and that it
  95        can be turned into a raw 20-byte SHA-1 that can be used to
  96        access the object database. If so, emit it to the standard
  97        output; otherwise, error out.
  98+
  99If you want to make sure that the output actually names an object in
 100your object database and/or can be used as a specific type of object
 101you require, you can add "^{type}" peeling operator to the parameter.
 102For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
 103names an existing object that is a commit-ish (i.e. a commit, or an
 104annotated tag that points at a commit).  To make sure that `$VAR`
 105names an existing object of any type, `git rev-parse "$VAR^{object}"`
 106can 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
 152Options 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+
 165If a `pattern` is given, only refs matching the given shell glob are
 166shown.  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
 182Options 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+
 196If `$GIT_DIR` is not defined and the current directory
 197is not detected to lie in a Git repository or work tree
 198print 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
 230Other 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
 247include::revisions.txt[]
 248
 249PARSEOPT
 250--------
 251
 252In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 253scripts 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
 256It takes on the standard input the specification of the options to parse and
 257understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 258to replace the arguments with normalized ones.  In case of error, it outputs
 259usage on the standard error stream, and exits with code 129.
 260
 261Note: Make sure you quote the result when passing it to `eval`.  See
 262below for an example.
 263
 264Input Format
 265~~~~~~~~~~~~
 266
 267'git rev-parse --parseopt' input format is fully text based. It has two parts,
 268separated by a line that contains only `--`. The lines before the separator
 269(should be more than one) are used for the usage.
 270The lines after the separator describe the options.
 271
 272Each 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
 296The remainder of the line, after stripping the spaces, is used
 297as the help associated to the option.
 298
 299Blank lines are ignored, and lines that don't match this specification are used
 300as option group headers (start the line with a space to create such
 301lines on purpose).
 302
 303Example
 304~~~~~~~
 305
 306------------
 307OPTS_SPEC="\
 308some-command [options] <args>...
 309
 310some-command does foo and bar!
 311--
 312h,help    show the help
 313
 314foo       some nifty option --foo
 315bar=      some cool option --bar with an argument
 316
 317  An option group Header
 318C?        option C with an optional argument"
 319
 320eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 321------------
 322
 323SQ-QUOTE
 324--------
 325
 326In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 327single line suitable for `sh(1)` `eval`. This line is made by
 328normalizing the arguments following `--sq-quote`. Nothing other than
 329quoting the arguments is done.
 330
 331If you want command input to still be interpreted as usual by
 332'git rev-parse' before the output is shell quoted, see the `--sq`
 333option.
 334
 335Example
 336~~~~~~~
 337
 338------------
 339$ cat >your-git-script.sh <<\EOF
 340#!/bin/sh
 341args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 342command="git frotz -n24 $args"          # and use it inside a handcrafted
 343                                        # command line
 344eval "$command"
 345EOF
 346
 347$ sh your-git-script.sh "a b'c"
 348------------
 349
 350EXAMPLES
 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+
 365This 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+
 373but if $REV is empty, the commit object name from master will be printed.
 374
 375GIT
 376---
 377Part of the linkgit:git[1] suite