mirror of
https://github.com/git/git.git
synced 2024-11-18 15:04:49 +01:00
ef6663b3db
* bw/log-all-ref-updates-doc: Documentation: clearly specify what refs are honored by core.logAllRefUpdates
91 lines
3.2 KiB
Text
91 lines
3.2 KiB
Text
git-update-ref(1)
|
|
=================
|
|
|
|
NAME
|
|
----
|
|
git-update-ref - Update the object name stored in a ref safely
|
|
|
|
SYNOPSIS
|
|
--------
|
|
[verse]
|
|
'git update-ref' [-m <reason>] (-d <ref> [<oldvalue>] | [--no-deref] <ref> <newvalue> [<oldvalue>])
|
|
|
|
DESCRIPTION
|
|
-----------
|
|
Given two arguments, stores the <newvalue> in the <ref>, possibly
|
|
dereferencing the symbolic refs. E.g. `git update-ref HEAD
|
|
<newvalue>` updates the current branch head to the new object.
|
|
|
|
Given three arguments, stores the <newvalue> in the <ref>,
|
|
possibly dereferencing the symbolic refs, after verifying that
|
|
the current value of the <ref> matches <oldvalue>.
|
|
E.g. `git update-ref refs/heads/master <newvalue> <oldvalue>`
|
|
updates the master branch head to <newvalue> only if its current
|
|
value is <oldvalue>. You can specify 40 "0" or an empty string
|
|
as <oldvalue> to make sure that the ref you are creating does
|
|
not exist.
|
|
|
|
It also allows a "ref" file to be a symbolic pointer to another
|
|
ref file by starting with the four-byte header sequence of
|
|
"ref:".
|
|
|
|
More importantly, it allows the update of a ref file to follow
|
|
these symbolic pointers, whether they are symlinks or these
|
|
"regular file symbolic refs". It follows *real* symlinks only
|
|
if they start with "refs/": otherwise it will just try to read
|
|
them and update them as a regular file (i.e. it will allow the
|
|
filesystem to follow them, but will overwrite such a symlink to
|
|
somewhere else with a regular filename).
|
|
|
|
If --no-deref is given, <ref> itself is overwritten, rather than
|
|
the result of following the symbolic pointers.
|
|
|
|
In general, using
|
|
|
|
git update-ref HEAD "$head"
|
|
|
|
should be a _lot_ safer than doing
|
|
|
|
echo "$head" > "$GIT_DIR/HEAD"
|
|
|
|
both from a symlink following standpoint *and* an error checking
|
|
standpoint. The "refs/" rule for symlinks means that symlinks
|
|
that point to "outside" the tree are safe: they'll be followed
|
|
for reading but not for writing (so we'll never write through a
|
|
ref symlink to some other tree, if you have copied a whole
|
|
archive by creating a symlink tree).
|
|
|
|
With `-d` flag, it deletes the named <ref> after verifying it
|
|
still contains <oldvalue>.
|
|
|
|
|
|
Logging Updates
|
|
---------------
|
|
If config parameter "core.logAllRefUpdates" is true and the ref is one under
|
|
"refs/heads/", "refs/remotes/", "refs/notes/", or the symbolic ref HEAD; or
|
|
the file "$GIT_DIR/logs/<ref>" exists then `git update-ref` will append
|
|
a line to the log file "$GIT_DIR/logs/<ref>" (dereferencing all
|
|
symbolic refs before creating the log name) describing the change
|
|
in ref value. Log lines are formatted as:
|
|
|
|
. oldsha1 SP newsha1 SP committer LF
|
|
+
|
|
Where "oldsha1" is the 40 character hexadecimal value previously
|
|
stored in <ref>, "newsha1" is the 40 character hexadecimal value of
|
|
<newvalue> and "committer" is the committer's name, email address
|
|
and date in the standard GIT committer ident format.
|
|
|
|
Optionally with -m:
|
|
|
|
. oldsha1 SP newsha1 SP committer TAB message LF
|
|
+
|
|
Where all fields are as described above and "message" is the
|
|
value supplied to the -m option.
|
|
|
|
An update will fail (without changing <ref>) if the current user is
|
|
unable to create a new log file, append to the existing log file
|
|
or does not have committer information available.
|
|
|
|
GIT
|
|
---
|
|
Part of the linkgit:git[1] suite
|