MPE/iX Intrinsics Reference Manual (32650-90875)

Chapter 5 129
Command Definitions (FCONTROL - FLOCK)
FCONTROL
automatically. For all other types of block mode, disable echo before the
block mode read begins.
Echo should be disabled if a terminal user is entering data that should not
appear on the screen (for example, passwords or lockwords).
Echo should be disabled when connecting some nonsupported devices to an
asynchronous port.
Reset in break mode; not reset after FCLOSE. (Default)
13/U16 Enable echo facility:
Returns a value indicating the previous echo status:
0 Echo ON
1 Echo OFF
When enabled, all characters transmitted to the DTC are echoed onto the
terminal's screen (DTC echo). When the system is initialized, all
characters are echoed except for XON, XOFF, NULL, DEL, and DC2.
During binary reads, all characters are passed as data and echoed. For this
reason, echo should be disabled while in binary mode.
During block mode processing, echo should be disabled and local echo
should be used to cause the terminal to write data back to the screen. If
VPLUS is being used for block mode applications, this is done
automatically. For all other types of block mode, disable echo before the
block mode read begins.
Echo should be disabled if a terminal user is entering data that should not
appear on the screen (for example, passwords or lockwords).
Echo should be disabled when connecting some nonsupported devices to an
asynchronous port.
Reset in break mode; not reset after FCLOSE. (Default)
14/U16 Disable system break function:
Enter a value of 1 to disable the system break function.
System break is enabled by default for any terminal on which a session is
active. If a user presses
BREAK or a process calls the CAUSEBREAK intrinsic,
the system attempts to interrupt the processing and place the terminal at
the command interpreter level. Many system commands and program
commands (that invoke subsystems or run user programs) are breakable.
When the system break is enabled and received, EOR, read timer,
terminal mode, and echo values are saved by the DTS software. This
allows restoration when normal processing is resumed. If a system break
is entered during processing of a character mode read or write, data is lost.
Any read that is interrupted by a break is reissued by the system after a
RESUME command is entered.
Some application programs change the settings of terminals and/or the
characteristics of their device files. In these cases, it may be undesirable to