Differences

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--- git_revisions [2018/05/24 10:57] – created rpjday
+++ git_revisions [2019/03/18 11:45] (current) – [Commits with more than one parent] rpjday
@@ Line 1: / Line 1: @@
 ===== Overview =====
- A small sample of Git revisions; different ways to refer to commits (using Linux kernel source):
+ A small sample of Git revisions; different ways to refer to commits (using Linux kernel source repo).
 ===== Basic Git revisions =====
@@ Line 19: / Line 19: @@
 </code>
-And of course you can always use the full commit ID:
+And of course you can always use the full commit ID (or a sufficient prefix):
 <code>
 $ git show 0adb32858b0bddf4ada5f364a84ed60b196dbcda
+$ git show 0adb32858b0
 </code>
-You can use ''git rev-p
+You can use ''git rev-parse'' to map a reference to its underlying commit ID:
+<code>
+$ git rev-parse v4.16
+fb78e8be9d9428fbc4c016f8b031b01a6fdd63d
+$
+</code>
+===== Ancestral Git revisions/references =====
+Given any revision, you can refer to its (first) parent, or first grandparent, and so on:
+<code>
+$ git show HEAD
+$ git show HEAD^         (first parent)
+$ git show HEAD^^        (first grandparent)
+$ git show master^       (master's first parent)
+$ git show v4.16^^^      (v4.16's first great-grandparent)
+</code>
+There's also the //tilde// notation for brevity, so these are (ignoring intermediate merge commits) equivalent:
+<code>
+$ git show v4.16^^^
+$ git show v4.16~3
+</code>
+Examples using ''git diff'':
+<code>
+$ git diff v4.16^^ v4.16^
+$ git diff v4.16^ v4.16
+</code>
+===== Commits with more than one parent =====
+First or second parent:
+<code>
+$ git show HEAD^
+$ git show HEAD^2
+</code>
+Getting carried away:
+<code>
+$ git show v4.19^2~3^^
+</code>