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-rw-r--r--Documentation/revisions.txt218
1 files changed, 147 insertions, 71 deletions
diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt
index 07961185fe..ba11b9c95e 100644
--- a/Documentation/revisions.txt
+++ b/Documentation/revisions.txt
@@ -28,8 +28,8 @@ blobs contained in a commit.
first match in the following rules:
. 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');
+ useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD`, `MERGE_HEAD`
+ and `CHERRY_PICK_HEAD`);
. otherwise, 'refs/<refname>' if it exists;
@@ -41,16 +41,16 @@ blobs contained in a commit.
. 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
+`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 move your 'HEAD' in a drastic
-way, to record the position of the 'HEAD' before their operation, so that
+`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 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
+`MERGE_HEAD` records the commit(s) which you are merging into your branch
when you run `git merge`.
-'CHERRY_PICK_HEAD' records the commit which 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
@@ -59,21 +59,21 @@ 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'.
+ '@' alone is a shortcut for `HEAD`.
-'<refname>@\{<date>\}', e.g. 'master@\{yesterday\}', 'HEAD@\{5 minutes ago\}'::
+'<refname>@{<date>}', 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\}') specifies the value
+ pair (e.g. '\{yesterday\}', '{1 month 2 weeks 3 days 1 hour 1
+ 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/<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'.
+ certain times, see `--since` and `--until`.
-'<refname>@\{<n>\}', e.g. 'master@\{1\}'::
+'<refname>@{<n>}', 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\}'
@@ -82,13 +82,13 @@ some output processing may assume ref names in UTF-8.
immediately following a ref name and the ref must have an existing
log ('$GIT_DIR/logs/<refname>').
-'@\{<n>\}', e.g. '@\{1\}'::
+'@{<n>}', e.g. '@\{1\}'::
You can use the '@' construct with an empty ref part to get at a
reflog entry of the current branch. For example, if you are on
branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'.
-'@\{-<n>\}', e.g. '@\{-1\}'::
- The construct '@\{-<n>\}' means the <n>th branch/commit checked out
+'@{-<n>}', e.g. '@{-1}'::
+ The construct '@{-<n>}' means the <n>th branch/commit checked out
before the current one.
'<branchname>@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}'::
@@ -98,6 +98,31 @@ some output processing may assume ref names in UTF-8.
`branch.<name>.merge`). A missing branchname defaults to the
current one.
+'<branchname>@\{push\}', e.g. 'master@\{push\}', '@\{push\}'::
+ The suffix '@\{push}' reports the branch "where we would push to" if
+ `git push` were run while `branchname` was checked out (or the current
+ `HEAD` if no branchname is specified). Since our push destination is
+ in a remote repository, of course, we report the local tracking branch
+ that corresponds to that branch (i.e., something in 'refs/remotes/').
++
+Here's an example to make it more clear:
++
+------------------------------
+$ git config push.default current
+$ git config remote.pushdefault myfork
+$ git checkout -b mybranch origin/master
+
+$ git rev-parse --symbolic-full-name @{upstream}
+refs/remotes/origin/master
+
+$ git rev-parse --symbolic-full-name @{push}
+refs/remotes/myfork/mybranch
+------------------------------
++
+Note in the example that we set up a triangular workflow, where we pull
+from one location and push to another. In a non-triangular workflow,
+'@\{push}' is the same as '@\{upstream}', and there is no need for it.
+
'<rev>{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}<n>' means the <n>th parent (i.e.
@@ -114,7 +139,7 @@ some output processing may assume ref names in UTF-8.
'<rev>{caret}1{caret}1{caret}1'. See below for an illustration of
the usage of this form.
-'<rev>{caret}\{<type>\}', e.g. 'v0.99.8{caret}\{commit\}'::
+'<rev>{caret}{<type>}', e.g. 'v0.99.8{caret}\{commit\}'::
A suffix '{caret}' followed by an object type name enclosed in
brace pair means dereference the object at '<rev>' recursively until
an object of type '<type>' is found or the object cannot be
@@ -134,13 +159,13 @@ 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}\{\}'::
+'<rev>{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.
-'<rev>{caret}\{/<text>\}', e.g. 'HEAD^{/fix nasty bug}'::
+'<rev>{caret}{/<text>}', 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
@@ -151,11 +176,12 @@ existing tag object.
