TCP/IP API Support › Socket Call Interface for COBOL › Notes

Notes

• If an optional parameter is not specified in the parameter list, it should be replaced by a parameter that depends on the COBOL compiler:
  • For COBOL for z/OS, specify reserved keyword OMITTED.
  • For ANSI COBOL85, specify BY VALUE dummy-variable; dummy-variable should be set to 0.
• The following pre-defined records are provided during installation to assist in writing socket applications:
  • SOCKET-CALL-INTERFACE—Describes the socket functions, return codes, and errno values used to issue all socket requests.
  • SOCKET-MISC-DEFINITIONS—Describes options and flags specific to individual functions.
  • SOCKET-MISC-DEFINITIONS-2—Describes the flags specific to the IOCTL function.
  • SOCKET-SOCKADDR-IN, SOCKET-SOCKADDR-IN6, SOCKET-HOSTENT, SOCKET-SERVENT, SOCKET-TIMEVAL, and SOCKET-ADDRINFO—Describe structures that may be useful for certain socket applications.
• The SOCKET-CALL-INTERFACE record contains fields that can be used for the socket call common parameters:
  • function
  • return-code
  • errno
  • reason-code

  Each supported function is represented by a field, whose value is the function number. The following example illustrates how to issue a READ socket request using the fields within the SOCKET-CALL-INTERFACE record:

  CALL 'IDMSOCKI' USING SOCKET-FUNCTION-READ,
                      SOCKET-RETCD,
                      SOCKET-ERRNO,
                      SOCKET-RESNCD,
                      . . .
  

  Note: The SOCKET-CALL-INT record is identical to theSOCKET-CALL-INTERFACE record except that functions values are defined as condition names instead of fields. Unless storage is critical, the SOCKET-CALL-INTERFACE record should be used.

• The program associated with a server task (a task started by a generic listener) must specify the information in the following sections:
  • In the LINKAGE SECTION:

                   01  SOCKET-PARMS        PIC X(80).
                   01  SOCKET-DESCRIPTOR   PIC S9(8) COMP.
                   01  SOCKET-RESUME-COUNT PIC S9(8) COMP.
    
    

  • In the PROCEDURE DIVISION:

                   PROCEDURE DIVISION USING
                             SOCKET-PARMS,
                             SOCKET-DESCRIPTOR,
                             SOCKET-RESUME-COUNT.