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