Following four commands can be used to get a list of local devices which are online. They provide different types and format of informatione. Thank you rpi444from the raspberry Forum for the list of commands.
sudo nmap -sP 192.168.???.0/24 -oG - | grep -i upHost: 192.168.xx.1 (router) Status: Up
Host: 192.168.xx.2 (repeaterix1) Status: Up
Host: 192.168.xx.3 (repeaterix2) Status: Up
Host: 192.168.xx.10 (raspifix) Status: Up
Host: 192.168.xx.11 (seafile) Status: Up
Host: 192.168.xx.103 (S3) Status: Up
Host: 192.168.xx.138 (raspberrypi) Status: Up
Host: 192.168.xx.113 (ThinkPad) Status: Up
# Nmap done at Sun Nov 1 13:24:45 2015 -- 256 IP addresses (11 hosts up) scanned in 19.41 seconds
sudo arp-scan -vN -I wlan0 192.168.???.0/24Interface: wlan0, datalink type: EN10MB (Ethernet)Starting arp-scan 1.8.1 with 256 hosts (http://www.nta-monitor.com/tools/arp-scan/)
192.168.xx.1 xx:65:11:5c:01:xx (Unknown)
192.168.xx.2 xx:c7:a6:dd:77:xx (Unknown)
192.168.xx.3 xx:25:06:7d:97:xx (Unknown)
192.168.xx.10 xx:27:eb:3c:94:xx (Unknown)
192.168.xx.11 xx:27:eb:d6:a6:xx (Unknown)
--- Pass 1 complete
--- Pass 2 complete5 packets received by filter, 0 packets dropped by kernel
Ending arp-scan 1.8.1: 256 hosts scanned in 1.305 seconds (196.17 hosts/sec). 5 responded
sudo fping -aAnqs -g 192.168.???.0/24 -r 1repeaterix1 (192.168.xx.2)
repeaterix2 (192.168.xx.3)
raspifix (192.168.xx.10)
seafile (192.168.xx.11)
ThinkPad (192.168.xx.113)
hama (192.168.xx.104)
S1 (192.168.xx.107)
S3 (192.168.xx.103) 254 targets
9 alive
245 unreachable
0 unknown addresses 245 timeouts (waiting for response)
499 ICMP Echos sent
9 ICMP Echo Replies received
400 other ICMP received 0.10 ms (min round trip time)
790 ms (avg round trip time)
2602 ms (max round trip time)
13.293 sec (elapsed real time)
sudo nmap -sP -R --dns-servers 192.168.???.1 192.168.???.0/24 | egrep -o '([[:xdigit:]]{2}[:-]){5}[[:xdigit:]]{2}'xx:C7:A6:DD:77:xx
xx:25:06:7D:97:xx
xx:27:EB:3C:94:xx
xx:27:EB:D6:A6:xx
xx:21:C0:72:19:xx
xx:33:4C:41:63:xx
xx:07:F9:35:F0:xx
xx:27:EB:B4:E8:xx