Of all the curious and wonderful Unix words that have seeped into the English language, perhaps the most common is ping. I hear it used all the time.

ping stands for Packet InterNet Groper. It was developed in the early years of networking to test whether a system was available or not. So at the command line you typed ping followed by a hostname or IP and see whether or not anything is there:

ping 127.0.0.1

The above command tests the local host, which generates results similar to this:

PING 127.0.0.1 (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.050 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.050 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.119 ms
^C
--- 127.0.0.1 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.050/0.073/0.119/0.033 ms

On a PC with Windows (at the command prompt), only four packets are sent. On my Mac, in the Terminal program, I typed Ctrl+C to halt the output. Otherwise, the output indicates that a 64-byte packet was sent to the host, received, and returned. The total transit time is also listed.

Regardless of the acronym (and typical of Unix commands), the name really comes from the ping used by submarines to measure distance: The sound of the ping made by one sub echoes off another sub or body and the echo is timed to calculate distance. That acoustical definition also applies to the computer ping command as well.

For example, the round trip time indicated by a ping packet generally tells you how far away or, more specifically, how efficient the connection is between your computer and the host. For the localhost, the value is as fast as can be measured because it’s your own computer. But if you ping a system on another continent, the time difference might be measured in seconds, not milliseconds.

And sometimes the host cannot be reached at all. In that case, you see a timeout displayed instead of a time value. The timeout isn’t an error by the ping program, it simply means the host is either offline or simply cannot be reached. And some hosts disable the ping port, so that could also be the case.

In colloquial conversation, people may use the verb ping meaning to contact someone or send a reminder. Most frequently, however, ping is used in online gaming to refer to the connection speed of a host.

For example, you join an online game and you see a list of players. Next to each player is their score and other information, including a ping rating. That value is similar (if not identical) to the ping value for the host. So a player with a low value has a faster, better connection than a player with a higher ping value. In fact, the lower the value the more responsive the game can be.

And no, to answer your obvious question. There is no pong command. Not yet, at least.