Example 1:

To run the date command from a Perl program, and read the output

of the command, all you need are a few lines of code like this:

open(DATE, "date|");

$theDate = <DATE>;

close(DATE);

The open() function runs the external date command, then opens

a file handle DATE to the output of the date command.

Next, the output of the date command is read into

the variable $theDate through the file handle DATE.

Example 2:

The following code runs the "ps -f" command, and reads the output:

open(PS_F, "ps -f|");

while (<PS_F>) {

($uid,$pid,$ppid,$restOfLine) = split;

# do whatever I want with the variables here ...

}

close(PS_F);