| PATHS(3) | Library Functions Manual | PATHS(3) | 
paths —
default system paths
The <paths.h> header defines
  some default paths used in NetBSD. All defined
  constants are prefixed with _PATH. The constants
  include:
  - The default user search path set by
      login(1) and associated
      utilities such as rshd(8).
      This is defined by _PATH_DEFPATHand includes
      directories such as /usr/bin and
      /usr/local/bin.
- Default paths for some utilities and device nodes. Examples include such
      paths as /dev/null
      (_PATH_DEVNULL), /dev/mem
      (_PATH_MEM), and
      /etc/nologin
      (_PATH_NOLOGIN), among others.
- Paths for some default directories such as /dev
      (_PATH_DEV) and /tmp
      (_PATH_TMP) as well as paths for some
      miscellaneous utilities such as
      csh(1),
      /bin/csh
    (_PATH_CSHELL).
The<paths.h> header is specific
  to NetBSD.