Documentation / git-rev-parse.txton commit check-ref-format doc: de-emphasize the implementation detail of a ref (a0a7e9e)
   1git-rev-parse(1)
   2================
   3
   4NAME
   5----
   6git-rev-parse - Pick out and massage parameters
   7
   8
   9SYNOPSIS
  10--------
  11'git rev-parse' [ --option ] <args>...
  12
  13DESCRIPTION
  14-----------
  15
  16Many git porcelainish commands take mixture of flags
  17(i.e. parameters that begin with a dash '-') and parameters
  18meant for the underlying 'git rev-list' command they use internally
  19and flags and parameters for the other commands they use
  20downstream of 'git rev-list'.  This command is used to
  21distinguish between them.
  22
  23
  24OPTIONS
  25-------
  26--parseopt::
  27        Use 'git rev-parse' in option parsing mode (see PARSEOPT section below).
  28
  29--keep-dashdash::
  30        Only meaningful in `--parseopt` mode. Tells the option parser to echo
  31        out the first `--` met instead of skipping it.
  32
  33--stop-at-non-option::
  34        Only meaningful in `--parseopt` mode.  Lets the option parser stop at
  35        the first non-option argument.  This can be used to parse sub-commands
  36        that take options themselves.
  37
  38--sq-quote::
  39        Use 'git rev-parse' in shell quoting mode (see SQ-QUOTE
  40        section below). In contrast to the `--sq` option below, this
  41        mode does only quoting. Nothing else is done to command input.
  42
  43--revs-only::
  44        Do not output flags and parameters not meant for
  45        'git rev-list' command.
  46
  47--no-revs::
  48        Do not output flags and parameters meant for
  49        'git rev-list' command.
  50
  51--flags::
  52        Do not output non-flag parameters.
  53
  54--no-flags::
  55        Do not output flag parameters.
  56
  57--default <arg>::
  58        If there is no parameter given by the user, use `<arg>`
  59        instead.
  60
  61--verify::
  62        The parameter given must be usable as a single, valid
  63        object name.  Otherwise barf and abort.
  64
  65-q::
  66--quiet::
  67        Only meaningful in `--verify` mode. Do not output an error
  68        message if the first argument is not a valid object name;
  69        instead exit with non-zero status silently.
  70
  71--sq::
  72        Usually the output is made one line per flag and
  73        parameter.  This option makes output a single line,
  74        properly quoted for consumption by shell.  Useful when
  75        you expect your parameter to contain whitespaces and
  76        newlines (e.g. when using pickaxe `-S` with
  77        'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
  78        the command input is still interpreted as usual.
  79
  80--not::
  81        When showing object names, prefix them with '{caret}' and
  82        strip '{caret}' prefix from the object names that already have
  83        one.
  84
  85--symbolic::
  86        Usually the object names are output in SHA1 form (with
  87        possible '{caret}' prefix); this option makes them output in a
  88        form as close to the original input as possible.
  89
  90--symbolic-full-name::
  91        This is similar to \--symbolic, but it omits input that
  92        are not refs (i.e. branch or tag names; or more
  93        explicitly disambiguating "heads/master" form, when you
  94        want to name the "master" branch when there is an
  95        unfortunately named tag "master"), and show them as full
  96        refnames (e.g. "refs/heads/master").
  97
  98--abbrev-ref[=(strict|loose)]::
  99        A non-ambiguous short name of the objects name.
 100        The option core.warnAmbiguousRefs is used to select the strict
 101        abbreviation mode.
 102
 103--all::
 104        Show all refs found in `refs/`.
 105
 106--branches[=pattern]::
 107--tags[=pattern]::
 108--remotes[=pattern]::
 109        Show all branches, tags, or remote-tracking branches,
 110        respectively (i.e., refs found in `refs/heads`,
 111        `refs/tags`, or `refs/remotes`, respectively).
 112+
 113If a `pattern` is given, only refs matching the given shell glob are
 114shown.  If the pattern does not contain a globbing character (`?`,
 115`{asterisk}`, or `[`), it is turned into a prefix match by
 116appending `/{asterisk}`.
 117
 118--glob=pattern::
 119        Show all refs matching the shell glob pattern `pattern`. If
 120        the pattern does not start with `refs/`, this is automatically
 121        prepended.  If the pattern does not contain a globbing
 122        character (`?`, `{asterisk}`, or `[`), it is turned into a prefix
 123        match by appending `/{asterisk}`.
 124
 125--show-toplevel::
 126        Show the absolute path of the top-level directory.
 127
 128--show-prefix::
 129        When the command is invoked from a subdirectory, show the
 130        path of the current directory relative to the top-level
 131        directory.
 132
 133--show-cdup::
 134        When the command is invoked from a subdirectory, show the
 135        path of the top-level directory relative to the current
 136        directory (typically a sequence of "../", or an empty string).
 137
 138--git-dir::
 139        Show `$GIT_DIR` if defined. Otherwise show the path to
 140        the .git directory, relative to the current directory.
