![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
index 627cde8520830c76378ffff0f2cc5cdc92fe2483..4eaf5a0d1ea26798298c4f572c29d90af9dc7cf1 100644 (file)
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. They use what is called an 'extended SHA1'
-syntax.
+syntax. Here are various ways to spell object names. The
+ones listed near the end of this list are to 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.
* The full SHA1 object name (40-byte hexadecimal string), or
a substring of such that is unique within the repository.
name the same commit object if there are no other object in
your repository whose object name starts with dae86e.
name the same commit object if there are no other object in
your repository whose object name starts with dae86e.
+* An output from `git-describe`; i.e. a closest tag, followed by a
+ dash, a `g`, and an abbreviated object name.
+
* A symbolic ref name. E.g. 'master' typically means the commit
object referenced by $GIT_DIR/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.
* A symbolic ref name. E.g. 'master' typically means the commit
object referenced by $GIT_DIR/refs/heads/master. If you
happen to have both heads/master and tags/master, you can
explicitly say 'heads/master' to tell git which one you mean.
+ When ambiguous, a `<name>` is disambiguated by taking the
+ first match in the following rules:
+
+ . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
+ useful only for `HEAD`, `FETCH_HEAD` and `MERGE_HEAD`);
+
+ . otherwise, `$GIT_DIR/refs/<name>` if exists;
+
+ . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
+
+ . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
-* A suffix '@' followed by a date specification enclosed in a brace
+ . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
+
+ . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
+
+* 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
of the ref at a prior point in time. This suffix may only be
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
of the ref at a prior point in time. This suffix may only be
'rev{caret}0' means the commit itself and is used when 'rev' is the
object name of a tag object that refers to a commit object.
'rev{caret}0' means the commit itself and is used when 'rev' is the
object name of a tag object that refers to a commit object.
-* A suffix '~<n>' to a revision parameter means the commit
+* A suffix '{tilde}<n>' to a revision parameter means the commit
object that is the <n>th generation grand-parent of the named
commit object, following only the first parent. I.e. rev~3 is
object that is the <n>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.
+ equivalent to rev{caret}{caret}{caret} which is equivalent to
+ rev{caret}1{caret}1{caret}1. See below for a 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
* A suffix '{caret}' followed by an object type name enclosed in
brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
and dereference the tag recursively until a non-tag object is
found.
and dereference the tag recursively until a non-tag object is
found.
-'git-rev-parse' also accepts a prefix '{caret}' to revision parameter,
-which is passed to 'git-rev-list'. Two revision parameters
-concatenated with '..' is a short-hand for writing a range
-between them. I.e. 'r1..r2' is equivalent to saying '{caret}r1 r2'
+* A suffix ':' followed by a path; this names the blob or tree
+ at the given path in the tree-ish object named by the part
+ before the colon.
+
+* A colon, optionally followed by a stage number (0 to 3) and a
+ colon, followed by a path; this names a blob object in the
+ index at the given path. Missing stage number (and the colon
+ that follows it) names an stage 0 entry.
Here is an illustration, by Jon Loeliger. Both node B and C are
a commit parents of commit node A. Parent commits are ordered
Here is an illustration, by Jon Loeliger. Both node B and C are
a commit parents of commit node A. Parent commits are ordered
G H I J
\ / \ /
D E F
G H I J
\ / \ /
D E F
- \ | /
- \ | /
- \|/
+ \ | / \
+ \ | / |
+ \|/ |
B C
\ /
\ /
B C
\ /
\ /
J = F^2 = B^3^2 = A^^3^2
J = F^2 = B^3^2 = A^^3^2
+SPECIFYING RANGES
+-----------------
+
+History traversing commands such as `git-log` operate on a set
+of commits, not just a single commit. To these commands,
+specifying a single revision with the notation described in the
+previous section means the set of commits reachable from that
+commit, following the commit ancestry chain.
+
+To exclude commits reachable from a commit, a prefix `{caret}`
+notation is used. E.g. "`{caret}r1 r2`" means commits reachable
+from `r2` but exclude the ones reachable from `r1`.
+
+This set operation appears so often that there is a shorthand
+for it. "`r1..r2`" is equivalent to "`{caret}r1 r2`". It is
+the difference of two sets (subtract the set of commits
+reachable from `r1` from the set of commits reachable from
+`r2`).
+
+A similar notation "`r1\...r2`" is called symmetric difference
+of `r1` and `r2` and is defined as
+"`r1 r2 --not $(git-merge-base --all r1 r2)`".
+It it the set of commits that are reachable from either one of
+`r1` or `r2` but not from both.
+
+Two other shorthands for naming a set that is formed by a commit
+and its parent commits exists. `r1{caret}@` notation means all
+parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
+its all parents.
+
+Here are a handful examples:
+
+ D A B D
+ D F A B C D F
+ ^A G B D
+ ^A F B C F
+ G...I C D F G I
+ ^B G I C D F G I
+ F^@ A B C
+ F^! H D F H
+
Author
------
Written by Linus Torvalds <torvalds@osdl.org> and
Author
------
Written by Linus Torvalds <torvalds@osdl.org> and