To search files of a specified name (mysearchterm) in the path, use:

$ locate mysearchterm

Or do a comprehensive search for all files irrespective if they are in the path, use:

$ find / -name mysearchterm

To search a term in files, use grep instead:

$ grep -r -e mysearchterm *

To find out any open ssh ports online, use nmap. It can be used to verify that a firewall is not blocking ssh, when troubleshooting connectivity issues in a host.

nmap has an option to ignore the host lookup, and generate a list of open ssh ports. The command is:

  nmap -P0 -sS -p 22 72.32.103.0/24 

where:

To see disk usage for current directory:

$ du -h

To see disk free:

$ df -h