From 3a45f625aef0074a41885f1df335844ec8c04f5e Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Sun, 18 Sep 2005 11:13:58 -0700 Subject: Document extended SHA1 used by git-rev-parse. Signed-off-by: Junio C Hamano diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt index fa64c5a..5c136e0 100644 --- a/Documentation/git-rev-parse.txt +++ b/Documentation/git-rev-parse.txt @@ -76,6 +76,40 @@ OPTIONS Flags and parameters to be parsed. +SPECIFYING REVISIONS +-------------------- + +A revision parameter typically names a commit object. They use +what is called an 'extended SHA1' syntax. + +* 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. + +* A symbolic ref name. E.g. 'master' typically means the commit + object referenced by $GIT_DIR/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. + +* A suffix '^' to a revision parameter means the first parent of + that commit object. '^' means the th parent (i.e. 'rev^' + is equivalent to 'rev^1'). As a special rule, + 'rev^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 '~' to a revision parameter means the commit + object that is the th generation grand-parent of the named + commit object, following only the first parent. I.e. rev~3 is + equivalent to rev^^^ which is equivalent to rev^1^1^1. + +'git-rev-parse' also accepts a prefix '^' to revision parameter, +which is passed to 'git-rev-list'. Two revision parameters +concatenated with '..' is a short-hand for writing a range +between them. I.e. 'r1..r2' is equivalent to saying '^r1 r2' + + Author ------ Written by Linus Torvalds and -- cgit v0.10.2-6-g49f6