php5cli runs PHP commands in a shell
PHP is a scripting language used on many websites. It allows a page to do “dynamic” things (such as changing a page’s appearance based on user input, time or date, etc.)
One of the things I do wtih php5cli (or php in the shell) is check a PHP script for errors. This saves you the trouble of running your PHP-based web page in a browser (which may have bad side effects). ??Bad side effects?? Sure, what if your page is supposed to overwrite a file, and then hits an error. It may erase a perfectly-good file. Ok, enough gloom and doom talk. Let’s say you wanted to check “myPHPscript.php” for errors. Run the following command in a shell to check it for errors before it runs/executes. The option is a lowercase L (l) not a digit.
php -l myPHPscript.php
Another good use of PHP in a terminal is to generate HTML code. There’s a certain frustration in coding up an entire web site, and then needing to go back and make a change across all your pages. A time (and headache) saver is to let PHP do the “heavy lifting” for you. What does this mean?
Basically, you set up a series of instructions for a script to follow. Then, based on your needs, you make the script “write” different output based on a variable whose value may change. Sometimes this involves changing the size of table cells, but it could apply to writing an entire series of web pages. It comes in way handy when you’re looping over database results (and deciding to print the 2nd line of an address to the page).
In summary, when you’d have to change the same attribute in many, many places, and change them a few times, manually finding the attribute (for example a web link), you don’t have to manually (not mention “tediously”) hunt for the item(s) you want to change. Install php5cli with Synaptic (or other) package manager. This installs any needed dependencies.