There is currently no facility for embedding Gamma source code into a stand-alone Gamma executable. However, it is possible to create a Gamma program which appears to be a stand-alone executable to the user. This is done by using the shell's #! directive at the top of the Gamma file. Simply include the line indicating the full path for your Gamma program, for example:

#!/usr/cogent/bin/gamma
	  

If using Gamma with Photon, you should use:

#!/usr/cogent/bin/phgamma
	  

Then change the permissions on the Gamma file to be executable. The Gamma file can now be run directly as if it were a stand-alone executable. The directive must appear as the first line of the program, and it must reference the actual Gamma executable, not a link.

The following example program will print the famous "Hello world" message to the screen:

#!/usr/cogent/bin/gamma

princ ("Hello world\n");		
	  

There is no requirement for a function named main. If a function with the name main is defined, then Gamma automatically starts to execute that function. Thus, the result of the following program:

#!/usr/cogent/bin/gamma

function MyPrint()
{
    princ ("Hello world\n");
}

function main()
{
    MyPrint();
}

MyPrint();
		

is that the function MyPrint will be executed twice.

Command line arguments can be passed to the Gamma program using the list variable argv. For more details see Tutorial I.