Format

                                          .-,--TCP----------.   
>>-SOCKET--(--"GETSERVBYPORT"--,--portid--+-----------------+--->
                                          '-,--protocolname-'   

>--)-----------------------------------------------------------><

Parameters

portid

The port number of the service

protocolname

The name of a network protocol, for example, TCP or UDP. By default, the protocolname parameter is set to TCP.

Returned value

This command returns a string that contains the return code, service name, the port number that the service is using, and the network protocol, for example, 0 FTP 21 TCP. The return code can be 0 or the REXX API error number. The return code 0 indicates that the requested socket command was completed successfully.

See Socket call error return codes for additional information about the numeric error codes that are returned by this command.

LE C/C++ equivalent

struct servent *getservbyport(int port, char *proto);

Code example

/* REXX EZARXR18 */
/*
 * This sample demonstrates the use of the GETSERVBYPORT
 * socket command.
 */
if perror(socket("INITIALIZE","MYSET01"),"INITIALIZE") = 0,
   then do
   src = socket("GETSERVBYPORT","21");
   Say "Port 21 is using service "SUBWORD(src,2);
end;
src = perror(socket("TERMINATE","MYSET01"),"TERMINATE");
exit 0;

/* This routine returns -1 if the first word if arg 1 is not zero */
perror: if word(arg(1),1) = 0 then return 0; else
    Say arg(2) "Error : "arg(1);
    return -1;