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@(#)ns.3 6.1 (Berkeley) 04/29/86

C 6 ns_addr, ns_ntoa - Xerox NS(tm) address conversion routines

 "#include <sys/types.h>  "#include <netns/ns.h> 

 "struct ns_addr ns_addr(cp)  "char *cp; 

 "char *ns_ntoa(ns)  "struct ns_addr ns; 

The routine ns_addr() interprets character strings representing XNS addresses, returning binary information suitable for use in system calls. 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 suitable format as input to ns_addr(), above. Any fields lacking super-decimal digits will have a trailing ``H'' appended, so that the number is represented such that applying ns_addr() will return you what you started with.

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 any super-decimal digits present. It is interpreted as octal is there is a leading ``0'' and no super-octal digits. Otherwise, it is converted as a decimal number.

hosts(5), networks(5), None (see BUGS). The string returned by ns_ntoa resides in a static memory area.

ns_addr should diagnose improperly formed input, and there should be an unambiguous way to recognize this.