OpenEuphoria

Re: Standard Input Max Length Limitation

• Posted by Fernando Bauer <fmbauer at hotmail.com> Jun 27, 2007
• 737 views

Matt Lewis wrote:
> 
> Robert Craig wrote:
> > 
> > Pete Lomax wrote:
> > > Matt Lewis wrote:
> > > > Is there a particular reason why you want to run under DOS instead of
> > > > windows?  You can use exwc.exe, which is the console version of the
> > > > interpreter for windows.
> > > I thought about that but a test showed it limited input to 79 characters!
> > 
> > I'm not sure why that is, but there's no magic number built into
> > Euphoria itself that limits gets(0). It will happily malloc
> > space for millions of characters.
> 
> Yep, and it works as expected if you pipe stdio instead of typing it.
>  
> > If I open a command-prompt window with XP,
> > and hold down the 'x' key, it complains that
> > "'xxxxxxxxxxxxxxxxxxxxxxxxxxxxx' is not recognized as an internal 
> > or external command, operable program or batch file"
> > 
> > But when I reach 259 x-characters it changes the complaint to:
> > "The input line is too long."
> > 
> > Note, I'm not running a Euphoria program at all,
> > just entering a command at the prompt.
> 
> Yeah, I'm that's a limitation of cmd.exe, but I was surprised to find that 
> I could only get 79 characters typed into the console when I run this code:
> }}}
<eucode>
> ? length( gets(0) & 0 ) - 1
> </eucode>
{{{

> I suspect that it's something to do with the console buffer not wanting to 
> do a line wrap, but I haven't dug deep enough to figure out if that's true.
> 
> I haven't tried at all with linux.
> 
> Matt


Hi,

If you run for DOS (ex.exe) it results 128 in my system (WinXP).
If I am right, the result obtained (79) in case of Windows is related to the
position, not to the quantity of characters.
Try this:
position(1,70)
? length( gets(0) & 0 ) - 1

In file be_runtime.c we can read in the function key_gets() (from line 4529 of
version 3.0.2):
	    if (column < 79) {
		len = strlen(input_string);
		one_char[0] = c;
		...
This function is called by wingetch() which is called by EGets().
If the exw.exe is compiled with BORLAND or LCC, probably the result will be
different, because key_gets() isn't called.
Maybe Rob could better explain that limit for Windows?

Regards,
Fernando
Porto Alegre/RS
Brazil