1SPECIFYING REVISIONS 2-------------------- 3 4A revision parameter '<rev>' typically, but not necessarily, names a 5commit object. It uses what is called an 'extended SHA-1' 6syntax. Here are various ways to spell object names. The 7ones listed near the end of this list name trees and 8blobs contained in a commit. 9 10'<sha1>', e.g. 'dae86e1950b1277e545cee180551750029cfe735', 'dae86e':: 11 The full SHA-1 object name (40-byte hexadecimal string), or 12 a leading substring that is unique within the repository. 13 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both 14 name the same commit object if there is no other object in 15 your repository whose object name starts with dae86e. 16 17'<describeOutput>', e.g. 'v1.7.4.2-679-g3bee7fb':: 18 Output from `git describe`; i.e. a closest tag, optionally 19 followed by a dash and a number of commits, followed by a dash, a 20 'g', and an abbreviated object name. 21 22'<refname>', e.g. 'master', 'heads/master', 'refs/heads/master':: 23 A symbolic ref name. E.g. 'master' typically means the commit 24 object referenced by 'refs/heads/master'. If you 25 happen to have both 'heads/master' and 'tags/master', you can 26 explicitly say 'heads/master' to tell Git which one you mean. 27 When ambiguous, a '<refname>' is disambiguated by taking the 28 first match in the following rules: 29 30 . If '$GIT_DIR/<refname>' exists, that is what you mean (this is usually 31 useful only for 'HEAD', 'FETCH_HEAD', 'ORIG_HEAD', 'MERGE_HEAD' 32 and 'CHERRY_PICK_HEAD'); 33 34 . otherwise, 'refs/<refname>' if it exists; 35 36 . otherwise, 'refs/tags/<refname>' if it exists; 37 38 . otherwise, 'refs/heads/<refname>' if it exists; 39 40 . otherwise, 'refs/remotes/<refname>' if it exists; 41 42 . otherwise, 'refs/remotes/<refname>/HEAD' if it exists. 43+ 44'HEAD' names the commit on which you based the changes in the working tree. 45'FETCH_HEAD' records the branch which you fetched from a remote repository 46with your last `git fetch` invocation. 47'ORIG_HEAD' is created by commands that move your 'HEAD' in a drastic 48way, to record the position of the 'HEAD' before their operation, so that 49you can easily change the tip of the branch back to the state before you ran 50them. 51'MERGE_HEAD' records the commit(s) which you are merging into your branch 52when you run `git merge`. 53'CHERRY_PICK_HEAD' records the commit which you are cherry-picking 54when you run `git cherry-pick`. 55+ 56Note that any of the 'refs/*' cases above may come either from 57the '$GIT_DIR/refs' directory or from the '$GIT_DIR/packed-refs' file. 58While the ref name encoding is unspecified, UTF-8 is preferred as 59some output processing may assume ref names in UTF-8. 60 61'<refname>@\{<date>\}', e.g. 'master@\{yesterday\}', 'HEAD@\{5 minutes ago\}':: 62 A ref followed by the suffix '@' with a date specification 63 enclosed in a brace 64 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1 65 second ago\}' or '\{1979-02-26 18:30:00\}') specifies the value 66 of the ref at a prior point in time. This suffix may only be 67 used immediately following a ref name and the ref must have an 68 existing log ('$GIT_DIR/logs/<ref>'). Note that this looks up the state 69 of your *local* ref at a given time; e.g., what was in your local 70 'master' branch last week. If you want to look at commits made during 71 certain times, see '--since' and '--until'. 72 73'<refname>@\{<n>\}', e.g. 'master@\{1\}':: 74 A ref followed by the suffix '@' with an ordinal specification 75 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') specifies 76 the n-th prior value of that ref. For example 'master@\{1\}' 77 is the immediate prior value of 'master' while 'master@\{5\}' 78 is the 5th prior value of 'master'. This suffix may only be used 79 immediately following a ref name and the ref must have an existing 80 log ('$GIT_DIR/logs/<refname>'). 81 82'@\{<n>\}', e.g. '@\{1\}':: 83 You can use the '@' construct with an empty ref part to get at a 84 reflog entry of the current branch. For example, if you are on 85 branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'. 