View a stream as of a specific changelist

The StreamAtChange option in the client spec lets you use the version of the stream specified as of a particular changelist to generate a workspace view. This is helpful when you want to see what the stream view was at a particular point in time. This might useful if your stream spec changes frequently, such as changing what you are importing or what you are sharing.

When you use the StreamAtChange option, you cannot submit changes to the files in the stream because your workspace view is not up to date.

To set a stream workspace to use the version of the stream specified as of a particular changelist:

Open the stream’s workspace specification form for editing with the p4 client command.
```
$ p4 client
```
Edit the form to set StreamAtChange to the changelist you want. For example:
```
StreamAtChange: 12546
```

Alternatively, use the -S option of p4 client to specify the stream and change for the view:

$ p4 client -S //Ace/main@12546

or, use the p4 switch command to both set the StreamAtChange value and perform a sync to that change:

$ p4 switch -r -v //Ace/main@12546