Better use the call RfcOpenEx.
The following function opens an RFC connection. All parameters are passed as single fields:
RFC_HANDLE SAP_API RfcOpenExt(char* destination,
RFC_MODE mode,
char* hostname,
int
sysnr,
char* gateway_host,
char* gateway_service,
char* client,
char* user,
char* password,
char* language,
int
trace);
RFC opens the connection using the given options, and returns a handle for the connection established.
The input parameters to this function carry the same information as that sent to RfcOpen, but not packed in structures. Instead, individual fields are sent. At any given time, some of these fields are empty, depending on the value of mode:
· RFC_MODE_R3ONLY
The fields hostname, sysnr, gateway_host, and gateway_service have valid information in them.
· RFC_MODE_CPIC
Only the fields gateway_host, and gateway_service have valid information in them.
This function is defined in SAPRFC.H.
· Returns a handle to the RFC connection (RFC_HANDLE) or
· Returns RFC_HANDLE_NULL
· destination
name of destination
· mode
connection mode (RFC_MODE)
· hostname
hostname of target system
· sysnr
system number (0-99)
· gateway_host
gateway hostname or NULL
· gateway_service
gateway service or NULL
· client
signon data: client
· user
signon data: user
· password
signon data: password
· language
signon data: language
· trace
If the field trace contains a non-zero value, the outgoing and incoming RFC data are written to a trace file dev_rfc in the current directory. A trace file is also written on the target system. On SAP systems, you can view this file using the utility program RSRFCTRC.
See also RfcOpen, RfcOpenExtV3 and RFC_OPTIONS for further description of these fields. In general, the input parameters allow the system to avoid accessing the sideinfo table. If you send the relevant parameters as null fields (hostname for SAP system, the gateway fields for R/2), the sideinfo table will be accessed to get the needed information.
If you call RfcOpenExt with an invalid password, the function does not immediately fail. However, the subsequent call to RfcCallExt (or RfcCallReceiveExt) will fail.