X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=Documentation%2Frevisions.txt;h=b290b617d4a59ee2ae6b62f2eebd9e86f71c4802;hb=e9f3f8b6f4141dae526e9792ba6dede7aa038622;hp=b994bab1a0a7012be8b86e6e756839639c9637ac;hpb=83456b13528c47be1ee08924f31cca565b92342f;p=git.git diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt index b994bab1a..b290b617d 100644 --- a/Documentation/revisions.txt +++ b/Documentation/revisions.txt @@ -1,62 +1,66 @@ SPECIFYING REVISIONS -------------------- -A revision parameter typically, but not necessarily, names a -commit object. They use what is called an 'extended SHA1' +A revision parameter '' typically, but not necessarily, names a +commit object. It uses what is called an 'extended SHA1' syntax. Here are various ways to spell object names. The -ones listed near the end of this list are to name trees and +ones listed near the end of this list name trees and blobs contained in a commit. -* The full SHA1 object name (40-byte hexadecimal string), or - a substring of such that is unique within the repository. +'', e.g. 'dae86e1950b1277e545cee180551750029cfe735', 'dae86e':: + The full SHA1 object name (40-byte hexadecimal string), or + a leading substring that is unique within the repository. E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both - name the same commit object if there are no other object in + name the same commit object if there is no other object in your repository whose object name starts with dae86e. -* An output from `git describe`; i.e. a closest tag, optionally +'', e.g. 'v1.7.4.2-679-g3bee7fb':: + Output from `git describe`; i.e. a closest tag, optionally followed by a dash and a number of commits, followed by a dash, a 'g', and an abbreviated object name. -* A symbolic ref name. E.g. 'master' typically means the commit +'', e.g. 'master', 'heads/master', 'refs/heads/master':: + A symbolic ref name. E.g. 'master' typically means the commit object referenced by 'refs/heads/master'. If you happen to have both 'heads/master' and 'tags/master', you can explicitly say 'heads/master' to tell git which one you mean. When ambiguous, a '' is disambiguated by taking the first match in the following rules: - . if '$GIT_DIR/' exists, that is what you mean (this is usually + . If '$GIT_DIR/' exists, that is what you mean (this is usually useful only for 'HEAD', 'FETCH_HEAD', 'ORIG_HEAD', 'MERGE_HEAD' and 'CHERRY_PICK_HEAD'); - . otherwise, 'refs/' if exists; + . otherwise, 'refs/' if it exists; - . otherwise, 'refs/tags/' if exists; + . otherwise, 'refs/tags/' if it exists; - . otherwise, 'refs/heads/' if exists; + . otherwise, 'refs/heads/' if it exists; - . otherwise, 'refs/remotes/' if exists; + . otherwise, 'refs/remotes/' if it exists; - . otherwise, 'refs/remotes//HEAD' if exists. + . otherwise, 'refs/remotes//HEAD' if it exists. + -'HEAD' names the commit your changes in the working tree is based on. -'FETCH_HEAD' records the branch you fetched from a remote repository +'HEAD' names the commit on which you based the changes in the working tree. +'FETCH_HEAD' records the branch which you fetched from a remote repository with your last `git fetch` invocation. -'ORIG_HEAD' is created by commands that moves your 'HEAD' in a drastic +'ORIG_HEAD' is created by commands that move your 'HEAD' in a drastic way, to record the position of the 'HEAD' before their operation, so that -you can change the tip of the branch back to the state before you ran -them easily. -'MERGE_HEAD' records the commit(s) you are merging into your branch +you can easily change the tip of the branch back to the state before you ran +them. +'MERGE_HEAD' records the commit(s) which you are merging into your branch when you run `git merge`. -'CHERRY_PICK_HEAD' records the commit you are cherry-picking +'CHERRY_PICK_HEAD' records the commit which you are cherry-picking when you run `git cherry-pick`. + Note that any of the 'refs/*' cases above may come either from the '$GIT_DIR/refs' directory or from the '$GIT_DIR/packed-refs' file. -* A ref followed by the suffix '@' with a date specification +'@\{\}', e.g. 'master@\{yesterday\}', 'HEAD@\{5 minutes ago\}':: + A ref followed by the suffix '@' with a date specification enclosed in a brace pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1 - second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value + second ago\}' or '\{1979-02-26 18:30:00\}') specifies the value of the ref at a prior point in time. This suffix may only be used immediately following a ref name and the ref must have an existing log ('$GIT_DIR/logs/'). Note that this looks up the state @@ -64,84 +68,96 @@ the '$GIT_DIR/refs' directory or from the '$GIT_DIR/packed-refs' file. 'master' branch last week. If you want to look at commits made during certain times, see '--since' and '--until'. -* A ref followed by the suffix '@' with an ordinal specification - enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify +'@\{\}', e.g. 'master@\{1\}':: + A ref followed by the suffix '@' with an ordinal specification + enclosed in a brace pair (e.g. '\{1\}', '\{15\}') specifies the n-th prior value of that ref. For example 'master@\{1\}' is the immediate prior value of 'master' while 'master@\{5\}' is the 5th prior value of 'master'. This suffix may only be used immediately following a ref name and the ref must have an existing - log ('$GIT_DIR/logs/'). + log ('$GIT_DIR/logs/'). -* You can use the '@' construct with an empty ref part to get at a - reflog of the current branch. For example, if you are on the - branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'. +'@\{\}', e.g. '@\{1\}':: + You can use the '@' construct with an empty ref part to get at a + reflog entry of the current branch. For example, if you are on + branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'. -* The special construct '@\{-\}' means the th branch checked out +'@\{-\}', e.g. '@\{-1\}':: + The construct '@\{-\}' means the th branch checked out before the current one. -* The suffix '@\{upstream\}' to a ref (short form 'ref@\{u\}') refers to - the branch the ref is set to build on top of. Missing ref defaults +'@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}':: + The suffix '@\{upstream\}' to a ref (short form '@\{u\}') refers to + the branch the ref is set to build on top of. A missing ref defaults to the current branch. -* A suffix '{caret}' to a revision parameter (e.g. 