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

What the above hello TEXAS line does:

• Invokes the $P[iece] command, 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.
• DIC is the data dictionary, and the subscripts say to look in file 5, field 48, item 0.
• 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".