NS(3)

NAME
ns_addr, ns_ntoa - Xerox NS(tm) address conversion routines

LIBRARY
libc

SYNOPSIS
#include <sys/types.h>
#include <netns/ns.h>
struct ns_addr
ns_addr(char *cp);
char *
ns_ntoa(struct ns_addr ns);

DESCRIPTION
The routine ns_addr() interprets character strings representing XNS addresses, returning binary information suitable for use in system calls. The routine ns_ntoa() takes XNS addresses and returns ASCII strings representing the address in a notation in common use in the Xerox Development Environment:

<network number>.<host number>.<port number>

Trailing zero fields are suppressed, and each number is printed in hexadecimal, in a format suitable for input to ns_addr(). Any fields lacking super-decimal digits will have a trailing ‘H’ appended.

Unfortunately, no universal standard exists for representing XNS addresses. An effort has been made to insure that ns_addr() be compatible with most formats in common use. It will first separate an address into 1 to 3 fields using a single delimiter chosen from period ‘’., colon ‘’: or pound-sign ‘#’. Each field is then examined for byte separators (colon or period). If there are byte separators, each subfield separated is taken to be a small hexadecimal number, and the entirety is taken as a network-byte-ordered quantity to be zero extended in the high-network-order bytes. Next, the field is inspected for hyphens, in which case the field is assumed to be a number in decimal notation with hyphens separating the millenia. Next, the field is assumed to be a number: It is interpreted as hexadecimal if there is a leading ‘0x’ (as in C), a trailing ‘H’ (as in Mesa), or there are any super-decimal digits present. It is interpreted as octal is there is a leading ‘0’ and there are no super-octal digits. Otherwise, it is converted as a decimal number.

RETURN VALUES
None. (See BUGS.)

SEE ALSO
hosts(5), networks(5)

HISTORY
The ns_addr() and ns_toa() functions appeared in 4.3BSD.

BUGS
The string returned by ns_ntoa() resides in a static memory area. The function ns_addr() should diagnose improperly formed input, and there should be an unambiguous way to recognize this.