Difference between revisions of "Hello world and hello Texas from Database"

Revision as of 15:06, 10 February 2010

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

What the above 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".

@@ Line 10: / Line 10: @@
 * Invokes the [[MUMPS Functions $PIECE|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~|global]] stored on disk and visible to other users.
-* DIC is the [[Data Dictionary~|data dictionary]], and the subscripts say to look in file 5, field 48, item 0.
+* The global DIC holds the [[File Of Files~|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".