"At some point, though, you want to do more, or you're
forced to do more. By that, I mean you have to work directly with
the file system of the server PHP is running on. You end up needing
to work with files on the file system, understand what processes
are running, or perform some other task.
"At first, you're content using commands like file() in PHP to
open files. At some point, though, the only way to get something
done is to be able to run shell commands on the server and get back
some type of output. For example, you might need to know how many
files live in a certain directory. Or you may need to know how many
lines have been written to a group of log files. Or you may need to
operate on those files to copy them to another directory or use
rsync to transport them to another location.
"In "Command-line PHP? Yes, you can!," Roger McCoy shows how to
use PHP directly from the command line -- no Web browser needed. In
this article, I approach the subject from the other point of view,
showing you how to integrate closely with underlying shell commands
and folding any return values into your interfaces and
processes."
