The PHP Extension and Application Repository (PEAR) has a
Net/* hierarchy that includes a number of classes for interacting with the
network layer. One particularly handy class is Net_Ping,
which, as the name implies, lets you run a ping from PHP.

You use the ping() method to run a basic
network ping
. That method returns an associative array containing the raw
data and packet statistics
(Listing A).

Readable ping data

Most of us would probably prefer the output in a more readable
format. To this end, the Net_Ping class offers a
number of methods designed to extract specific subsets of data from the array in
Listing A. These include getTargetIp() for the IP address; getMin(), getMax(), and getAvg() for
response times; getLoss() for the number of lost
packets; getBytesTotal() for the total number of
bytes transmitted; and getRawData() for the raw
output of the ping command.

Consider the example in
Listing B, which demonstrates these
methods (and a few others) in action. There are three items of note in this
example code:

1. We’ve revised the script from our basic ping example to
make it more interactive. The domain name can now be retrieved from the user
through a form instead of being hardwired into the script.

2. The response returned by the remote host is broken down
using the methods listed previously and is formatted into a neat report. Look
in the script comments to see exactly what each method does, or run the ping
command at your shell prompt to gain a better understanding of what each field
means.

3. The setArgs() method is used to pass additional parameters to the ping
command. This method accepts an associative array of variable-value pairs. The
two important ones here are “size”, which controls the size, in
bytes, of the ping packets transmitted, and “count”, which controls
the total number of packets transmitted. The script above allows the user to
specify the latter variable through a form field.

More PHP network functions

There are other useful classes in the Net/* hierarchy
besides Net_Ping, including support for traceroute and DNS functions.