IPX/SPX Programming Manual

Library Routines

HP NonStop IPX/SPX Programming Manual—528022-001

5-6

Procedure Prototypes

Each socket function described in this manual is available to be “sourced” into TAL

programs. Either the entire set of prototypes or individual functions may be sourced.

Because TAL procedures cannot be type cast for returning pointers, those procedures

that actually do return pointers are typed as INT(32). It is the programmer’s

responsibility to redefine the returned INT(32) as a pointer to the appropriate

structure. It may be helpful for the TAL programmer to think of these pointers to

structures as pointers to arrays.

For NonStop IPX/SPX, if you wish to mix TAL code and C code to reference the socket

interface, a problem arises. As TAL interfaces only with uppercase external names, all

the socket procedure names are changed to uppercase. This is contrary to how C

modules normally reference the same entry points. To maneuver around this problem,

an “include file” named PROCRDEF is supplied with the socket library which transforms

all socket procedure names in a C module to uppercase.

Implications of the C Socket Library

TAL programs bound with the socket library differ significantly from applications written

completely in C. TAL programs miss the normal C run-time library and the normal

startup logic. The full C run-time library is replaced by a subset of minimal functions

that are used by the socket library. This means that a programmer who wishes to

combine C and TAL procedures to implement an application is bound by this same

minimal C run-time library functionality.

The TAL version of the socket library is based on the C large-memory model, so all

pointers must be 4-byte pointers.

The pTAL version of the socket library is based on the C wide-data model, so all

pointers must be 4-byte pointers.

The function provided include:

•

Very minimal STDIO functionality:

fopen

fgets

fclose

•

‘str...’ functionality

•

‘mem...’ functionality

•

sprintf, but not fprintf or printf

•

All functions implemented as macros

•

errno global variable

Routines available to access ‘errno’ and ‘h_errno’ variables: