I need my website to generate a pdf file. I was planning on using PDFlib. When I try install it through the PEAR graphic interface, I get the error message "sh: phpize: command not found". Does anyone have any suggestions?
As noted by Marc B, you should have in your system a package containing the files needed for building PHP extensions (php-devel, usually).
On my Centos system you should type this command as root in a terminal:
yum install php-devel
This should work on Red Hat and Fedora, by the way.
On Debian or Ubuntu the command is slightly different:
sudo apt-get install php5-dev
If you want to start a terminal, the steps required depend on your desktop environment. Usually on Ubuntu users get Unity installed, so:
Dash -> More Apps -> Accessories -> Terminal
On Gnome3:
Applications menu -> Accessories -> Terminal
The keyboard shortcut is the same on both environment: Ctrl + Alt + T .
For other DEs take a look at this doc: https://help.ubuntu.com/community/UsingTheTerminal