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Diffstat (limited to 'Documentation/git-update-ref.txt')
| -rw-r--r-- | Documentation/git-update-ref.txt | 80 |
1 files changed, 68 insertions, 12 deletions
diff --git a/Documentation/git-update-ref.txt b/Documentation/git-update-ref.txt index f222616591..c8f5ae5cb3 100644 --- a/Documentation/git-update-ref.txt +++ b/Documentation/git-update-ref.txt @@ -7,18 +7,19 @@ git-update-ref - Update the object name stored in a ref safely SYNOPSIS -------- -'git-update-ref' [-m <reason>] (-d <ref> <oldvalue> | [--no-deref] <ref> <newvalue> [<oldvalue>]) +[verse] +'git update-ref' [-m <reason>] (-d <ref> [<oldvalue>] | [--no-deref] <ref> <newvalue> [<oldvalue>] | --stdin [-z]) 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>. You can specify 40 "0" or an empty string as <oldvalue> to make sure that the ref you are creating does @@ -41,7 +42,7 @@ 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 @@ -57,11 +58,70 @@ archive by creating a symlink tree). With `-d` flag, it deletes the named <ref> after verifying it still contains <oldvalue>. +With `--stdin`, update-ref reads instructions from standard input and +performs all modifications together. Specify commands of the form: + + update SP <ref> SP <newvalue> [SP <oldvalue>] LF + create SP <ref> SP <newvalue> LF + delete SP <ref> [SP <oldvalue>] LF + verify SP <ref> [SP <oldvalue>] LF + option SP <opt> LF + +Quote fields containing whitespace as if they were strings in C source +code; i.e., surrounded by double-quotes and with backslash escapes. +Use 40 "0" characters or the empty string to specify a zero value. To +specify a missing value, omit the value and its preceding SP entirely. + +Alternatively, use `-z` to specify in NUL-terminated format, without +quoting: + + update SP <ref> NUL <newvalue> NUL [<oldvalue>] NUL + create SP <ref> NUL <newvalue> NUL + delete SP <ref> NUL [<oldvalue>] NUL + verify SP <ref> NUL [<oldvalue>] NUL + option SP <opt> NUL + +In this format, use 40 "0" to specify a zero value, and use the empty +string to specify a missing value. + +In either format, values can be specified in any form that Git +recognizes as an object name. Commands in any other format or a +repeated <ref> produce an error. Command meanings are: + +update:: + Set <ref> to <newvalue> after verifying <oldvalue>, if given. + Specify a zero <newvalue> to ensure the ref does not exist + after the update and/or a zero <oldvalue> to make sure the + ref does not exist before the update. + +create:: + Create <ref> with <newvalue> after verifying it does not + exist. The given <newvalue> may not be zero. + +delete:: + Delete <ref> after verifying it exists with <oldvalue>, if + given. If given, <oldvalue> may not be zero. + +verify:: + Verify <ref> against <oldvalue> but do not change it. If + <oldvalue> zero or missing, the ref must not exist. + +option:: + Modify behavior of the next command naming a <ref>. + The only valid option is `no-deref` to avoid dereferencing + a symbolic ref. + +If all <ref>s can be locked with matching <oldvalue>s +simultaneously, all modifications are performed. Otherwise, no +modifications are performed. Note that while each individual +<ref> is updated or deleted atomically, a concurrent reader may +still see a subset of the modifications. Logging Updates --------------- -If config parameter "core.logAllRefUpdates" is true or the file -"$GIT_DIR/logs/<ref>" exists then `git-update-ref` will append +If config parameter "core.logAllRefUpdates" is true and the ref is one under +"refs/heads/", "refs/remotes/", "refs/notes/", or the symbolic ref HEAD; or +the file "$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: @@ -71,7 +131,7 @@ in ref value. Log lines are formatted as: 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. +and date in the standard Git committer ident format. Optionally with -m: @@ -84,10 +144,6 @@ 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. -Author ------- -Written by Linus Torvalds <torvalds@osdl.org>. - GIT --- -Part of the gitlink:git[7] suite +Part of the linkgit:git[1] suite |