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Diffstat (limited to 'Documentation/git-update-ref.txt')
| -rw-r--r-- | Documentation/git-update-ref.txt | 53 |
1 files changed, 43 insertions, 10 deletions
diff --git a/Documentation/git-update-ref.txt b/Documentation/git-update-ref.txt index 475237f19e..d377a35243 100644 --- a/Documentation/git-update-ref.txt +++ b/Documentation/git-update-ref.txt @@ -3,24 +3,27 @@ git-update-ref(1) NAME ---- -git-update-ref - update the object name stored in a ref safely +git-update-ref - Update the object name stored in a ref safely SYNOPSIS -------- -'git-update-ref' <ref> <newvalue> [<oldvalue>] +[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 +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>` +E.g. `git update-ref refs/heads/master <newvalue> <oldvalue>` updates the master branch head to <newvalue> only if its current -value is <oldvalue>. +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 @@ -34,9 +37,12 @@ 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 "$head" + git update-ref HEAD "$head" should be a _lot_ safer than doing @@ -49,10 +55,37 @@ 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). -Author ------- -Written by Linus Torvalds <torvalds@osdl.org>. +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 gitlink:git[7] suite +Part of the linkgit:git[1] suite |