KAddressBook Dialer

[Roby <ElectricalSciences@Adelphia.net>]

I'm trying to build this missing piece: something to cause my modem to dial
a telephone number input as a command parameter from KAddressBook.

dial 5551212

I tried echo ATDT5551212 > /dev/ttyS0

Result: modem lights flash briefly, short burst of dialtone from speaker, no
dialing.

Booted DOS and found that echo ATDT5551212 > COM1: dials just fine.

Back to linux, wrote a little c program:

#include <stdio.h>

#ifdef __linux__
    #define COMPORT  "/dev/ttyS0"
#else
    #define COMPORT  "COM1:"
    #endif

int main( void )
{
FILE *Port;

if( ( Port =fopen( COMPORT, "a+t" ) ) == NULL )
        {
        printf( "Can't open %s for writing.\n", COMPORT );
        return( 1 );
        }

fprintf( Port, "ATZ\nATDT5551212\n" );
fclose( Port );
return( 0 );
}

and tried it.  Under linux, all that happens is der blinkenlites but no
dialtone, no dialing.  Same source compiled and run under DOS fails at
fopen().

I can send ATDT5551212 from minicom and linux dials as desired, but I need a
little program that accepts the number as an input param.

What magic is missing here?

Thanks!
Roby