19.3 printenv: Print all or some environment variables

printenv prints environment variable values. Synopsis:

printenv [option] [variable]...

If no variables are specified, printenv prints the value of every environment variable. Otherwise, it prints the value of each variable that is set, and nothing for those that are not set.

The only options are a lone `--help' or `--version'. See section 2. Common options.

Exit status:

0 if all variables specified were found 1 if at least one specified variable was not found 2 if a write error occurred