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.
- The regular expression can match any part of the commit message. To
- match messages starting with a string, one can use e.g. ':/^foo'.
+ reachable from any ref. The regular expression can match any part of the
+ commit message. To match messages starting with a string, one can use
+ e.g. ':/^foo'. The special sequence ':/!' is reserved for modifiers to what
+ is matched. ':/!-foo' performs a negative match, while ':/!!foo' matches a
+ literal '!' character, followed by 'foo'. Any other sequence beginning with
+ ':/!' is reserved for now.
'<rev>:<path>', e.g. 'HEAD:README', ':README', 'master:./README'::
A suffix ':' followed by a path names the blob or tree
@@ -211,58 +237,91 @@ 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.
-
-In these two shorthands, you can omit one end and let it default to HEAD.
+of commits, not just a single commit.
+
+For these commands,
+specifying a single revision, using the notation described in the
+previous section, means the set of commits `reachable` from the given
+commit.
+
+A commit's reachable set is the commit itself and the commits in
+its ancestry chain.
+
+
+Commit Exclusions
+~~~~~~~~~~~~~~~~~
+
+'{caret}<rev>' (caret) Notation::
+ 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' (i.e. 'r1' and
+ its ancestors).
+
+Dotted Range Notations
+~~~~~~~~~~~~~~~~~~~~~~
+
+The '..' (two-dot) Range Notation::
+ The '{caret}r1 r2' 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'.
+
+The '...' (three dot) Symmetric Difference Notation::
+ 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' (left side) or 'r2' (right side) but not from both.
+
+In these two shorthand notations, 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.
+Other <rev>{caret} Parent Shorthand Notations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Three other shorthands exist, particularly useful for merge commits,
+for naming a set that is formed by a commit and its parent commits.
+
+The 'r1{caret}@' notation means all parents of 'r1'.
+
+The 'r1{caret}!' notation includes commit 'r1' but excludes all of its parents.
+By itself, this notation denotes the single commit 'r1'.
+
+The '<rev>{caret}-{<n>}' notation includes '<rev>' but excludes the <n>th
+parent (i.e. a shorthand for '<rev>{caret}<n>..<rev>'), with '<n>' = 1 if
+not given. This is typically useful for merge commits where you
+can just pass '<commit>{caret}-' to get all the commits in the branch
+that was merged in merge commit '<commit>' (including '<commit>'
+itself).
+
+While '<rev>{caret}<n>' was about specifying a single commit parent, these
+three notations also consider its parents. For example you can say
+'HEAD{caret}2{caret}@', however you cannot say 'HEAD{caret}@{caret}2'.
-To summarize:
+Revision Range Summary
+----------------------
'<rev>'::
- Include commits that are reachable from (i.e. ancestors of)
- <rev>.
+ Include commits that are reachable from <rev> (i.e. <rev> and its
+ ancestors).
'{caret}<rev>'::
- Exclude commits that are reachable from (i.e. ancestors of)
- <rev>.
+ Exclude commits that are reachable from <rev> (i.e. <rev> and its
+ ancestors).
'<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'.
+ <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'.
+ 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
@@ -274,16 +333,33 @@ To summarize:
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
+'<rev>{caret}-{<n>}', e.g. 'HEAD{caret}-, HEAD{caret}-2'::
+ Equivalent to '<rev>{caret}<n>..<rev>', with '<n>' = 1 if not
+ given.
+
+Here are a handful of examples using the Loeliger illustration above,
+with each step in the notation's expansion and selection carefully
+spelt out:
+
+ Args Expanded arguments Selected commits
+ D G H D
+ D F G H I J D F
+ ^G D H D
+ ^D B E I J F B
+ ^D B C E I J F B C
+ C I J F C
+ B..C = ^B C C
+ B...C = B ^F C G H D E B C
+ B^- = B^..B
+ = ^B^1 B E I J F B
+ C^@ = C^1
+ = F I J F
+ B^@ = B^1 B^2 B^3
+ = D E F D G H E F I J
+ C^! = C ^C^@
+ = C ^C^1
+ = C ^F C
+ B^! = B ^B^@
+ = B ^B^1 ^B^2 ^B^3
+ = B ^D ^E ^F B
+ F^! D = F ^I ^J D G H D F