Parameter values set by the application

SOC-FUNCTION

A 16-byte character field containing SELECT. The field is left-aligned and padded on the right with blanks.

MAXSOC

A fullword binary field that specifies the largest socket descriptor value that is being checked. The SELECT call tests only bits that are in the range 0 through the MAXSOC value minus 1. For example, if you set the MAXSOC value to 50, the range is 0 – 49.

TIMEOUT

If TIMEOUT is a positive value, it specifies the maximum interval to wait for the selection to complete. If TIMEOUT-SECONDS is a negative value, the SELECT call blocks until a socket becomes ready. To poll the sockets and return immediately, specify the TIMEOUT value to be 0.

TIMEOUT is specified in the two-word TIMEOUT as follows:

TIMEOUT-SECONDS, word one of the TIMEOUT field, is the seconds component of the timeout value.
TIMEOUT-MICROSEC, word two of the TIMEOUT field, is the microseconds component of the timeout value (0—999999).

For example, if you want SELECT to time out after 3.5 seconds, set TIMEOUT-SECONDS to 3 and TIMEOUT-MICROSEC to 500000.

RSNDMSK

A bit string sent to request read event status.

For each socket to be checked for pending read events, the corresponding bit in the string should be set to 1.
For sockets to be ignored, the value of the corresponding bit should be set to 0.

If this parameter is set to all zeros, the SELECT will not check for read events.

WSNDMSK

A bit string sent to request write event status.

For each socket to be checked for pending write events, the corresponding bit in the string should be set to 1.
For sockets to be ignored, the value of the corresponding bit should be set to 0.

If this parameter is set to all zeros, the SELECT will not check for write events.

ESNDMSK

A bit string sent to request exception event status.

For each socket to be checked for pending exception events, the corresponding bit in the string should be set to 1.
For each socket to be ignored, the corresponding bit should be set to 0.

If this parameter is set to all zeros, the SELECT will not check for exception events.