External Procedures

Invoking other DCL procedures:

$ @filespec


where “filespec” is ddcu:[dir]filename.ext

ddcu: default = current default device
[dir] default = current default directory
filename no default
.ext default = .COM

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DCL procedures can invoke other DCL procedures. These can be stand-alone procedures or subroutines of the procedure(s) which invoke them (“external” subroutines).

Each procedure invoked creates a new procedure level or “depth”. Symbols local to the current depth are available to all deeper procedures, but not above. Global symbols are available to all procedure depths.

Each procedure “inherits” the VERIFY condition of the one before it. If VERIFY is on, it stays on; if off, it stays off. Each procedure depth has its own “ON” condition and so can change error handling as it needs to using “SET [NO]ON” and/or “ON condition THEN statement”.