86 87'@\{-<n>\}', e.g. '@\{-1\}':: 88 The construct '@\{-<n>\}' means the <n>th branch checked out 89 before the current one. 90 91'<branchname>@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}':: 92 The suffix '@\{upstream\}' to a branchname (short form '<branchname>@\{u\}') 93 refers to the branch that the branch specified by branchname is set to build on 94 top of. A missing branchname defaults to the current one. 95 96'<rev>{caret}', e.g. 'HEAD{caret}, v1.5.1{caret}0':: 97 A suffix '{caret}' to a revision parameter means the first parent of 98 that commit object. '{caret}<n>' means the <n>th parent (i.e. 99 '<rev>{caret}' 100 is equivalent to '<rev>{caret}1'). As a special rule, 101 '<rev>{caret}0' means the commit itself and is used when '<rev>' is the 102 object name of a tag object that refers to a commit object. 103 104'<rev>{tilde}<n>', e.g. 'master{tilde}3':: 105 A suffix '{tilde}<n>' to a revision parameter means the commit 106 object that is the <n>th generation ancestor of the named 107 commit object, following only the first parents. I.e. '<rev>{tilde}3' is 108 equivalent to '<rev>{caret}{caret}{caret}' which is equivalent to 109 '<rev>{caret}1{caret}1{caret}1'. See below for an illustration of 110 the usage of this form. 111 112'<rev>{caret}\{<type>\}', e.g. 'v0.99.8{caret}\{commit\}':: 113 A suffix '{caret}' followed by an object type name enclosed in 114 brace pair means dereference the object at '<rev>' recursively until 115 an object of type '<type>' is found or the object cannot be 116 dereferenced anymore (in which case, barf). 117 For example, if '<rev>' is a commit-ish, '<rev>{caret}\{commit\}' 118 describes the corresponding commit object. 119 Similarly, if '<rev>' is a tree-ish, '<rev>{caret}\{tree\}' 120 describes the corresponding tree object. 121 '<rev>{caret}0' 122 is a short-hand for '<rev>{caret}\{commit\}'. 123+ 124'rev{caret}\{object\}' can be used to make sure 'rev' names an 125object that exists, without requiring 'rev' to be a tag, and 126without dereferencing 'rev'; because a tag is already an object, 127it does not have to be dereferenced even once to get to an object. 128 129'<rev>{caret}\{\}', e.g. 'v0.99.8{caret}\{\}':: 130 A suffix '{caret}' followed by an empty brace pair 131 means the object could be a tag, 132 and dereference the tag recursively until a non-tag object is 133 found. 134 135'<rev>{caret}\{/<text>\}', e.g. 'HEAD^{/fix nasty bug}':: 136 A suffix '{caret}' to a revision parameter, followed by a brace 137 pair that contains a text led by a slash, 138 is the same as the ':/fix nasty bug' syntax below except that 139 it returns the youngest matching commit which is reachable from 140 the '<rev>' before '{caret}'. 141 142':/<text>', e.g. ':/fix nasty bug':: 143 A colon, followed by a slash, followed by a text, names 144 a commit whose commit message matches the specified regular expression. 145 This name returns the youngest matching commit which is 146 reachable from any ref. If the commit message starts with a 147 '!' you have to repeat that; the special sequence ':/!', 148 followed by something else than '!', is reserved for now. 149 The regular expression can match any part of the commit message. To 150 match messages starting with a string, one can use e.g. ':/^foo'. 151 152'<rev>:<path>', e.g. 'HEAD:README', ':README', 'master:./README':: 153 A suffix ':' followed by a path names the blob or tree 154 at the given path in the tree-ish object named by the part 155 before the colon. 156 ':path' (with an empty part before the colon) 157 is a special case of the syntax described next: content 158 recorded in the index at the given path. 159 A path starting with './' or '../' is relative to the current working directory. 160 The given path will be converted to be relative to the working tree's root directory. 