number-of-socket-descriptors

Specifies the name of a field containing the highest socket descriptor specified in any of the lists + 1. Only socket descriptors whose value is less than number-of-socket-descriptors are considered in servicing the request.

read-list

Specifies the name of an area containing a bit list identifying the socket descriptors to be examined for a "ready to read" condition. Only socket descriptors whose corresponding bit in the bit list is on are considered. On return, the bits that are set indicate the descriptors that are ready to read. Specify NULL if the read-list is to be ignored.

read-list-length

Specifies the name of a fullword field containing the length in bytes of read-list.

read-list-length can be specified as an absolute expression. read-list-length must be a multiple of 4; specify 0 if the read-list is to be ignored.

write-list

Specifies the name of an area containing a bit list identifying the socket descriptors to be examined for a "ready to write" condition. Only socket descriptors whose corresponding bit in the bit list is on are considered. On return, the bits that are set indicate the descriptors that are ready to write. Specify NULL if the write-list is to be ignored.

write-list-length

Specifies the name of a fullword field containing the length in bytes of write-list.

write-list-length can be specified as an absolute expression. write-list-length must be a multiple of 4; specify 0 if the write-list is to be ignored.

exception-list

Specifies the name of an area containing a bit list identifying the socket descriptors to be examined for an exception condition. Only socket descriptors whose corresponding bit in the bit list is on are considered. On return, the bits that are set indicate the descriptors that have had exceptions. Specify NULL if the exception-list is to be ignored.

exception-list-length

Specifies the name of a fullword field containing the length in bytes of exception-list.

exception-list-length can be specified as an absolute expression. exception-list-length must be a multiple of 4; specify 0 if the exception-list is to be ignored.

option

Specifies the name of a fullword field containing the way the different bits are interpreted in the different bit-lists. option can be specified as an absolute expression. For a list of options that can be specified, see Notes.

timeval-structure

Specifies the name of the area containing the TIMEVAL structure. If the parameter is assigned to NULL, SELECT waits until at least one of the descriptors is ready. If the time-out value (number of seconds + number of microseconds) is 0, SELECT checks the descriptors and returns immediately without waiting. The TIMEVAL structure is generated by the #SOCKET TCPIPDEF macro call and described in the SOCKET-TIMEVAL record.

returned-number-of-descriptors

Specifies the name of a fullword field in which the total number of ready descriptors is returned.

ecb

Specifies the name of an area containing a CA IDMS ECB.

ecb-list

Specifies the name of an area containing a CA IDMS ECB list. Each entry in the ECB list is represented by two fullwords:

• The first fullword is a pointer to the ECB.
• The second fullword is zero, except for the last entry in the list. In this case the high-order bit is turned ON to identify the end of the ECB list.