in reply to Are you there Serial?

In a serial protocol the presence of an external device can pe indicated by asserting DSR. FreeBSD, for example, will block on open if DSR is not asserted and clocal is set. Without more infomation ( system, driver, sample code ) it would difficult to provide anything specific to your application.

bitman writes:

"If so, can I get an example?"

Show me yours and I'll show you mine.

s//----->\t/;$~="JAPH";s//\r<$~~/;{s|~$~-|-~$~|||s |-$~~|$~~-|||s,<$~~,<~$~,,s,~$~>,$~~>,, $|=1,select$,,$,,$,,1e-1;print;redo}

In Section Seekers of Perl Wisdom