bonak%cs.uiowa.edu@RELAY.CS.NET (08/30/87)
Thanks to all the people who helped me with my query
regarding how to specify a path in the function fopen.
Nobody responded to the second question so I'll try again:
Does anybody know a way of getting MS-DOS to use the return
value of an exit(value) that comes from a C program
termination? I.e. I'd like to know (at a DOS level) whether
a program terminated with exit(0) or exit(1).
esmail
p.s.: I am using Turbo C and DOS 3.1toma@killer.UUCP (Tom Armistead) (08/31/87)
In article <9061@brl-adm.ARPA>, bonak%cs.uiowa.edu@RELAY.CS.NET (Esmail Bonakdarian) writes: > > Does anybody know a way of getting MS-DOS to use the return > value of an exit(value) that comes from a C program > termination? I.e. I'd like to know (at a DOS level) whether > a program terminated with exit(0) or exit(1). You have something in dos called errorlevel that will give you the value you exit()ed with. This could be used in a batch file like this... . REM RUN MAIN PROGRAM . MAINPGM . IF ERRORLEVEL 0 GOTO GOOD . IF ERRORLEVEL 1 GOTO BAD . IF ERRORLEVEL 2 GOTO HAWAII . :GOOD . ECHO WE GOT A GOOD RETURN . GOTO END . :BAD . ECHO WE GOT A BAD RETURN . GOTO END . :HAWAII . ECHO WE ARE GOING TO HAWII . :END . EXIT the number following 'ERRORLEVEL' will be the number you exited with. Hope this will help... toma UUCP: ihnp4\ \killer!toma infoswx!convex!dj3b1/ Tom Armistead -- UUCP: ihnp4\ \killer!toma infoswx!convex!dj3b1/ Tom Armistead
PEPRBV%CFAAMP.BITNET@wiscvm.wisc.EDU (Bob Babcock) (08/31/87)
>> Does anybody know a way of getting MS-DOS to use the return >> value of an exit(value) that comes from a C program >> termination? I.e. I'd like to know (at a DOS level) whether >> a program terminated with exit(0) or exit(1). If you are running the program in question from another program, you can get the return code with INT 21h, function 4dh. If you are running the program from the DOS prompt, I think the error code is lost by the time you get back to the prompt. The solution is to run the program from a batch file and use an IF ERRORLEVEL test. You could have a BAT file called RUN which looked something like this: ECHO OFF %1 IF ERRORLEVEL 1 ECHO %1 RETURN CODE WAS NOT ZERO Then say RUN program_name instead of program_name. It would be nice if DOS told you the return code, but I guess the philosophy is that the program should give a useful error message, and the only use for the return code is controlling the flow of a batch file or letting the invoking program know (since it doesn't see screen messages).
jvc@mirror.UUCP (09/01/87)
/* Written 7:35 pm Aug 30, 1987 by toma@killer.UUCP in comp.lang.c */ >You have something in dos called errorlevel that will give you the value >you exit()ed with. This could be used in a batch file like this... > >. REM RUN MAIN PROGRAM >. MAINPGM >. IF ERRORLEVEL 0 GOTO GOOD >. IF ERRORLEVEL 1 GOTO BAD >. IF ERRORLEVEL 2 GOTO HAWAII >. :GOOD >. ECHO WE GOT A GOOD RETURN >. GOTO END >. :BAD >. ECHO WE GOT A BAD RETURN >. GOTO END >. :HAWAII >. ECHO WE ARE GOING TO HAWII >. :END >. EXIT > >the number following 'ERRORLEVEL' will be the number you exited with. He's got the right idea but it won't work as coded. Refer to page 7-34 of DOS 3.2 Reference, paragraph 2 (approx.): "ERRORLEVEL number is true if the previous program had an exit code of number or higher. The number is specified as a decimal value." In order for the above code segment to work you must reverse the order of the IF statements. It would also be wise to cover the case in which the program might return a 3 or greater since in this example you only want to GOTO HAWAII if you get a return of 2. Also note that EXIT won't terminate a batch file and therefore should not be in this code segment. (DOS 3.1, 3.2) Corrected code segment: REM RUN MAIN PROGRAM MAINPGM REM Look at return codes REM A return of 3 or greater is unexpected IF ERRORLEVEL 3 GOTO UNEXPECTED REM Now we can test for 2 (or greater but we've already REM handled values greater than 2) IF ERRORLEVEL 2 GOTO HAWAII REM Test for return of 1 IF ERRORLEVEL 1 GOTO BAD REM Test for return of 0 IF ERRORLEVEL 0 GOTO GOOD :GOOD ECHO WE GOT A GOOD RETURN GOTO END :BAD ECHO WE GOT A BAD RETURN GOTO END :HAWAII ECHO WE ARE GOING TO HAWII GOTO END :UNEXPECTED ECHO Unexpected return value ( >=3 ) :END REM No more commands after this so execution terminates ------------------------------------------------------------------------- Jim Champeaux jvc@mirror.TMC.COM {mit-eddie, ihnp4, wjh12, cca, cbosgd, seismo}!mirror!jvc Mirror Systems, 2067 Massachusetts Avenue, Cambridge, MA 02140 Telephone: (617) 661-0777
V4007%TEMPLEVM.BITNET@wiscvm.wisc.EDU (Mike Brower) (09/01/87)
Dear Bob
Account V4007 of TempleVm is no longer Mike Brower's account. The
new user is a consultant named Franky Choi.marc@mfbbs.UUCP (09/12/87)
Followup-To: In article <1445@killer.UUCP> toma@killer.UUCP (Tom Armistead) writes: >In article <9061@brl-adm.ARPA>, bonak%cs.uiowa.edu@RELAY.CS.NET writes: >> value of an exit(value) that comes from a C program >> termination? > >. MAINPGM >. IF ERRORLEVEL 0 GOTO GOOD >. IF ERRORLEVEL 1 GOTO BAD >. IF ERRORLEVEL 2 GOTO HAWAII > [correct stuff deleted] >--- >UUCP: killer!toma >Tom Armistead That batch file won't work (don't worry, I consider it Microsofts fault!). DOS tests errorlevels by equal to or greater than the number you are testing against. This means in your batch file, EVERY errorlevel above and equal to 0 would 'GOTO GOOD'. So, the correct batch file would be: IF ERRORLEVEL 2 GOTO HAWAII IF ERRORLEVEL 1 GOTO BAD IF ERRORLEVEL 0 GOTO GOOD [etc] -- Marc Randolph UUCP: ...!rutgers!pbox!svo!mfbbs!marc FidoNet: 170/329 or 170/220