Gnu/coreutils/printenv-invocation

From Get docs

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 program accepts the following option. Also see Common options.

-0
--null

Output a zero byte (ASCII NUL) at the end of each line, rather than a newline. This option enables other programs to parse the output even when that output would contain data with embedded newlines.

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