!force(4)

NAME

!force - Ignore command or macro status

SYNOPSIS

!force [n] command

DESCRIPTION

!force ignores the return status of a command while executing a macro. When MicroEmacs '99 executes a macro, if any command fails, the macro is terminated at that point. If a line is preceded by a !force directive, execution continues whether the command succeeds or not. $status(5) may be used following !force to determine if the command failed or not.

A double !force can be used to catch a user termination (via the abort-command(2) bound to C-g). A macro command aborted by the user will be terminated even with a single !force directive, but not with two. See the example below.

When specifying a numerical argument with a command, it is placed after the !force directive and before the command i.e.

!force 1 forward-char 

EXAMPLE

The following example shows how !force is used in conjunction with $status.

;	Merge the top two windows 

set-window		;remember what window we are at 
1 next-window		;go to the top window 
delete-window		;merge it with the second window 
!force goto-window	;This will continue regardless 
!if $status 
    ml-write "Call PASSED" 
!else 
    ml-write "Call FAILED" 
!endif 

The following example creates an infinite loop that can only be broken out of by a user abort. The calling macro catches this by using a double !force and continues. This concept is used by commands which take a considerable amount of time yet cannot be simply aborted by the user such as the spell-checker's best guess list generator.

define-macro infinite-loop 
    set-variable #l0 1 
    !while 1 
        ml-write &cat "In loop, C-g to exit: " &pinc #l0 1 
    !done 
!emacro 

define-macro catch-abort 
    !force !force infinite-loop 
    ml-write "You will see this" 
!emacro 

SEE ALSO

$status(5).

(c) Copyright JASSPA 1999
Last Modified: 1999/08/24
Generated On: 1999/12/01