$ nmap -Pn -p993
imap.gmail.com |& grep -q 'Host is up'
&& { ... }
And of course someday the printed text will change and I'll have to edit
my scripts again! Oh well. :-/
Host is up wouldn't be right - you need to parse to see if the port is
listed as open or closed...
Something like:
nmap -Pn -p993
imap.gmail.com | awk '$1 ~ /993/ {print $2}' | grep open