Question

In this context, how does the specified field separator work?

awk -F\' '{print "conn kill "$2"\nrepair mailbox "$2" repair=1"}'

Answer 1

-F\' is using the single quote ' as the field separator.

Also the ' is being escaped by preceding it with a \ so that awk does not think of the ' as the beginning of the action part.

Alternatively you can enclose the ' in double quotes:

$ echo "foo'bar'baz" | awk -F\' '{print $1}'
foo
$ echo "foo'bar'baz" | awk -F"'" '{print $1}'
foo