[from the TCP/IP acronym 'Packet INternet Groper', prob. originally contrived to match the submariners' term for a sonar pulse]
1. n. Slang term for a small network message (ICMP ECHO) sent by a computer to check for the presence and aliveness of another. Occasionally used as a phone greeting.
2. vt. To verify the presence of.
3. vt. To get the attention of. From the UNIX command 'ping(1)' that sends an ICMP ECHO packet to another host.
4. vt. To send a message to all members of a mailing list requesting an ACK (in order to verify that everybody's addresses are reachable).
"We haven't heard much of anything from Geoff, but he did respond with an ACK both times I pinged jargon-friends."
The funniest use of 'ping' to date was described in January 1991 by Steve Hayman on the USENET group comp.sys.next. He was trying to isolate a faulty cable segment on a TCP/IP Ethernet hooked up to a NeXT machine, and got tired of having to run back to his console after each cabling tweak to see if the ping packets were getting through. So he used the sound-recording feature on the NeXT, then wrote a script that repeatedly invoked 'ping(8)', listened for an echo, and played back the recording on each returned packet. Result? A program that caused the machine to repeat, over and over,
"Ping... ping... ping..."
as long as the network was up. He turned the volume to maximum, ferreted through the building with one ear cocked, and found a faulty tee connector in no time.