stderr and stdout to file (sh / bash / csh / tcsh)

stderr and stdout to file

sh: (time date) > wa.txt 2>&1
bash: (time date) >& wa.txt or (time date) &> wa.txt or (time date) > wa.txt 2>&1
csh/tcsh: (time date) >& wa.txt

There are 3 file descriptors, stdin(0), stdout(1) and stderr(2) (std=standard).