Hello world and hello Texas from Database

Install VistA with something like Astronaut. Get to a Mumps prompt: choose item 3 if you are using VistA Commander. MUMPS>write "hello world" hello world MUMPS>write "hello " write $P(^DIC(5,48,0),"^",1) hello TEXAS MUMPS>write "hello ",$$GET1^DIQ(5,48,0.01,,,"ZERROR") hello TEXAS

What the first hello TEXAS line does:


 * Invokes the Mumps function $P[iece], which is similar to but not exactly like the substring command in many other languages.
 * The ^ indicates that this is not a local variable; Mumps will look for a global stored on disk and visible to other users.
 * The global DIC holds the File of Files, but ^DIC with the subscript 5 says to look in file 5 (The STATE File)
 * The ^DIC(5, is followed by a 48, which means entry 48 in the STATE File.
 * The ^DIC(5,48, is followed by 0 because the NAME Field is stored in node 0 and the first piece.
 * Then $P uses the ^ in this case as a delimiter, and returns the first piece.
 * Since ^DIC(5,48,0)="TEXAS^TX^48^^1^1", MUMPS writes "TEXAS".

What the second hello TEXAS line does:

& the first argument is the number of the file as the source of data.
 * invokes a FileMan function named $$GET1^DIQ which does the same thing as the first hello TEXAS line.