Path: utzoo!attcan!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.unix.questions
Subject: Re: Question on printf()
Message-ID: <1990Jun15.120003.25175@virtech.uucp>
Date: 15 Jun 90 12:00:03 GMT
References: <24674.266e3b81@kuhub.cc.ukans.edu> <1990Jun8.030206.4532@virtech.uucp> <1990Jun15.042610.18292@dasys1.uucp>
Reply-To: cpcahil@virtech.UUCP (Conor P. Cahill)
Organization: Virtual Technologies Inc., Sterling VA
Lines: 25

In article <1990Jun15.042610.18292@dasys1.uucp> jpr@dasys1.UUCP (Jean-Pierre Radley) writes:
>In article <1990Jun8.030206.4532@virtech.uucp> cpcahil@virtech.UUCP (Conor P. Cahill) writes:
>> [as one of the ways to geta printf() call to show up right away]
>
>>3. add a setbuf(stdout,(char *) 0) at the begining of your program.  This 
>>turns off all output buffering and can have a detrimental effect on the
>>overall performance of your software.  
>
>Why is that?

Because it causes all output be be written immediatly.  If you are using
something like curses for a full screen program it noticably slows down 
the screen drawing. (Enough that an end-user will notice and complain about
it).

Normally output is not written to stdout (that is associated with a tty) until
a newline is sent.  When stdout is redirected to a file, it is buffered for 
a full stdio block.  Using setbuf() turns off all buffering.



-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
                                                Sterling, VA 22170