Scripting - Chapter 2: Basic Functions

Note: All of the commands we're about to see must be inserted between the POL_SetupWindow_Init and the POL_SetupWindow_Close commands.

Displaying a message

Here comes the command POL_SetupWindow_message:

Syntax:

POL_SetupWindow_message "Message" "Window title"

Example:

#!/bin/bash
[ "$PLAYONLINUX" = "" ] && exit 0
source "$PLAYONLINUX/lib/sources"
 
POL_SetupWindow_Init
 
POL_SetupWindow_message "Hello World!" "My first message"
 
POL_SetupWindow_Close
exit

This is what you will get:

PlayOnLinux Wizard My first message

Hello World!

Cancel

Next

You can now display a message. Congratulations.

A text zone

Do you want to ask the user a question? The POL_SetupWindow_textbox function was created for that purpose. Add the following code to your script:

Syntax:

POL_SetupWindow_textbox "Message" "Window title"

Example:

POL_SetupWindow_textbox "What is your name?" "Text zone"

We'll see in the next chapter how to retrieve the text that the user entered.

A question?

Do you want the user to be able to answer by yes or no? Then use this function POL_SetupWindow_question

Syntax:

POL_SetupWindow_question "Question" "Window title"

Example:

POL_SetupWindow_question "Do you like PlayOnLinux?" "My first question"

In the next chapter we will see how to retrieve the answer to the question.

A little menu

Just like for the two previous functions, you can create a menu for PlayOnLinux.

Syntax:

POL_SetupWindow_menu "Message" "Window title" "Available choices separated with the separator" "The separator"

The different entries must be separated by a single character separator, specified in the call; it should be provided as the last positional argument. The characters most often used for that are dash (-), pipe (¦), and tilda (~).

Example:

POL_SetupWindow_menu "What would you like to eat tonight?" "Tonight's menu" "Carrots|Potatoes|French-Fries" "|"

In the next chapter we will see how to retrieve the selected entry.

Select a file

You can ask the user to select a file from their computer in the following manner:

Syntax:

POL_SetupWindow_browse "Message" "Window title"

Example:

POL_SetupWindow_browse "Select installation program" "File selection"

In the next chapter we will see how to retrieve the selected file.

Introducing your application

This command is very important. It allows you to introduce the application to the user before they install it.

Syntax:

POL_SetupWindow_presentation "Name of the program" "Editor of the program" "Editor's site" "your pseudo" "Program's prefix (cf chapter 5)"

Example:

POL_SetupWindow_presentation "Mozilla Firefox" "Mozilla" "http://www.mozilla.com" "Script author" "MozillaFirefox"

Comment your code

The "#" symbol (also known as hashtag, hash, pound sign, etc.) tells Bash to ignore the text until the end of the line. Here's an example:

POL_SetupWindow_message "Hello" "Test"
# A nice comment
POL_SetupWindow_message "Goodbye" "Test"

You should comment your scripts as much as possible to improve their readability and help scripters in their validation task.

Previous: Chapter 1: Getting to know Bash

Next: Chapter 3: Variables