Documentation / git-rev-parse.txton commit rev-parse: clarify documentation for the --verify option (2db6067)
   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--parseopt::
  28        Use 'git rev-parse' in option parsing mode (see PARSEOPT section below).
  29
  30--keep-dashdash::
  31        Only meaningful in `--parseopt` mode. Tells the option parser to echo
  32        out the first `--` met instead of skipping it.
  33
  34--stop-at-non-option::
  35        Only meaningful in `--parseopt` mode.  Lets the option parser stop at
  36        the first non-option argument.  This can be used to parse sub-commands
  37        that take options themselves.
  38
  39--sq-quote::
  40        Use 'git rev-parse' in shell quoting mode (see SQ-QUOTE
  41        section below). In contrast to the `--sq` option below, this
  42        mode does only quoting. Nothing else is done to command input.
  43
  44--revs-only::
  45        Do not output flags and parameters not meant for
  46        'git rev-list' command.
  47
  48--no-revs::
  49        Do not output flags and parameters meant for
  50        'git rev-list' command.
  51
  52--flags::
  53        Do not output non-flag parameters.
  54
  55--no-flags::
  56        Do not output flag parameters.
  57
  58--default <arg>::
  59        If there is no parameter given by the user, use `<arg>`
  60        instead.
  61
  62--verify::
  63        Verify that exactly one parameter is provided, and that it
  64        can be turned into a raw 20-byte SHA-1 that can be used to
  65        access the object database. If so, emit it to the standard
  66        output; otherwise, error out.
  67+
  68If you want to make sure that the output actually names an object in
  69your object database and/or can be used as a specific type of object
  70you require, you can add "^{type}" peeling operator to the parmeter.
  71For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
  72names an existing object that is a commit-ish (i.e. a commit, or an
  73annotated tag that points at a commit).  To make sure that `$VAR`
  74names an existing object of any type, `git rev-parse "$VAR^{object}"`
  75can be used.
  76
  77-q::
  78--quiet::
  79        Only meaningful in `--verify` mode. Do not output an error
  80        message if the first argument is not a valid object name;
  81        instead exit with non-zero status silently.
  82
  83--sq::
  84        Usually the output is made one line per flag and
  85        parameter.  This option makes output a single line,
  86        properly quoted for consumption by shell.  Useful when
  87        you expect your parameter to contain whitespaces and
  88        newlines (e.g. when using pickaxe `-S` with
  89        'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
  90        the command input is still interpreted as usual.
  91
  92--not::
  93        When showing object names, prefix them with '{caret}' and
  94        strip '{caret}' prefix from the object names that already have
  95        one.
  96
  97--symbolic::
  98        Usually the object names are output in SHA1 form (with
  99        possible '{caret}' prefix); this option makes them output in a
 100        form as close to the original input as possible.
 101
 102--symbolic-full-name::
 103        This is similar to \--symbolic, but it omits input that
 104        are not refs (i.e. branch or tag names; or more
 105        explicitly disambiguating "heads/master" form, when you
 106        want to name the "master" branch when there is an
 107        unfortunately named tag "master"), and show them as full
 108        refnames (e.g. "refs/heads/master").
 109
 110--abbrev-ref[=(strict|loose)]::
 111        A non-ambiguous short name of the objects name.
 112        The option core.warnAmbiguousRefs is used to select the strict
 113        abbreviation mode.
 114
 115--disambiguate=<prefix>::
 116        Show every object whose name begins with the given prefix.
 117        The <prefix> must be at least 4 hexadecimal digits long to
 118        avoid listing each and every object in the repository by
 119        mistake.
 120
 121--all::
 122        Show all refs found in `refs/`.
 123
 124--branches[=pattern]::
 125--tags[=pattern]::
 126--remotes[=pattern]::
 127        Show all branches, tags, or remote-tracking branches,
 128        respectively (i.e., refs found in `refs/heads`,
 129        `refs/tags`, or `refs/remotes`, respectively).
 130+
 131If a `pattern` is given, only refs matching the given shell glob are
 132shown.  If the pattern does not contain a globbing character (`?`,
 133`*`, or `[`), it is turned into a prefix match by appending `/*`.
 134
 135--glob=pattern::
 136        Show all refs matching the shell glob pattern `pattern`. If
 137        the pattern does not start with `refs/`, this is automatically
 138        prepended.  If the pattern does not contain a globbing
 139        character (`?`, `*`, or `[`), it is turned into a prefix
 140        match by appending `/*`.
 141
 142--show-toplevel::
 143        Show the absolute path of the top-level directory.
 144
 145--show-prefix::
 146        When the command is invoked from a subdirectory, show the
 147        path of the current directory relative to the top-level
 148        directory.
 149
 150--show-cdup::
 151        When the command is invoked from a subdirectory, show the
 152        path of the top-level directory relative to the current
 153        directory (typically a sequence of "../", or an empty string).
 154
 155--git-dir::
 156        Show `$GIT_DIR` if defined. Otherwise show the path to
 157        the .git directory. The path shown, when relative, is
 158        relative to the current working directory.