 141+
 142If `$GIT_DIR` is not defined and the current directory
 143is not detected to lie in a git repository or work tree
 144print a message to stderr and exit with nonzero status.
 145
 146--is-inside-git-dir::
 147        When the current working directory is below the repository
 148        directory print "true", otherwise "false".
 149
 150--is-inside-work-tree::
 151        When the current working directory is inside the work tree of the
 152        repository print "true", otherwise "false".
 153
 154--is-bare-repository::
 155        When the repository is bare print "true", otherwise "false".
 156
 157--local-env-vars::
 158        List the GIT_* environment variables that are local to the
 159        repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
 160        Only the names of the variables are listed, not their value,
 161        even if they are set.
 162
 163--short::
 164--short=number::
 165        Instead of outputting the full SHA1 values of object names try to
 166        abbreviate them to a shorter unique name. When no length is specified
 167        7 is used. The minimum length is 4.
 168
 169--since=datestring::
 170--after=datestring::
 171        Parse the date string, and output the corresponding
 172        --max-age= parameter for 'git rev-list'.
 173
 174--until=datestring::
 175--before=datestring::
 176        Parse the date string, and output the corresponding
 177        --min-age= parameter for 'git rev-list'.
 178
 179<args>...::
 180        Flags and parameters to be parsed.
 181
 182
 183include::revisions.txt[]
 184
 185PARSEOPT
 186--------
 187
 188In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 189scripts the same facilities C builtins have. It works as an option normalizer
 190(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 191
 192It takes on the standard input the specification of the options to parse and
 193understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 194to replace the arguments with normalized ones.  In case of error, it outputs
 195usage on the standard error stream, and exits with code 129.
 196
 197Note: Make sure you quote the result when passing it to `eval`.  See
 198below for an example.
 199
 200Input Format
 201~~~~~~~~~~~~
 202
 203'git rev-parse --parseopt' input format is fully text based. It has two parts,
 204separated by a line that contains only `--`. The lines before the separator
 205(should be more than one) are used for the usage.
 206The lines after the separator describe the options.
 207
 208Each line of options has this format:
 209
 210------------
 211<opt_spec><flags>* SP+ help LF
 212------------
 213
 214`<opt_spec>`::
 215        its format is the short option character, then the long option name
 216        separated by a comma. Both parts are not required, though at least one
 217        is necessary. `h,help`, `dry-run` and `f` are all three correct
 218        `<opt_spec>`.
 219
 220`<flags>`::
 221        `<flags>` are of `*`, `=`, `?` or `!`.
 222        * Use `=` if the option takes an argument.
 223
 224        * Use `?` to mean that the option is optional (though its use is discouraged).
 225
 226        * Use `*` to mean that this option should not be listed in the usage
 227          generated for the `-h` argument. It's shown for `--help-all` as
 228          documented in linkgit:gitcli[7].
 229
 230        * Use `!` to not make the corresponding negated long option available.
 231
 232The remainder of the line, after stripping the spaces, is used
 233as the help associated to the option.
 234
 235Blank lines are ignored, and lines that don't match this specification are used
 236as option group headers (start the line with a space to create such
 237lines on purpose).
 238
 239Example
 240~~~~~~~
 241
 242------------
 243OPTS_SPEC="\
 244some-command [options] <args>...
 245
 246some-command does foo and bar!
 247--
 248h,help    show the help
 249
 250foo       some nifty option --foo
 251bar=      some cool option --bar with an argument
 252
 253  An option group Header
 254C?        option C with an optional argument"
 255
 256eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 257------------
 258
 259SQ-QUOTE
 260--------
 261
 262In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 263single line suitable for `sh(1)` `eval`. This line is made by
 264normalizing the arguments following `--sq-quote`. Nothing other than
 265quoting the arguments is done.
 266
 267If you want command input to still be interpreted as usual by
 268'git rev-parse' before the output is shell quoted, see the `--sq`
 269option.
 270
 271Example
 272~~~~~~~
 273
 274------------
 275$ cat >your-git-script.sh <<\EOF
 276#!/bin/sh
 277args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 278command="git frotz -n24 $args"          # and use it inside a handcrafted
 279                                        # command line
 280eval "$command"
 281EOF
 282
 283$ sh your-git-script.sh "a b'c"
 284------------
 285
 286EXAMPLES
 287--------
 288
 289* Print the object name of the current commit:
 290+
 291------------
 292$ git rev-parse --verify HEAD
 293------------
 294
 295* Print the commit object name from the revision in the $REV shell variable:
 296+
 297------------
 298$ git rev-parse --verify $REV
 299------------
 300+
 301This will error out if $REV is empty or not a valid revision.
 302
 303* Same as above:
 304+
 305------------
 306$ git rev-parse --default master --verify $REV
 307------------
 308+
 309but if $REV is empty, the commit object name from master will be printed.
 310
 311GIT
 312---
 313Part of the linkgit:git[1] suite