envget varname
varname
The environment variable whose value is to be returned.
Envget returns the string value of the named environment variable. The user is prompted for the value if the variable has not yet been defined.
1. Construct a filename using the value of the environment variable "editor", and page the file thus named.
cl> page ("dev$" // envget ("editor") // ".ed")
2. Compute and print the center line on the terminal screen.
cl> = ((int (envget ("ttynlines")) + 1) / 2)