 159+
 160If `$GIT_DIR` is not defined and the current directory
 161is not detected to lie in a git repository or work tree
 162print a message to stderr and exit with nonzero status.
 163
 164--is-inside-git-dir::
 165        When the current working directory is below the repository
 166        directory print "true", otherwise "false".
 167
 168--is-inside-work-tree::
 169        When the current working directory is inside the work tree of the
 170        repository print "true", otherwise "false".
 171
 172--is-bare-repository::
 173        When the repository is bare print "true", otherwise "false".
 174
 175--local-env-vars::
 176        List the GIT_* environment variables that are local to the
 177        repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
 178        Only the names of the variables are listed, not their value,
 179        even if they are set.
 180
 181--short::
 182--short=number::
 183        Instead of outputting the full SHA1 values of object names try to
 184        abbreviate them to a shorter unique name. When no length is specified
 185        7 is used. The minimum length is 4.
 186
 187--since=datestring::
 188--after=datestring::
 189        Parse the date string, and output the corresponding
 190        --max-age= parameter for 'git rev-list'.
 191
 192--until=datestring::
 193--before=datestring::
 194        Parse the date string, and output the corresponding
 195        --min-age= parameter for 'git rev-list'.
 196
 197<args>...::
 198        Flags and parameters to be parsed.
 199
 200--resolve-git-dir <path>::
 201        Check if <path> is a valid git-dir or a git-file pointing to a valid
 202        git-dir. If <path> is a valid git-dir the resolved path to git-dir will
 203        be printed.
 204
 205include::revisions.txt[]
 206
 207PARSEOPT
 208--------
 209
 210In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
 211scripts the same facilities C builtins have. It works as an option normalizer
 212(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
 213
 214It takes on the standard input the specification of the options to parse and
 215understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
 216to replace the arguments with normalized ones.  In case of error, it outputs
 217usage on the standard error stream, and exits with code 129.
 218
 219Note: Make sure you quote the result when passing it to `eval`.  See
 220below for an example.
 221
 222Input Format
 223~~~~~~~~~~~~
 224
 225'git rev-parse --parseopt' input format is fully text based. It has two parts,
 226separated by a line that contains only `--`. The lines before the separator
 227(should be more than one) are used for the usage.
 228The lines after the separator describe the options.
 229
 230Each line of options has this format:
 231
 232------------
 233<opt_spec><flags>* SP+ help LF
 234------------
 235
 236`<opt_spec>`::
 237        its format is the short option character, then the long option name
 238        separated by a comma. Both parts are not required, though at least one
 239        is necessary. `h,help`, `dry-run` and `f` are all three correct
 240        `<opt_spec>`.
 241
 242`<flags>`::
 243        `<flags>` are of `*`, `=`, `?` or `!`.
 244        * Use `=` if the option takes an argument.
 245
 246        * Use `?` to mean that the option is optional (though its use is discouraged).
 247
 248        * Use `*` to mean that this option should not be listed in the usage
 249          generated for the `-h` argument. It's shown for `--help-all` as
 250          documented in linkgit:gitcli[7].
 251
 252        * Use `!` to not make the corresponding negated long option available.
 253
 254The remainder of the line, after stripping the spaces, is used
 255as the help associated to the option.
 256
 257Blank lines are ignored, and lines that don't match this specification are used
 258as option group headers (start the line with a space to create such
 259lines on purpose).
 260
 261Example
 262~~~~~~~
 263
 264------------
 265OPTS_SPEC="\
 266some-command [options] <args>...
 267
 268some-command does foo and bar!
 269--
 270h,help    show the help
 271
 272foo       some nifty option --foo
 273bar=      some cool option --bar with an argument
 274
 275  An option group Header
 276C?        option C with an optional argument"
 277
 278eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
 279------------
 280
 281SQ-QUOTE
 282--------
 283
 284In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
 285single line suitable for `sh(1)` `eval`. This line is made by
 286normalizing the arguments following `--sq-quote`. Nothing other than
 287quoting the arguments is done.
 288
 289If you want command input to still be interpreted as usual by
 290'git rev-parse' before the output is shell quoted, see the `--sq`
 291option.
 292
 293Example
 294~~~~~~~
 295
 296------------
 297$ cat >your-git-script.sh <<\EOF
 298#!/bin/sh
 299args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
 300command="git frotz -n24 $args"          # and use it inside a handcrafted
 301                                        # command line
 302eval "$command"
 303EOF
 304
 305$ sh your-git-script.sh "a b'c"
 306------------
 307
 308EXAMPLES
 309--------
 310
 311* Print the object name of the current commit:
 312+
 313------------
 314$ git rev-parse --verify HEAD
 315------------
 316
 317* Print the commit object name from the revision in the $REV shell variable:
 318+
 319------------
 320$ git rev-parse --verify $REV^{commit}
 321------------
 322+
 323This will error out if $REV is empty or not a valid revision.
 324
 325* Similar to above:
 326+
 327------------
 328$ git rev-parse --default master --verify $REV
 329------------
 330+
 331but if $REV is empty, the commit object name from master will be printed.
 332
 333GIT
 334---
 335Part of the linkgit:git[1] suite