Re: Does Linux has File Stream mapping support...?

[Jim Nance <jlnance@sdf.lonestar.org>]

On Fri, Nov 18, 2005 at 06:21:59PM +0530, Arijit Das wrote:
> Ye...I know of tee.
> 
> But the issue here is I have a HUGE Compiler (an Simulation tool)
> in which thousands of places there are "printf" statements to print
> messages to STDOUT stream. Now, a requirement came up which needs
> all those messages thrown to STDOUT also to be logged in a LOGFILE
> (in addition to STDOUT). Yes, this can be done through tee...but
> the usage model of the compiler doesn't leave that possibility open
> for me.

You have the source code for the compiler?  Put a call to something
like this at the beginning of main().  I'm leaving out the error handling,
you can write that ;)

void startlogging()
{
    pid_t tpid;
    int pfd[2];
    pipe(pfd);

    tpid=fork();
    if(tpid==0) {
        /* child process */
	close(0);
	dup2(pfd[0], 0);
	close(pfd[0]);
	close(pfd[1]);
	execl("/usr/bin/tee", "logfile");
    } else {
	close(1);
	dup2(pfd[1], 1);
	close(pfd[0]);
	close(pfd[1]);
    }
}

-- 
jlnance@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org