OpenEuphoria

Re: Stumped by open("PRN","w")

• Posted by cEnsE <cense at MAIL.RU> Jan 21, 2001
• 633 views

On Sun, 21 Jan 2001, Jim wrote:
>> The following code snippet is from a Windows program using Win32Lib.ew. If I
>> run it with exw.exe, on a machine with no
>> printer (or anything else) attached to the parallel port, it executes the
>> open("PRN","w") statement and assigns a valid
>> file handle (4), where  I would have expected a -1.  It also continues to the
>> puts(ThePrinter,line) and executes that.
>> In fact, under exw, the program runs to normal completion, when I would have
>> expected an abnormal termination.
>>
>> The very same code, copied to an .ex file, and run under ex.exe executes in
>> the same way, but then crashes with a DOS
>> Critical Error when it hits the puts(ThePrinter,line) statement. In both
>> versions, I would have expected a -1 on the
>> open for the non-existent printer.
>>
>> Can someone help me understand what I'm doing wrong here?
>>
>> Thanks.
>>
>> Totally perplexed.
>>
>> Jim
>>
>> ------------------- <begin code >
>> object  line
>> integer Patterns,ThePrinter,result
>>
>>           Patterns=open( "PATTERNS.TXT","rb" )        -- any text file of 80
>>           or more char.
>>           if Patterns = -1  then
>>              result = message_box( "Open Patterns.txt FAILED in
>>              OnClick_ButtonPrint. Aborting. ","ERROR!", {} ) abort(1)
>>
>>           end if
>>
>>           ThePrinter = open("PRN","w")

What exactly is this "PRN" ? the way you have it coded, if im not mistaken,
the open call will open a file in the current directory called PRN. I may
very well be mistaked but from a quick look over this "PRN" stands out as a
possible  source of your problem.


>>           if ThePrinter = -1  then
>>              result = message_box( "Unable to find a printer; skipping.",
>>              "ERROR!", {} )   -- never executed, although
>> no printer
>>           else
>>              while 1 do
>>                    line=gets(Patterns)
>>                    if atom(line) then
>>                       close(Patterns)
>>                       close(ThePrinter)
>>                       exit
>>                    end if
>>                    line=line[1..80]&"\n"
>>                    puts(ThePrinter,line)    --   processed OK under exw.exw ;
>>                    crashes to DOS under ex.exe
>>              end while
>>           end if
>> ---------< end code >

I hope that helps, but if not, i tried.

--
evil, corruption and bad taste
^[cense]