Documentation / git-rev-parse.txton commit Merge branch 'jc/waitpid' (b879de1)
   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 underlying `git-rev-list` command they use internally
  19and flags and parameters for other commands they use as the
  20downstream of `git-rev-list`.  This command is used to
  21distinguish between them.
  22
  23
  24OPTIONS
  25-------
  26--revs-only::
  27        Do not output flags and parameters not meant for
  28        `git-rev-list` command.
  29
  30--no-revs::
  31        Do not output flags and parameters meant for
  32        `git-rev-list` command.
  33
  34--flags::
  35        Do not output non-flag parameters.
  36
  37--no-flags::
  38        Do not output flag parameters.
  39
  40--default <arg>::
  41        If there is no parameter given by the user, use `<arg>`
  42        instead.
  43
  44--verify::
  45        The parameter given must be usable as a single, valid
  46        object name.  Otherwise barf and abort.
  47
  48--sq::
  49        Usually the output is made one line per flag and
  50        parameter.  This option makes output a single line,
  51        properly quoted for consumption by shell.  Useful when
  52        you expect your parameter to contain whitespaces and
  53        newlines (e.g. when using pickaxe `-S` with
  54        `git-diff-\*`).
  55
  56--not::
  57        When showing object names, prefix them with '{caret}' and
  58        strip '{caret}' prefix from the object names that already have
  59        one.
  60
  61--symbolic::
  62        Usually the object names are output in SHA1 form (with
  63        possible '{caret}' prefix); this option makes them output in a
  64        form as close to the original input as possible.
  65
  66
  67--all::
  68        Show all refs found in `$GIT_DIR/refs`.
  69
  70--branches::
  71        Show branch refs found in `$GIT_DIR/refs/heads`.
  72
  73--tags::
  74        Show tag refs found in `$GIT_DIR/refs/tags`.
  75
  76--remotes::
  77        Show tag refs found in `$GIT_DIR/refs/remotes`.
  78
  79--show-prefix::
  80        When the command is invoked from a subdirectory, show the
  81        path of the current directory relative to the top-level
  82        directory.
  83
  84--show-cdup::
  85        When the command is invoked from a subdirectory, show the
  86        path of the top-level directory relative to the current
  87        directory (typically a sequence of "../", or an empty string).
  88
  89--git-dir::
  90        Show `$GIT_DIR` if defined else show the path to the .git directory.
  91
  92--short, --short=number::
  93        Instead of outputting the full SHA1 values of object names try to
  94        abbreviate them to a shorter unique name. When no length is specified
  95        7 is used. The minimum length is 4.
  96
  97--since=datestring, --after=datestring::
  98        Parses the date string, and outputs corresponding
  99        --max-age= parameter for git-rev-list command.
 100
 101--until=datestring, --before=datestring::
 102        Parses the date string, and outputs corresponding
 103        --min-age= parameter for git-rev-list command.
 104
 105<args>...::
 106        Flags and parameters to be parsed.
 107
 108
 109SPECIFYING REVISIONS
 110--------------------
 111
 112A revision parameter typically, but not necessarily, names a
 113commit object.  They use what is called an 'extended SHA1'
 114syntax.
 115
 116* The full SHA1 object name (40-byte hexadecimal string), or
 117  a substring of such that is unique within the repository.
 118  E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
 119  name the same commit object if there are no other object in
 120  your repository whose object name starts with dae86e.
 121
 122* A symbolic ref name.  E.g. 'master' typically means the commit
 123  object referenced by $GIT_DIR/refs/heads/master.  If you
 124  happen to have both heads/master and tags/master, you can
 125  explicitly say 'heads/master' to tell git which one you mean.
 126
 127* A suffix '@' followed by a date specification enclosed in a brace
 128  pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
 129  second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
 130  of the ref at a prior point in time.  This suffix may only be
 131  used immediately following a ref name and the ref must have an
 132  existing log ($GIT_DIR/logs/<ref>).
 133
 134* A suffix '{caret}' to a revision parameter means the first parent of
 135  that commit object.  '{caret}<n>' means the <n>th parent (i.e.
 136  'rev{caret}'
 137  is equivalent to 'rev{caret}1').  As a special rule,
 138  'rev{caret}0' means the commit itself and is used when 'rev' is the
 139  object name of a tag object that refers to a commit object.
 140
 141* A suffix '~<n>' to a revision parameter means the commit
 142  object that is the <n>th generation grand-parent of the named
 143  commit object, following only the first parent.  I.e. rev~3 is
 144  equivalent to rev{caret}{caret}{caret} which is equivalent to\
 145  rev{caret}1{caret}1{caret}1.
 146
 147* A suffix '{caret}' followed by an object type name enclosed in
 148  brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
 149  could be a tag, and dereference the tag recursively until an
 150  object of that type is found or the object cannot be
 151  dereferenced anymore (in which case, barf).  `rev{caret}0`
 152  introduced earlier is a short-hand for `rev{caret}\{commit\}`.
 153
 154* A suffix '{caret}' followed by an empty brace pair
 155  (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
 156  and dereference the tag recursively until a non-tag object is
 157  found.
 158
 159'git-rev-parse' also accepts a prefix '{caret}' to revision parameter,
 160which is passed to 'git-rev-list'.  Two revision parameters
 161concatenated with '..' is a short-hand for writing a range
 162between them.  I.e. 'r1..r2' is equivalent to saying '{caret}r1 r2'
 163
 164Here is an illustration, by Jon Loeliger.  Both node B and C are
 165a commit parents of commit node A.  Parent commits are ordered
 166left-to-right.
 167
 168    G   H   I   J
 169     \ /     \ /
 170      D   E   F
 171       \  |  /
 172        \ | /
 173         \|/
 174          B     C
 175           \   /
 176            \ /
 177             A
 178
 179    A =      = A^0
 180    B = A^   = A^1     = A~1
 181    C = A^2  = A^2
 182    D = A^^  = A^1^1   = A~2
 183    E = B^2  = A^^2
 184    F = B^3  = A^^3
 185    G = A^^^ = A^1^1^1 = A~3
 186    H = D^2  = B^^2    = A^^^2  = A~2^2
 187    I = F^   = B^3^    = A^^3^
 188    J = F^2  = B^3^2   = A^^3^2
 189
 190
 191Author
 192------
 193Written by Linus Torvalds <torvalds@osdl.org> and
 194Junio C Hamano <junkio@cox.net>
 195
 196Documentation
 197--------------
 198Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
 199
 200GIT
 201---
 202Part of the gitlink:git[7] suite
 203