'HEAD{caret}') means the first parent of +'{caret}', e.g. 'HEAD{caret}, v1.5.1{caret}0':: + A suffix '{caret}' to a revision parameter means the first parent of that commit object. '{caret}' means the th parent (i.e. - 'rev{caret}' - is equivalent to 'rev{caret}1'). As a special rule, - 'rev{caret}0' means the commit itself and is used when 'rev' is the + '{caret}' + is equivalent to '{caret}1'). As a special rule, + '{caret}0' means the commit itself and is used when '' is the object name of a tag object that refers to a commit object. -* A suffix '{tilde}' to a revision parameter means the commit +'{tilde}', e.g. 'master{tilde}3':: + A suffix '{tilde}' to a revision parameter means the commit object that is the th generation grand-parent of the named - commit object, following only the first parent. I.e. rev~3 is - equivalent to rev{caret}{caret}{caret} which is equivalent to - rev{caret}1{caret}1{caret}1. See below for a illustration of + commit object, following only the first parents. I.e. '{tilde}3' is + equivalent to '{caret}{caret}{caret}' which is equivalent to + '{caret}1{caret}1{caret}1'. See below for an illustration of the usage of this form. -* A suffix '{caret}' followed by an object type name enclosed in - brace pair (e.g. 'v0.99.8{caret}\{commit\}') means the object +'{caret}\{\}', e.g. 'v0.99.8{caret}\{commit\}':: + A suffix '{caret}' followed by an object type name enclosed in + brace pair means the object could be a tag, and dereference the tag recursively until an object of that type is found or the object cannot be - dereferenced anymore (in which case, barf). 'rev{caret}0' - introduced earlier is a short-hand for 'rev{caret}\{commit\}'. + dereferenced anymore (in which case, barf). '{caret}0' + is a short-hand for '{caret}\{commit\}'. -* A suffix '{caret}' followed by an empty brace pair - (e.g. 'v0.99.8{caret}\{\}') means the object could be a tag, +'{caret}\{\}', e.g. 'v0.99.8{caret}\{\}':: + A suffix '{caret}' followed by an empty brace pair + means the object could be a tag, and dereference the tag recursively until a non-tag object is found. -* A suffix '{caret}' to a revision parameter followed by a brace - pair that contains a text led by a slash (e.g. 'HEAD^{/fix nasty bug}'): - this is the same as ':/fix nasty bug' syntax below except that +'{caret}\{/\}', e.g. 'HEAD^{/fix nasty bug}':: + A suffix '{caret}' to a revision parameter, followed by a brace + pair that contains a text led by a slash, + is the same as the ':/fix nasty bug' syntax below except that it returns the youngest matching commit which is reachable from - the ref before '{caret}'. + the '' before '{caret}'. -* A colon, followed by a slash, followed by a text (e.g. ':/fix nasty bug'): this names +':/', e.g. ':/fix nasty bug':: + A colon, followed by a slash, followed by a text, names a commit whose commit message matches the specified regular expression. This name returns the youngest matching commit which is reachable from any ref. If the commit message starts with a - '!', you have to repeat that; the special sequence ':/!', - followed by something else than '!' is reserved for now. + '!' you have to repeat that; the special sequence ':/!', + followed by something else than '!', is reserved for now. The regular expression can match any part of the commit message. To match messages starting with a string, one can use e.g. ':/^foo'. -* A suffix ':' followed by a path (e.g. 'HEAD:README'); this names the blob or tree +':', e.g. 'HEAD:README', ':README', 'master:./README':: + A suffix ':' followed by a path names the blob or tree at the given path in the tree-ish object named by the part before the colon. - ':path' (with an empty part before the colon, e.g. ':README') + ':path' (with an empty part before the colon) is a special case of the syntax described next: content recorded in the index at the given path. - A path starting with './' or '../' is relative to current working directory. - The given path will be converted to be relative to working tree's root directory. + A path starting with './' or '../' is relative to the current working directory. + The given path will be converted to be relative to the working tree's root directory. This is most useful to address a blob or tree from a commit or tree that has - the same tree structure with the working tree. + the same tree structure as the working tree. -* A colon, optionally followed by a stage number (0 to 3) and a - colon, followed by a path (e.g. ':0:README'); this names a blob object in the - index at the given path. Missing stage number (and the colon - that follows it, e.g. ':README') names a stage 0 entry. During a merge, stage +'::', e.g. ':0:README', ':README':: + A colon, optionally followed by a stage number (0 to 3) and a + colon, followed by a path, names a blob object in the + index at the given path. A missing stage number (and the colon + that follows it) names a stage 0 entry. During a merge, stage 1 is the common ancestor, stage 2 is the target branch's version (typically the current branch), and stage 3 is the version from - the branch being merged. + the branch which is being merged. Here is an illustration, by Jon Loeliger. Both commit nodes B and C are parents of commit node A. Parent commits are ordered