Standard Library function that allows PV-WAVE to be called by external routines written in C.

None.

result—The number of parameters returned to UNIX_LISTEN.

Procedure—A string that is set by the client and retrieved by UNIX_LISTEN. Its intended use is to control program flow within the server (PV‑WAVE).

Program—An integer used as an identifier for the external routines. If an external routine (or client) calls call_wave, UNIX_LISTEN checks if the value of Program matches the value of the program parameter in call_wave sent by the client. The client’s program identifier is set by the program parameter in the call_wave function call.

User—String set by client and retrieved by UNIX_LISTEN. It’s intended use is for controlling access to the server, as an authentication mechanism.

UNIX_LISTEN waits until an external routine calls call_wave, and then returns the number of parameters passed to UNIX_LISTEN.

Parameters are passed into PV‑WAVE through the common block UT_COMMON. A maximum of thirty parameters can be passed.

UT_COMMON is included in the server routine with the command @UT_COMMON. The first of the thirty available parameters is ut_param0, the second is ut_paraml, and the thirtieth parameter is ut_param29.

As well as being returned by UNIX_LISTEN, the number of parameters is also contained in the variable ut_num_params in the common block.

CALL_UNIX, LINKNLOAD, SPAWN (UNIX), UNIX_REPLY

For more information, see the PV‑WAVE Application Developer’s Guide.