I would like to create a log file that records everything my program prints to the terminal, but I also want to be able to write verbose info to that log file which wouldn't get sent to the terminal. It was suggested to me to try the POSIX 'tee' command as such: 
#!/usr/bin/perl

open(STDERR,">&STDOUT");                        # Redirect IO
select(STDOUT); $| = 1;                           # Unbuffered output

# Set the path and format of the name for z_brian's log file
$logfileName = sprintf("$ENV{LTMP}/z_brian_%02d\_%02d\_%02d.log", $yea
+r, $mon, $mday);

# Write everything that goes to standard out also to the log file
open(STDOUT, "| tee -ai $logfileName");

# Open a file handle to that same log file to also write verbose info 
+to
open(my $LOGFILE, ">>", $logfileName) or die $!;

print "Welcome user!\n";
print $LOGFILE "log msg 1\n";
print STDOUT "out msg 1\n";
print $LOGFILE "log msg 2\n";
print STDERR "err msg 1\n";
print $LOGFILE "log msg 3\n";
print "out msg 2\n";
print $LOGFILE "log msg 4\n";
print "Goodbye user!\n";
print $LOGFILE "log msg 5\n";

[download]
This code does not work as I would like. The result on the terminal is correct except for STDERR (but I can live with that if needed). However, the log file displays all of the data I write to the log file before all the data I write to STDOUT, and I want to preserve the order so I can do 'tail -f' to see log file additions in real-time.

In reply to tee and log files by not-a-monk

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