Redirecting stdout and stderr
ls > file – redirect output to file
ls 2> err – redirect error to file named err
ls 2>&1 file – redirect error to where output is going to file named file
ls 1>&2 file – redirect stdout to stderr to file named file
ls > file 2> err – redirect output to file and error to file named err
exec 2> std.err – Redirect all error messages to file named std.err