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--is-inside-git-dir:: 93 When the current working directory is below the repository 94 directory print "true", otherwise "false". 95 96--is-bare-repository:: 97 When the repository is bare print "true", otherwise "false". 98 99--short, --short=number:: 100 Instead of outputting the full SHA1 values of object names try to 101 abbreviate them to a shorter unique name. When no length is specified 102 7 is used. The minimum length is 4. 103 104--since=datestring, --after=datestring:: 105 Parses the date string, and outputs corresponding 106 --max-age= parameter for git-rev-list command. 107 108--until=datestring, --before=datestring:: 109 Parses the date string, and outputs corresponding 110 --min-age= parameter for git-rev-list command. 111 112<args>...:: 113 Flags and parameters to be parsed. 114 115 116SPECIFYING REVISIONS 117-------------------- 118 119A revision parameter typically, but not necessarily, names a 120commit object. They use what is called an 'extended SHA1' 121syntax. Here are various ways to spell object names. The 122ones listed near the end of this list are to name trees and 123blobs contained in a commit. 124 125* The full SHA1 object name (40-byte hexadecimal string), or 126 a substring of such that is unique within the repository. 127 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both 128 name the same commit object if there are no other object in 129 your repository whose object name starts with dae86e. 130 131* An output from `git-describe`; i.e. a closest tag, followed by a 132 dash, a `g`, and an abbreviated object name. 133 134* A symbolic ref name. E.g. 'master' typically means the commit 135 object referenced by $GIT_DIR/refs/heads/master. If you 136 happen to have both heads/master and tags/master, you can 137 explicitly say 'heads/master' to tell git which one you mean. 138 When ambiguous, a `<name>` is disambiguated by taking the 139 first match in the following rules: 140 141 . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually 142 useful only for `HEAD`, `FETCH_HEAD` and `MERGE_HEAD`); 143 144 . otherwise, `$GIT_DIR/refs/<name>` if exists; 145 146 . otherwise, `$GIT_DIR/refs/tags/<name>` if exists; 147 148 . otherwise, `$GIT_DIR/refs/heads/<name>` if exists; 149 150 . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists; 151 152 . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists. 153 154* A ref followed by the suffix '@' with a date specification 155 enclosed in a brace 156 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1 157 second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value 158 of the ref at a prior point in time. This suffix may only be 159 used immediately following a ref name and the ref must have an 160 existing log ($GIT_DIR/logs/<ref>). 161 162* A ref followed by the suffix '@' with an ordinal specification 163 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify 164 the n-th prior value of that ref. For example 'master@\{1\}' 165 is the immediate prior value of 'master' while 'master@\{5\}' 166 is the 5th prior value of 'master'. This suffix may only be used 167 immediately following a ref name and the ref must have an existing 168 log ($GIT_DIR/logs/<ref>). 169 170* You can use the '@' construct with an empty ref part to get at a 171 reflog of the current branch. For example, if you are on the 172 branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'. 173 174* A suffix '{caret}' to a revision parameter means the first parent of 175 that commit object. '{caret}<n>' means the <n>th parent (i.e. 176 'rev{caret}' 177 is equivalent to 'rev{caret}1'). As a special rule, 178 'rev{caret}0' means the commit itself and is used when 'rev' is the 179 object name of a tag object that refers to a commit object. 180 181* A suffix '{tilde}<n>' to a revision parameter means the commit 182 object that is the <n>th generation grand-parent of the named 183 commit object, following only the first parent. I.e. rev~3 is 184 equivalent to rev{caret}{caret}{caret} which is equivalent to 185 rev{caret}1{caret}1{caret}1. See below for a illustration of 186 the usage of this form. 187 188* A suffix '{caret}' followed by an object type name enclosed in 189 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object 190 could be a tag, and dereference the tag recursively until an 191 object of that type is found or the object cannot be 192 dereferenced anymore (in which case, barf). `rev{caret}0` 193 introduced earlier is a short-hand for `rev{caret}\{commit\}`. 194 195* A suffix '{caret}' followed by an empty brace pair 196 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag, 197 and dereference the tag recursively until a non-tag object is 198 found. 199 200* A colon, followed by a slash, followed by a text: this names 201 a commit whose commit message starts with the specified text. 202 This name returns the youngest matching commit which is 203 reachable from any ref. If the commit message starts with a 204 '!', you have to repeat that; the special sequence ':/!', 205 followed by something else than '!' is reserved for now. 206 207* A suffix ':' followed by a path; this names the blob or tree 208 at the given path in the tree-ish object named by the part 209 before the colon. 210 211* A colon, optionally followed by a stage number (0 to 3) and a 212 colon, followed by a path; this names a blob object in the 213 index at the given path. Missing stage number (and the colon 214 that follows it) names an stage 0 entry. 215 216Here is an illustration, by Jon Loeliger. Both node B and C are 217a commit parents of commit node A. Parent commits are ordered 218left-to-right. 219 220 G H I J 221 \ / \ / 222 D E F 223 \ | / \ 224 \ | / | 225 \|/ | 226 B C 227 \ / 228 \ / 229 A 230 231 A = = A^0 232 B = A^ = A^1 = A~1 233 C = A^2 = A^2 234 D = A^^ = A^1^1 = A~2 235 E = B^2 = A^^2 236 F = B^3 = A^^3 237 G = A^^^ = A^1^1^1 = A~3 238 H = D^2 = B^^2 = A^^^2 = A~2^2 239 I = F^ = B^3^ = A^^3^ 240 J = F^2 = B^3^2 = A^^3^2 241 242 243SPECIFYING RANGES 244----------------- 245 246History traversing commands such as `git-log` operate on a set 247of commits, not just a single commit. To these commands, 248specifying a single revision with the notation described in the 249previous section means the set of commits reachable from that 250commit, following the commit ancestry chain. 251 252To exclude commits reachable from a commit, a prefix `{caret}` 253notation is used. E.g. "`{caret}r1 r2`" means commits reachable 254from `r2` but exclude the ones reachable from `r1`. 255 256This set operation appears so often that there is a shorthand 257for it. "`r1..r2`" is equivalent to "`{caret}r1 r2`". It is 258the difference of two sets (subtract the set of commits 259reachable from `r1` from the set of commits reachable from 260`r2`). 261 262A similar notation "`r1\...r2`" is called symmetric difference 263of `r1` and `r2` and is defined as 264"`r1 r2 --not $(git-merge-base --all r1 r2)`". 265It is the set of commits that are reachable from either one of 266`r1` or `r2` but not from both. 267 268Two other shorthands for naming a set that is formed by a commit 269and its parent commits exists. `r1{caret}@` notation means all 270parents of `r1`. `r1{caret}!` includes commit `r1` but excludes 271its all parents. 272 273Here are a handful examples: 274 275 D G H D 276 D F G H I J D F 277 ^G D H D 278 ^D B E I J F B 279 B...C G H D E B C 280 ^D B C E I J F B C 281 C^@ I J F 282 F^! D G H D F 283 284Author 285------ 286Written by Linus Torvalds <torvalds@osdl.org> and 287Junio C Hamano <junkio@cox.net> 288 289Documentation 290-------------- 291Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>. 292 293GIT 294--- 295Part of the gitlink:git[7] suite 296