$ cfping.sh -h
$ usage: 
$      cfping.sh -c [-p 2000] [-s 5] [-g 1] [-m 500]
$         -c     ping [fping] all cloudflare ips to find the best ip
$         -p <x> sets the time in milliseconds that fping waits between successive
$                packets to an individual target (default is 2000, minimum is 10)
$         -s <x> set the number of request packets to send to each target (default is 5)
$         -g <x> the minimum amount of time (in milliseconds) between sending a
$                ping packet to any target (default is 1, minimum is 1)
$         -l     show cloudflare ip location
$         -m <x> you may want to use this according to system resources limit 
                 larger number faster result (default is 500)

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$     cfping.sh -d [-L https://domain.com/xxx] [-N 100] [-P 10] [-I ip]
$         -d     speed test (default testing best 100 IPs unless -I used)
$         -L <x> set the file link to test (default: https://speed.cloudflare.com/__down?bytes=100001000)
$                the domain of this link must have cname record on cloudflare
$         -N <x> set the number of IPs to test (default is 100)
$         -P <x> set the parallel number of speed test (default is 10)
$         -I <x> specify an ip to test

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$     cfping.sh [options] <start> <end>
$         -n <x> set the number of addresses to print (<end> must not be set)
$         -f <x> set the format of addresses (hex, dec, or dot)
$         -i <x> set the increment to 'x'
$         -h     display this help message and exit
$         -v     display the version number and exit