NLSREQUEST(3NSL) Networking Services Library Functions NLSREQUEST(3NSL)

nlsrequest - format and send listener service request message

#include <listen.h>
int nlsrequest(int fildes, char *service_code);
extern int _nlslogt_errno;
extern char *_nlsrmsg;

Given a virtual circuit to a listener process (fildes) and a service code of a server process, nlsrequest() formats and sends a service request message to the remote listener process requesting that it start the given service. nlsrequest() waits for the remote listener process to return a service request response message, which is made available to the caller in the static, null-terminated data buffer pointed to by _nlsrmsg. The service request response message includes a success or failure code and a text message. The entire message is printable.

The success or failure code is the integer return code from nlsrequest(). Zero indicates success, other negative values indicate nlsrequest() failures as follows:


Error encountered by nlsrequest(), see t_errno.

Positive values are error return codes from the listener process. Mnemonics for these codes are defined in <listen.h>.


Request message not interpretable.


Request service code unknown.


Service code known, but currently disabled.

If non-null, _nlsrmsg contains a pointer to a static, null-terminated character buffer containing the service request response message. Note that both _nlsrmsg and the data buffer are overwritten by each call to nlsrequest().

If _nlslog is non-zero, nlsrequest() prints error messages on stderr. Initially, _nlslog is zero.

shared object

See attributes(7) for descriptions of the following attributes:

MT-Level Unsafe

t_error(3NSL), t_rcv(3NSL), t_snd(3NSL), attributes(7), nlsadmin(8)

nlsrequest() cannot always be certain that the remote server process has been successfully started. In this case, nlsrequest() returns with no indication of an error and the caller will receive notification of a disconnect event by way of a T_LOOK error before or during the first t_snd() or t_rcv() call.

These interfaces are unsafe in multithreaded applications. Unsafe interfaces should be called only from the main thread.

November 14, 2002 OmniOS