env —
set and print environment
  
    | env | [ -i] [name=value ...]
      [utility [argument ...]] | 
env executes utility after
  modifying the environment as specified on the command line. The option
  name=value specifies an environmental variable,
  name, with a value of value. The
  option ‘-i’ causes
  env to completely ignore the environment it inherits.
If no utility is specified,
    env prints out the names and values of the variables
    in the environment, with one name=value pair per
  line.
env exits with one of the following values:
  - 0
- utility was invoked and completed successfully. In
      this case the exit code is returned by the utility itself, not
      env. If no utility was specified, thenenvcompleted successfully and returned the exit
      code itself.
- 1
- An invalid command line option was passed to
    env.
- 1-125
- utility was invoked, but failed in some way; see its
      manual page for more information. In this case the exit code is returned
      by the utility itself, not env.
- 126
- utility was found, but could not be invoked.
- 127
- utility could not be found.
The historic- option has been deprecated but is still
  supported in this implementation.
The env utility conforms to IEEE Std
  1003.2-1992 (“POSIX.2”).
env doesn't handle commands with equal
  (“=”) signs in their names, for obvious reasons.