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Hi,

How do you guys a return a value from assembly code to DOS command prompt?

I know it must terminate by int 21h (4ch) but i needed to return exit status code so that it can be used by the DOS ERRORLEVEL script function.

I tried putting the exit code in AL as like following:

mov ax, 4c00h
int 21h

or

mo ax 4c01h
int 21h

But errorlevel does not seem to be capturing the exit value.
Thanks!

give us more info: how do you run application and how do you check errorlevel. there are situations when errorlevel may be lost, say, if you call command interpereter to run application, you will get success - it means cmd or command.com was executed sucessfully not depending on return of target application.

regards!

hi shoorick
my batch files something looks like below. The script is running from MSDOS real mode and would call test.exe. Test.exe will simply return whatever the parameter on the command line typed on the (2 in this example). Source code is pasted after the batch file content. I thought the script will capture that returned value at errorlevel 2 and goto err2 label. That is my expectation.

I know the errorlevel statements are correct because if I replace test.exe 2 call with choice /c:1234 menu than it correctly captures the keyboard input and goes to the correct label.
Thanks!

===========
batch file content
===========

test.exe 2
if errorlevel 4 goto err4
if errorlevel 3 goto err3
if errorlevel 2 goto err2
if errorlevel 1 goto err1

:err4
:goto end

:err3
:goto end

:err2
:goto end

:err1
:goto end

:end

===========
test.exe source.
===========

ASSUME CS:CODE, DS:DATA, SS:STACK, ES:NOTHING
Main PROC NEAR

; Initialize segment registers.

mov ax, ds
mov es, ax ; (ES) = save PSP in ES.

mov ax, DATA
mov ds, ax
ASSUME DS:DATA

mov ax, STACK
mov ss, ax
ASSUME SS:STACK

; Grab a command line switch from PSP.

mov bp, 82h
mov al, byte ptr es:[bp]
mov ah, 04ch ; (AH) = terminate process fcn code.
int 21h
ret
Main ENDP

ok guys i finally got it working, somehow the return value was being lost for some reason. dO YOU see what the problem in hte above code is? Thanks!