### 3.10 `rmdel`

The `rmdel` (“Remove Delta”) command allows the last version last checked in to an SCCS file to be removed again. Typically, one does this after realizing that newly checked in version doesn’t compile, or doesn’t work, and the fix is simple. In the author’s opinion, it’s almost always better to be honest about mistakes, and just make a new delta for the fixed version.

The SID of a removed delta is soon re-used by `delta`, usually for the fixed version.

The `rmdel` command takes only one option, `-r`, which specifies the SID of the version to be removed. This option is mandatory.

The `rmdel` command will fail if you hadn’t checked in that revision, or if it is in use in some way. For example, `rmdel` fails if the specified SID is not the latest revision on its branch, or if it has been checked out for editing.

As usual, any number of SCCS files can be named on the command line. The special argument `-` indicates that the list of files to be operated on should be read from standard input. If an argument is a directory, the RMDEL command is applied to all SCCS files in that directory.