Scrupp: Getting Started

Architecture

architecture of applications using Scrupp

This figure shows the architecture of an application created with Scrupp. The whole development happens on the right side using Lua.

Command Line Interface

At the beginning, Scrupp tries to run a Lua file which is chosen depending on the command line arguments.

No command line arguments
```
$ scrupp
```
In this case Scrupp tries to open the file main.lua in the directory where the Scrupp executable is located. This directory will also be the working directory of the script. However, it is not possible to give extra arguments to the Lua file, yet.
A Lua file as argument
```
$ scrupp -e <Lua file> arg1 arg2 ...
```
Scrupp adds the directory that contains the Lua file to the search path. Every attempt to open a file (images, sounds, music, fonts, other Lua files) will result in a search for it in this directory. In case the file is not found there it will be searched in the directory of the executable. After that the Lua file is executed. Now it is possible to give extra arguments to the Lua file.
A directory as argument
```
$ scrupp <directory> arg1 arg2 ...
```
The directory is added to the search path and set as the working directory. Every file access results in a search in this directory at first. Only if it is not found there the file will be searched in the directory of the executable. Then Scrupp tries to execute main.lua which should be located inside this directory. Now it is possible to give extra arguments to the Lua file.
A zip archive as argument
```
$ scrupp <zip archive> arg1 arg2 ...
```
The archive is added to the search path. The directory containing the archive becomes the working directory. Every file access results in a search in this archive at first. The directory of the executable is searched after that. Then Scrupp tries to execute main.lua which should be located inside this archive. It is possible to give extra arguments to the Lua file.

Script Arguments

Before running the Lua file, Scrupp collects all command line arguments in the global table arg. The name of the chosen Lua file, directory or archive becomes the element at index 0 in that table. Additional arguments are stored in index 1, 2 and so on. Any arguments before this name (name of the executable, the options) go to negative indices. The script can access these arguments by using arg[1], arg[2], etc. or the vararg expression '...'.

-- print the name of the script
print("name of the script:", arg[0])

-- print the number of arguments to the script
print("number of arguments:", select('#', ...) )

-- print all arguments
print("arguments:",...)

-- this prints the first argument
print("Argument 1: ", arg[1] or "none")

-- exiting Scrupp
game.exit()

Just save this example code in a file called argtest.lua and run

$ scrupp -e argtest.lua arg1 arg2

This can be done with every example from the manual. To get started have a look at the General Functions, save the example in a file and run this file with Scrupp.