PHP sessions are global variables that transmit data stored during web visits across multiple pages, i.e., they are not lost when moving from one page to another. PHP accomplishes this by assigning unique IDs to visits (sessions) and creating files in the server-side file structure associated with those IDs in which it stores the data required for the session. The system places these files in a specific directory, usually tmp, which is normally deleted by the garbage collector after a specified time. However, the situation is sometimes not so obvious. This is because if the PHP environment on the server changes, the garbage collector may not be able to delete these obsolete, unnecessary session files. In this description, we will look at how we can use our own solution to ensure that these session files are deleted when the default cleaning system cannot remove them.

When programming, it is important that when we write a program that performs a certain task, our code should be prepared for several possibilities, variations and, if possible, parameterized - with which we can make its operation fine-tuned. This is no different for shell scripts. In today’s example, we’ll look at how we can flexibly handle the parameters we get in our scripts, making it easier to create programs that are easier for others to use.

During programming, it is often necessary to use arrays, which can be used to store several values ​​at once, which can then be processed automatically in cycles. This is no different for Shell scripts. In this four-page description, we’ll look at several examples of how we can use array variables in different situations in our Shell scripts. On this page, we’ll learn how to create indexed arrays, load and read data into arrays, and see how to use indexed arrays in loops.

In this tutorial, we will introduce you to whiptail, how to display various dialog boxes in our shell scripts, such as info boxes, message boxes, yes / no question boxes, text entry boxes and text boxes to help make our programs convenient for our users.