What does this shell command mean “exec 3>&1 > >(logger -t ”OKOK“)”

Question

I've found the following bash command in some source code.

exec 3>&1 > >(logger -t "OKOK")

What does it exactly mean?

As far as I know, it redirects those log to the syslog.

However, What is 3>&1 ?

I have never seen a file descriptor of 3 before.

Answer 1

unusual indeed, but it does exist:

Each open file gets assigned a file descriptor. The file descriptors for stdin, stdout, and stderr are 0, 1, and 2, respectively. For opening additional files, there remain descriptors 3 to 9 . It is sometimes useful to assign one of these additional file descriptors to stdin, stdout, or stderr as a temporary duplicate link. This simplifies restoration to normal after complex redirection and reshuffling

Find out more on the IO redirection page .

Answer 2

From this line on, everything printed to STDOUT will be processed by logger . The original STDOUT has been saved in fd3, so you can later (if needed) restore the normal STDOUT. See Advanced BASH Scripting Guide for details.