| PRINTENV(1) | General Commands Manual | PRINTENV(1) | 
printenv —
| printenv | [name] | 
printenv prints out the names and values of the
  variables in the environment, with one name/value pair per line. If
  name is specified, only its value is printed.
If a name is specified and it is not defined
    in the environment, printenv returns exit status 1,
    else it returns status 0.
printenv command appeared in
  3.0BSD.
| June 6, 1993 | NetBSD 10.1 |