The chat program will terminate with the following completion
codes.
0 The normal termination of the program. This indicates that
the script was executed without error to the normal
conclusion.
1 One or more of the parameters are invalid or an expect
string was too large for the internal buffers. This
indicates that the program as not properly executed.
2 An error occurred during the execution of the program.
This may be due to a read or write operation failing for
some reason or chat receiving a signal such as SIGINT.
3 A timeout event occurred when there was an expect string
without having a "-subsend" string. This may mean that you
did not program the script correctly for the condition or
that some unexpected event has occurred and the expected
string could not be found.
4 The first string marked as an ABORT condition occurred.
5 The second string marked as an ABORT condition occurred.
6 The third string marked as an ABORT condition occurred.
7 The fourth string marked as an ABORT condition occurred.
... The other termination codes are also strings marked as an
ABORT condition.
Using the termination code, it is possible to determine which
event terminated the script. It is possible to decide if the
string "BUSY" was received from the modem as opposed to "NO DIAL
TONE". While the first event may be retried, the second will
probably have little chance of succeeding during a retry.
