Editing Scanco User Instructions (section)

===Your First DCL Script===
Ever since Kernighan and Ritchie wrote the book "The C Programming Language", it has been custom to start with a program that prints the text "Hello, world" to the screen. Open a text editor (for example "EVE") and enter the text below.
<pre>
$! My First DCL Script
$ mymessage = "Hello, world"
$ WRITE SYS$OUTPUT mymessage
$ EXIT
</pre>
Now save the file as HELLO1.COM, and run it using <pre>$ @HELLO1.COM</pre>

Several things are happening in the above program:
*'''Comment !''': The exclamation mark can appear anywhere on the line, and everything following the mark will be treated as a comment. 
*'''Variable''': "mymessage" variable is populated with the string "Hello, world", which can be used in the rest of the script. 
*'''Command''' "WRITE" send text to various places, in this case to "SYS$OUTPUT", that is to the standard output (i.e. screen). 
*'''EXIT''' command tells the DCL interpreter that the script is done and we should exit.
*Commands in DCL are '''NOT case sensitive''', so the command "write sys$output mymessage" would produce the exact same result, but by convention we write commands in all uppercase.

*'''Special Comment !!''' automatically prints the contents of the comment to the screen/logfile. It is useful when you want to know what part of the script you are in.