sh command: exec 2>&1

Question

What will this command do?

exec 2>&1 

Answer 1

It ties standard error to standard out

the 2 is stderr and 1 is stdout. When you run a program, you'll get the normal output in stdout, but any errors or warnings usually go to stderr. If you want to pipe all output to a file for example, it's useful to first combine stderr with stdout with 2>&1.