mirror of
https://github.com/git/git.git
synced 2024-12-02 14:34:03 +08:00
41cd7974b0
* nd/oneline-sha1-name-from-specific-ref:
get_sha1: handle special case $commit^{/}
get_sha1: support $commit^{/regex} syntax
get_sha1_oneline: make callers prepare the commit list to traverse
get_sha1_oneline: fix lifespan rule of temp_commit_buffer variable
212 lines
8.8 KiB
Plaintext
212 lines
8.8 KiB
Plaintext
SPECIFYING REVISIONS
|
|
--------------------
|
|
|
|
A revision parameter typically, but not necessarily, names a
|
|
commit object. They use what is called an 'extended SHA1'
|
|
syntax. Here are various ways to spell object names. The
|
|
ones listed near the end of this list are to name trees and
|
|
blobs contained in a commit.
|
|
|
|
* The full SHA1 object name (40-byte hexadecimal string), or
|
|
a substring of such that is unique within the repository.
|
|
E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
|
|
name the same commit object if there are no other object in
|
|
your repository whose object name starts with dae86e.
|
|
|
|
* An output from 'git describe'; i.e. a closest tag, optionally
|
|
followed by a dash and a number of commits, followed by a dash, a
|
|
`g`, and an abbreviated object name.
|
|
|
|
* A symbolic ref name. E.g. 'master' typically means the commit
|
|
object referenced by refs/heads/master. If you
|
|
happen to have both heads/master and tags/master, you can
|
|
explicitly say 'heads/master' to tell git which one you mean.
|
|
When ambiguous, a `<name>` is disambiguated by taking the
|
|
first match in the following rules:
|
|
|
|
. if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
|
|
useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD` and `MERGE_HEAD`);
|
|
|
|
. otherwise, `refs/<name>` if exists;
|
|
|
|
. otherwise, `refs/tags/<name>` if exists;
|
|
|
|
. otherwise, `refs/heads/<name>` if exists;
|
|
|
|
. otherwise, `refs/remotes/<name>` if exists;
|
|
|
|
. otherwise, `refs/remotes/<name>/HEAD` if 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
|
|
with your last 'git fetch' invocation.
|
|
ORIG_HEAD is created by commands that moves 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
|
|
when you run 'git merge'.
|
|
+
|
|
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
|
|
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
|
|
used immediately following a ref name and the ref must have an
|
|
existing log ($GIT_DIR/logs/<ref>). Note that this looks up the state
|
|
of your *local* ref at a given time; e.g., what was in your local
|
|
`master` branch last week. If you want to look at commits made during
|
|
certain times, see `--since` and `--until`.
|
|
|
|
* A ref followed by the suffix '@' with an ordinal specification
|
|
enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
|
|
the n-th prior value of that ref. For example 'master@\{1\}'
|
|
is the immediate prior value of 'master' while 'master@\{5\}'
|
|
is the 5th prior value of 'master'. This suffix may only be used
|
|
immediately following a ref name and the ref must have an existing
|
|
log ($GIT_DIR/logs/<ref>).
|
|
|
|
* 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\}'.
|
|
|
|
* The special construct '@\{-<n>\}' means the <n>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
|
|
to the current branch.
|
|
|
|
* A suffix '{caret}' to a revision parameter (e.g. 'HEAD{caret}') means the first parent of
|
|
that commit object. '{caret}<n>' means the <n>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
|
|
object name of a tag object that refers to a commit object.
|
|
|
|
* 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
|
|
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
|
|
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\}`.
|
|
|
|
* A suffix '{caret}' followed by an empty brace pair
|
|
(e.g. `v0.99.8{caret}\{\}`) 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
|
|
it returns the youngest matching commit which is reachable from
|
|
the ref before '{caret}'.
|
|
|
|
* A colon, followed by a slash, followed by a text (e.g. `:/fix nasty bug`): this 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.
|
|
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
|
|
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`)
|
|
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.
|
|
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.
|
|
|
|
* 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
|
|
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.
|
|
|
|
Here is an illustration, by Jon Loeliger. Both commit nodes B
|
|
and C are parents of commit node A. Parent commits are ordered
|
|
left-to-right.
|
|
|
|
........................................
|
|
G H I J
|
|
\ / \ /
|
|
D E F
|
|
\ | / \
|
|
\ | / |
|
|
\|/ |
|
|
B C
|
|
\ /
|
|
\ /
|
|
A
|
|
........................................
|
|
|
|
A = = A^0
|
|
B = A^ = A^1 = A~1
|
|
C = A^2 = A^2
|
|
D = A^^ = A^1^1 = A~2
|
|
E = B^2 = A^^2
|
|
F = B^3 = A^^3
|
|
G = A^^^ = A^1^1^1 = A~3
|
|
H = D^2 = B^^2 = A^^^2 = A~2^2
|
|
I = F^ = B^3^ = A^^3^
|
|
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. When you have two commits `r1` and `r2` (named according
|
|
to the syntax explained in SPECIFYING REVISIONS above), you can ask
|
|
for commits that are reachable from r2 excluding those that are reachable
|
|
from r1 by `{caret}r1 r2` and it can be written as `r1..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 is 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 exist. The `r1{caret}@` notation means all
|
|
parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
|
|
all of its parents.
|
|
|
|
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 G H D E B C
|
|
^D B C E I J F B C
|
|
C^@ I J F
|
|
F^! D G H D F
|