clearlf - clear contents in an existing RMSfile
Clearlf removes the contents of an RMSfile. This utility is used when the contents of the RMSfile are no longer needed, but the RMSfile will be re-used (as in a scratch file). Once the contents of an RMSfile have been removed with clearlf they are no longer accessible to any program.
If the datafile argument has the form dbname~lfile or ~lfile, then clearlf clears the file using the database and logical file name. If the datafile argument has the form filename (i.e. it has neither a ~ nor / in the name), then it is taken as a logical file name using the default database name