Specifying Git revisionsEdit

There are many, many ways of specifying revisions in Git which are described in detail in the git-rev-parse man page. This article summarizes some of the more useful ones:

Accessing parents of a commit

Given a commit, rev:

• rev^ is the first parent (remember that a commit can have multiple parents)
• rev^1 is the more explicit form of referring to the first parent
• rev^2 would refer to the second parent (not the grand-parent, but the second parent, such as in cases where you have two parents that are merged to produce a new commit).
• rev^0 is the commit itself
• rev^^ is the first grandparent (first parent of first parent)
• rev^1^1 is equivalent
• rev^^2 is a different grandparent (second parent of first parent)
• rev^1^2 alternative form of the same
• rev^2^2 second parent of second parent
• rev^2^1 first parent of second parent
• rev^2^ alternative form of the same
• rev~1 is another way of referring to the first parent
• rev~2 is another way of referring to the first grandparent (first parent of first parent)
• rev~3 is another way of referring to the first great-grandparent (first parent of first parent of first parent)

Putting all this together means that you can make some downright hideous references; for example:

• maint~52^2^2~5: refers to a distant ancestor of the HEAD of the maint branch; specifically, the 52nd generation grandparent’s second parent’s second parent’s 5th generation grandparent.

Accessing prior values of a ref

• ref@{1} is the immediate prior value of a ref (for example, master@{1})
• ref@{2} is the second prior value, and so on
• @{2} would refer to the same thing if you were already on branch ref