diff options
Diffstat (limited to 'Documentation/revisions.txt')
| -rw-r--r-- | Documentation/revisions.txt | 97 |
1 files changed, 78 insertions, 19 deletions
diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt index b290b617d4..07961185fe 100644 --- a/Documentation/revisions.txt +++ b/Documentation/revisions.txt @@ -2,13 +2,13 @@ SPECIFYING REVISIONS -------------------- A revision parameter '<rev>' typically, but not necessarily, names a -commit object. It uses what is called an 'extended SHA1' +commit object. It uses what is called an 'extended SHA-1' syntax. Here are various ways to spell object names. The ones listed near the end of this list name trees and blobs contained in a commit. '<sha1>', e.g. 'dae86e1950b1277e545cee180551750029cfe735', 'dae86e':: - The full SHA1 object name (40-byte hexadecimal string), or + The full SHA-1 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 is no other object in @@ -23,23 +23,23 @@ blobs contained in a commit. 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 '<name>' is disambiguated by taking the + explicitly say 'heads/master' to tell Git which one you mean. + When ambiguous, a '<refname>' is disambiguated by taking the first match in the following rules: - . If '$GIT_DIR/<name>' exists, that is what you mean (this is usually + . If '$GIT_DIR/<refname>' 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/<name>' if it exists; + . otherwise, 'refs/<refname>' if it exists; . otherwise, 'refs/tags/<refname>' if it exists; - . otherwise, 'refs/heads/<name>' if it exists; + . otherwise, 'refs/heads/<refname>' if it exists; - . otherwise, 'refs/remotes/<name>' if it exists; + . otherwise, 'refs/remotes/<refname>' if it exists; - . otherwise, 'refs/remotes/<name>/HEAD' if it exists. + . otherwise, 'refs/remotes/<refname>/HEAD' if it exists. + '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 @@ -55,6 +55,11 @@ 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. +While the ref name encoding is unspecified, UTF-8 is preferred as +some output processing may assume ref names in UTF-8. + +'@':: + '@' alone is a shortcut for 'HEAD'. '<refname>@\{<date>\}', e.g. 'master@\{yesterday\}', 'HEAD@\{5 minutes ago\}':: A ref followed by the suffix '@' with a date specification @@ -83,13 +88,15 @@ the '$GIT_DIR/refs' directory or from the '$GIT_DIR/packed-refs' file. branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'. '@\{-<n>\}', e.g. '@\{-1\}':: - The construct '@\{-<n>\}' means the <n>th branch checked out + The construct '@\{-<n>\}' means the <n>th branch/commit checked out before the current one. -'<refname>@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}':: - The suffix '@\{upstream\}' to a ref (short form '<refname>@\{u\}') refers to - the branch the ref is set to build on top of. A missing ref defaults - to the current branch. +'<branchname>@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}':: + The suffix '@\{upstream\}' to a branchname (short form '<branchname>@\{u\}') + refers to the branch that the branch specified by branchname is set to build on + top of (configured with `branch.<name>.remote` and + `branch.<name>.merge`). A missing branchname defaults to the + current one. '<rev>{caret}', e.g. 'HEAD{caret}, v1.5.1{caret}0':: A suffix '{caret}' to a revision parameter means the first parent of @@ -101,7 +108,7 @@ the '$GIT_DIR/refs' directory or from the '$GIT_DIR/packed-refs' file. '<rev>{tilde}<n>', e.g. 'master{tilde}3':: A suffix '{tilde}<n>' to a revision parameter means the commit - object that is the <n>th generation grand-parent of the named + object that is the <n>th generation ancestor of the named commit object, following only the first parents. I.e. '<rev>{tilde}3' is equivalent to '<rev>{caret}{caret}{caret}' which is equivalent to '<rev>{caret}1{caret}1{caret}1'. See below for an illustration of @@ -109,11 +116,23 @@ the '$GIT_DIR/refs' directory or from the '$GIT_DIR/packed-refs' file. '<rev>{caret}\{<type>\}', 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' + brace pair means dereference the object at '<rev>' recursively until + an object of type '<type>' is found or the object cannot be + dereferenced anymore (in which case, barf). + For example, if '<rev>' is a commit-ish, '<rev>{caret}\{commit\}' + describes the corresponding commit object. + Similarly, if '<rev>' is a tree-ish, '<rev>{caret}\{tree\}' + describes the corresponding tree object. + '<rev>{caret}0' is a short-hand for '<rev>{caret}\{commit\}'. ++ +'rev{caret}\{object\}' can be used to make sure 'rev' names an +object that exists, without requiring 'rev' to be a tag, and +without dereferencing 'rev'; because a tag is already an object, +it does not have to be dereferenced even once to get to an object. ++ +'rev{caret}\{tag\}' can be used to ensure that 'rev' identifies an +existing tag object. '<rev>{caret}\{\}', e.g. 'v0.99.8{caret}\{\}':: A suffix '{caret}' followed by an empty brace pair @@ -213,18 +232,58 @@ of 'r1' and 'r2' and is defined as It is the set of commits that are reachable from either one of 'r1' or 'r2' but not from both. +In these two shorthands, you can omit one end and let it default to HEAD. +For example, 'origin..' is a shorthand for 'origin..HEAD' and asks "What +did I do since I forked from the origin branch?" Similarly, '..origin' +is a shorthand for 'HEAD..origin' and asks "What did the origin do since +I forked from them?" Note that '..' would mean 'HEAD..HEAD' which is an +empty range that is both reachable and unreachable from HEAD. + Two other shorthands for naming a set that is formed by a commit and its parent commits exist. The 'r1{caret}@' notation means all parents of 'r1'. 'r1{caret}!' includes commit 'r1' but excludes all of its parents. +To summarize: + +'<rev>':: + Include commits that are reachable from (i.e. ancestors of) + <rev>. + +'{caret}<rev>':: + Exclude commits that are reachable from (i.e. ancestors of) + <rev>. + +'<rev1>..<rev2>':: + Include commits that are reachable from <rev2> but exclude + those that are reachable from <rev1>. When either <rev1> or + <rev2> is omitted, it defaults to 'HEAD'. + +'<rev1>\...<rev2>':: + Include commits that are reachable from either <rev1> or + <rev2> but exclude those that are reachable from both. When + either <rev1> or <rev2> is omitted, it defaults to 'HEAD'. + +'<rev>{caret}@', e.g. 'HEAD{caret}@':: + A suffix '{caret}' followed by an at sign is the same as listing + all parents of '<rev>' (meaning, include anything reachable from + its parents, but not the commit itself). + +'<rev>{caret}!', e.g. 'HEAD{caret}!':: + A suffix '{caret}' followed by an exclamation mark is the same + as giving commit '<rev>' and then all its parents prefixed with + '{caret}' to exclude them (and their ancestors). + Here are a handful of examples: D G H D D F G H I J D F ^G D H D ^D B E I J F B + B..C C B...C G H D E B C ^D B C E I J F B C + C I J F C C^@ I J F + C^! C F^! D G H D F |