Print on terminal and into file simultaneously?

Question

I have a shell script that greps some data.. I want to print the result into a file, but doing that prevents the result being displayed on the terminal. Is there a way that

Answer 1

Pipe your output to the tee command.

Example:

[me@home]$ echo hello | tee out.txt
hello
[me@home]$ cat out.txt 
hello

Note that the stdout of echo is printed out as well as written to the file specified by thr tee command.