[racket] A strange DrRacket interaction

text:ports (in the framework) is where the implementation of DrRacket's
port is if that helps.

Robby


On Fri, Feb 8, 2013 at 9:08 AM, Jens Axel Søgaard <jensaxel at soegaard.net>wrote:

> 2013/2/7 Jens Axel Søgaard <jensaxel at soegaard.net>:
>
> This is an update:
>
>   1. Danny confirms that the bug is repeatable on his machine.
>
>   2. Weirdness on first character of the input reminded him
>       on this bug:
>           http://comments.gmane.org/gmane.comp.lang.racket.user/1759
>
>  3. Wrapping the call to system* with
>      (parameterize ([current-input-port (open-input-bytes #"abcde\n") …)
>      make the program works expected.
>
> The last point imply that the behaviour has something to do with the
> "buffer ports" that DrRackets sets up to convert from ports used
> in DrRacket to the file-stream-port need by system*.
>
> 4.  The equivalent C program (see below) does not trigger the error.
>
> #include <stdio.h>
> int main(int argc, char **argv) {
>    char str[200];
>    printf("Enter string:\n");
>    fgets(str, 200, stdin);
>    printf("%s\n",str);
>    return 0;
> }
>
> /Jens Axel
>
>
>
> > I am basically calling (system* "fpctest") where
> > fpctest is the result of compiling this program with fpc:
> >
> > program fpctest;
> > var s:string;
> > begin
> >   writeln('Enter string:');
> >   readln(s);
> >   writeln(s);
> >   writeln('hello');
> > end.
> >
> > The interaction in DrRacket is:
> >
> > 1. Input box appears
> > 2. I enter   abcdef
> > 3. abcdef appears where the input box was displayed.
> > 4. This error messages is displayed:
> >         .../Racket v5.3.2/collects/racket/private/port.rkt:128:15:
> >          write-bytes-avail: output port is closed
> > 5. The following is displayed:
> >     Enter string:
> >     bcdef
> >     hello
> >
> > There are three things of interest:
> >   1. The input box appears before "Enter string" is
> >        written to the screen.
> >      (Is this the Pascal program misbehaving?)
> > 2. The error that points to a private file, which
> >     seems odd.
> > 3. The a is missing from the output of the
> >      Pascal program.
> >
> > Running the program from command line racket
> > seems to work every time.
> >
> > Once in while (say 1 out of 10 times) it works in DrRacket too.
> >
> > Any ideas what can explain what I see?
> >
> > Images: http://imgur.com/wSE6De5
> >               http://imgur.com/hdYJcKx
>
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>
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