Topic summary
Coreutils
Extracted from the Wikipedia article GNU Core Utilities.
The GNU Core Utilities or Coreutils is a collection of GNUsoftware that implements many standard, Unix-based shellcommands. The utilities generally provide POSIX compliant interface when the POSIXLY_CORRECT environment variable is set, but otherwise offers a superset to the standard interface. For example, the utilities support long options and options after parameters. This environment variable enables a different functionality in BSD.