161 This is most useful to address a blob or tree from a commit or tree that has 162 the same tree structure as the working tree. 163 164':<n>:<path>', e.g. ':0:README', ':README':: 165 A colon, optionally followed by a stage number (0 to 3) and a 166 colon, followed by a path, names a blob object in the 167 index at the given path. A missing stage number (and the colon 168 that follows it) names a stage 0 entry. During a merge, stage 169 1 is the common ancestor, stage 2 is the target branch's version 170 (typically the current branch), and stage 3 is the version from 171 the branch which is being merged. 172 173Here is an illustration, by Jon Loeliger. Both commit nodes B 174and C are parents of commit node A. Parent commits are ordered 175left-to-right. 176 177........................................ 178G H I J 179 \ / \ / 180 D E F 181 \ | / \ 182 \ | / | 183 \|/ | 184 B C 185 \ / 186 \ / 187 A 188........................................ 189 190 A = = A^0 191 B = A^ = A^1 = A~1 192 C = A^2 = A^2 193 D = A^^ = A^1^1 = A~2 194 E = B^2 = A^^2 195 F = B^3 = A^^3 196 G = A^^^ = A^1^1^1 = A~3 197 H = D^2 = B^^2 = A^^^2 = A~2^2 198 I = F^ = B^3^ = A^^3^ 199 J = F^2 = B^3^2 = A^^3^2 200 201 202SPECIFYING RANGES 203----------------- 204 205History traversing commands such as `git log` operate on a set 206of commits, not just a single commit. To these commands, 207specifying a single revision with the notation described in the 208previous section means the set of commits reachable from that 209commit, following the commit ancestry chain. 210 211To exclude commits reachable from a commit, a prefix '{caret}' 212notation is used. E.g. '{caret}r1 r2' means commits reachable 213from 'r2' but exclude the ones reachable from 'r1'. 214 215This set operation appears so often that there is a shorthand 216for it. When you have two commits 'r1' and 'r2' (named according 217to the syntax explained in SPECIFYING REVISIONS above), you can ask 218for commits that are reachable from r2 excluding those that are reachable 219from r1 by '{caret}r1 r2' and it can be written as 'r1..r2'. 220 221A similar notation 'r1\...r2' is called symmetric difference 222of 'r1' and 'r2' and is defined as 223'r1 r2 --not $(git merge-base --all r1 r2)'. 224It is the set of commits that are reachable from either one of 225'r1' or 'r2' but not from both. 226 227In these two shorthands, you can omit one end and let it default to HEAD. 228For example, 'origin..' is a shorthand for 'origin..HEAD' and asks "What 229did I do since I forked from the origin branch?" Similarly, '..origin' 230is a shorthand for 'HEAD..origin' and asks "What did the origin do since 231I forked from them?" Note that '..' would mean 'HEAD..HEAD' which is an 232empty range that is both reachable and unreachable from HEAD. 233 234Two other shorthands for naming a set that is formed by a commit 235and its parent commits exist. The 'r1{caret}@' notation means all 236parents of 'r1'. 'r1{caret}!' includes commit 'r1' but excludes 237all of its parents. 238 239To summarize: 240 241'<rev>':: 242 Include commits that are reachable from (i.e. ancestors of) 243 <rev>. 244 245'{caret}<rev>':: 246 Exclude commits that are reachable from (i.e. ancestors of) 247 <rev>. 248 249'<rev1>..<rev2>':: 250 Include commits that are reachable from <rev2> but exclude 251 those that are reachable from <rev1>. When either <rev1> or 252 <rev2> is omitted, it defaults to 'HEAD'. 253 254'<rev1>\...<rev2>':: 255 Include commits that are reachable from either <rev1> or 256 <rev2> but exclude those that are reachable from both. When 257 either <rev1> or <rev2> is omitted, it defaults to 'HEAD'. 258 259'<rev>{caret}@', e.g. 'HEAD{caret}@':: 260 A suffix '{caret}' followed by an at sign is the same as listing 261 all parents of '<rev>' (meaning, include anything reachable from 262 its parents, but not the commit itself). 263 264'<rev>{caret}!', e.g. 'HEAD{caret}!':: 265 A suffix '{caret}' followed by an exclamation mark is the same 266 as giving commit '<rev>' and then all its parents prefixed with 267 '{caret}' to exclude them (and their ancestors). 268 269Here are a handful of examples: 270 271 D G H D 272 D F G H I J D F 273 ^G D H D 274 ^D B E I J F B 275 B..C C 276 B...C G H D E B C 277 ^D B C E I J F B C 278 C I J F C 279 C^@ I J F 280 C^! C 281 F^! D G H D F