IO Redirection – Pipe and Log STDOUT Simultaneously

I want to see output of first command in terminal, and save the output of the second command in a file.

As long as you don't care whether what you are looking at is from stdout or stderr, you can still use tee:

myscript | tee /dev/stderr | grep -P 'A|C' > out.file

Will work on linux; I don't know if "/dev/stderr" is equally applicable on other *nixes.

If I understand what you're asking for I this will do. I'm using the commands ls ~ and tee as stand-ins for ./foo and bar, but the general form of what you want is this:

$ ( time ./foo ) |& bar

NOTE: The output of time is already being attached at the end of any output from ./foo, it's just being done so on STDERR. To redirect it through the pipe you need to combine STDERR with STDOUT. You can use either |& or 2>&1 to do so.

$ ( time ./foo ) |& bar

-or-

$ ( time ./foo ) 2>&1 | bar

Example

$ ( time ls . ) |&  tee cmd.log
cmd.log
file1
file2
file3
file4
file5

real    0m0.005s
user    0m0.000s
sys     0m0.001s

And here's the contents of the file cmd.log produced by tee.

$ more cmd.log 
cmd.log
file1
file2
file3
file4
file5

real    0m0.005s
user    0m0.000s
sys     0m0.001s