[BUG] GPC - a char killer?_(re)

Fri, 11 Apr 1997 17:33:07 +0200 (MET DST)

According to Sven Engelhardt:

The compiled program "eats up" the first char if standard input
is not a terminal.  This is because when `Input' is `reset' at
startup, the first char is read in to `Input's file buffer
variable.  If you would `read' the char rather than `getchar'ring
it, you would get it.

To work around, use the `eoln' function to check whether a char
has been read in like this:

> program test1(input,output);
> 
> function getchar:integer; C;
> 
> var k:integer;
> 
> begin
    if not eoln ( Input ) then
      k:= ord ( Input^ )
    else
>     k:=getchar;
>   while (k<>-1) do 
>   begin
>     writeln(k);
>     k:=getchar;
>   end;
> end.

To fix this bug (?) it would be necessary to rewrite parts of the RTS,
but I am not sure whether we should do that because I can imagine that
GPC's behaviour is as the ISO Standard requires.  (But I am not in the
position to judge that. ;-)

Hope this helps,

    Peter

  Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer
peter.gerwinski@uni-essen.de - http://home.pages.de/~peter.gerwinski/ [970201]
 maintainer GNU Pascal [970401] - http://home.pages.de/~gnu-pascal/ [970125]

Peter Gerwinski (peter@agnes.dida.physik.uni-essen.de)