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 'git-rev-parse' [ --option ] <args>...
  12
  13 DESCRIPTION
  14 -----------
  15
  16 Many git Porcelainish commands take mixture of flags
  17 (i.e. parameters that begin with a dash '-') and parameters
  18 meant for underlying `git-rev-list` command they use internally
  19 and flags and parameters for other commands they use as the
  20 downstream of `git-rev-list`.  This command is used to
  21 distinguish between them.
  22
  23
  24 OPTIONS
  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 --show-prefix::
  71         When the command is invoked from a subdirectory, show the
  72         path of the current directory relative to the top-level
  73         directory.
  74
  75 --show-cdup::
  76         When the command is invoked from a subdirectory, show the
  77         path of the top-level directory relative to the current
  78         directory (typically a sequence of "../", or an empty string).
  79
  80 --since=datestring, --after=datestring::
  81         Parses the date string, and outputs corresponding
  82         --max-age= parameter for git-rev-list command.
  83
  84 --until=datestring, --before=datestring::
  85         Parses the date string, and outputs corresponding
  86         --min-age= parameter for git-rev-list command.
  87
  88 <args>...::
  89         Flags and parameters to be parsed.
  90
  91
  92 SPECIFYING REVISIONS
  93 --------------------
  94
  95 A revision parameter typically, but not necessarily, names a
  96 commit object.  They use what is called an 'extended SHA1'
  97 syntax.
  98
  99 * The full SHA1 object name (40-byte hexadecimal string), or
 100   a substring of such that is unique within the repository.
 101   E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
 102   name the same commit object if there are no other object in
 103   your repository whose object name starts with dae86e.
 104
 105 * A symbolic ref name.  E.g. 'master' typically means the commit
 106   object referenced by $GIT_DIR/refs/heads/master.  If you
 107   happen to have both heads/master and tags/master, you can
 108   explicitly say 'heads/master' to tell git which one you mean.
 109
 110 * A suffix '{caret}' to a revision parameter means the first parent of
 111   that commit object.  '{caret}<n>' means the <n>th parent (i.e.
 112   'rev{caret}'
 113   is equivalent to 'rev{caret}1').  As a special rule,
 114   'rev{caret}0' means the commit itself and is used when 'rev' is the
 115   object name of a tag object that refers to a commit object.
 116
 117 * A suffix '~<n>' to a revision parameter means the commit
 118   object that is the <n>th generation grand-parent of the named
 119   commit object, following only the first parent.  I.e. rev~3 is
 120   equivalent to rev{caret}{caret}{caret} which is equivalent to\
 121   rev{caret}1{caret}1{caret}1.
 122
 123 * A suffix '{caret}' followed by an object type name enclosed in
 124   brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
 125   could be a tag, and dereference the tag recursively until an
 126   object of that type is found or the object cannot be
 127   dereferenced anymore (in which case, barf).  `rev{caret}0`
 128   introduced earlier is a short-hand for `rev{caret}\{commit\}`.
 129
 130 * A suffix '{caret}' followed by an empty brace pair
 131   (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
 132   and dereference the tag recursively until a non-tag object is
 133   found.
 134
 135 'git-rev-parse' also accepts a prefix '{caret}' to revision parameter,
 136 which is passed to 'git-rev-list'.  Two revision parameters
 137 concatenated with '..' is a short-hand for writing a range
 138 between them.  I.e. 'r1..r2' is equivalent to saying '{caret}r1 r2'
 139
 140 Here is an illustration, by Jon Loeliger.  Both node B and C are
 141 a commit parents of commit node A.  Parent commits are ordered
 142 left-to-right.
 143
 144     G   H   I   J
 145      \ /     \ /
 146       D   E   F
 147        \  |  /
 148         \ | /
 149          \|/
 150           B     C
 151            \   /
 152             \ /
 153              A
 154
 155     A =      = A^0
 156     B = A^   = A^1     = A~1
 157     C = A^2  = A^2
 158     D = A^^  = A^1^1   = A~2
 159     E = B^2  = A^^2
 160     F = B^3  = A^^3
 161     G = A^^^ = A^1^1^1 = A~3
 162     H = D^2  = B^^2    = A^^^2  = A~2^2
 163     I = F^   = B^3^    = A^^3^
 164     J = F^2  = B^3^2   = A^^3^2
 165
 166
 167 Author
 168 ------
 169 Written by Linus Torvalds <torvalds@osdl.org> and
 170 Junio C Hamano <junkio@cox.net>
 171
 172 Documentation
 173 --------------
 174 Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
 175
 176 GIT
 177 ---
 178 Part of the gitlink:git[7] suite
 179