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European MS-DOS 4.0 - SET SIGNAL HANDLER

AH = 8Ch
AL = signal number (see #01793)
BL = action (see #01794)
DS:DX -> signal handler (see #01795)

Return:
CF clear if successful
AL = previous action
ES:BX -> previous signal handler
CF set on error
AX = error code (01h,invalid SigNumber or Action)
(see #01680 at AH=59h/BX=0000h)

Desc: Set the routine which will be invoked on a number of exceptional conditions

Note: All signals will be sent to the most recently installed handler

See Also: AH=8Dh

(Table 01793)
Values for European MS-DOS 4.0 signal number:
01h    SIGINTR         Control-C or user defined interrupt key
08h    SIGTERM         program termination
09h    SIGPIPE         broken pipe
0Dh    SIGUSER1        reserved for user definition
0Eh    SIGUSER2        reserved for user definition


(Table 01794)
Values for signal action:
00h    SIG_DFL         terminate process on receipt
01h    SIG_IGN         ignore signal
02h    SIG_GET         signal is accepted
03h    SIG_ERR         sender gets error
04h    SIG_ACK         acknowledge received signal and clear it, but don't
change current setting


(Table 01795)
Values signal handler is called with:.
AL = signal number (see #01793).
AH = signal argument

Return:
RETF, CF set: terminate process.
RETF, CF clear, ZF set:
Abort any interrupted system call with an error.
RETF, CF clear, ZF clear:
Restart any interrupted system call.
IRET:
Restart any interrupted system call

Note: The signal handler may also perform a nonlocal GOTO by resetting the stack pointer and jumping; before doing so, it should dismiss the signal by calling this function with BL=04h

Category: DOS Kernel - Int 21h - E

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