How do I write to a file and print to a terminal concurrently in Unix?

Question

I have a little bash function to log my Macports outputs to a file (since installs often spew little tidbits that are easy to lose in terminal noise), then I just cat the file to the terminal:

function porti {
    command sudo port install $@ >> $1.log 2>&1; cat $1.log
}

Is there a way to do this concurrently?

BTW I pass $@ to install but only $1 for the file name so that I can do something like:

porti git-gore +bash_completion

and only get the file git-core.log however someone else might prefer to include variants in the file name...

Answer 1

The usual solution is to use tee(1):

sudo port install $@ 2>&1 | tee -a $1.log

should do what you want