This command fetches the list of "best frequencies" from
http://pskreporter.info/cgi-bin/psk-freq.pl and calls the
main.set_frequency XML-RPC command.
Optional arguments can be given to select the frequency and override the
grid square, e.g.:
pskrqsy JO 1
uses the second frequency from the list for grid square JO. The defaults
are to use the first frequency (index 0) with no specific grid square,
which psk-freq.pl then estimates using IP address geolocation.
Here is how to change to the best frequency every 15 minutes:
while :; do fldigi-shell -c pskrqsy; sleep 900; done