Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!munnari.oz.au!bruce!dbrmelb!davidp
From: davidp@dbrmelb.dbrhi.oz (David Paterson)
Newsgroups: comp.lang.fortran
Subject: Bug cured by debugging output.
Message-ID: <711@dbrmelb.dbrhi.oz>
Date: 10 Jan 90 03:29:45 GMT
Organization: CSIRO, Div. Building Constr. and Eng'ing, Melb., Australia
Lines: 27



I've been programming in Fortran 77 for ten years now and have seen
all sorts of things but this is one of the strangest.

The program below works perfectly when run with:
Microsoft FORTRAN77 V3.31 August 1985           and
Microsoft (R) 8086 Object Linker Version 3.04.


      CHARACTER*80 LINE
      DATA XLO,XHI,YLO,YHI/0.,10.,0.,10./
 49   WRITE(*,50) XLO,XHI,YLO,YHI
 50   FORMAT(' Type XLO,XHI,YLO,YHI <',3(G9.3,','),G9.3,'>: ')
      READ(*,'(A80)') LINE
      WRITE(*,*) 
      READ(LINE,*,END=49,ERR=49) XLO,XHI,YLO,YHI
      STOP
      END

However, if the line 'WRITE(*,*)' is removed then the program
fails miserably (endless loop). Why?

-------------------------------------------------------------------
David Paterson
CSIRO Division of Building, Construction and Engineering
Highett, Victoria, AUSTRALIA