VMS Help CC, Run-time functions, strerror  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Maps the error number in error_code to a locale-dependent error
  message string.

  Syntax:

       #include <string.h>

       char *strerror (int error_code);  (ANSI C)

       char *strerror (int error_code [,int vms_error_code]); (Compaq
       C Extension)
       {Relaxed ANSI and VAXC modes only}

 This function uses the error number in error_code to retrieve the
 appropriate locale-dependent error message.  The contents of the
 error message strings are determined by the LC_MESSAGES category of
 the program's current locale.

 For Compaq C (not Compaq C++) in relaxed ANSI mode or VAXC mode,
 strerror has a second argument (vms_error_code), which is used in
 the following way:

       o  If error_code is EVMSERR and there is a second argument,
          then that second argument is used as the VAXC$ERRNO value.

       o  If error_code is EVMSERR and there is no second argument,
          look at VAXC$ERRNO to get the OpenVMS error condition.

 Use of the second argument is not included in the ANSI C definition
 of strerror and is, therefore, not portable.