MPE/iX - CI Programming for Stability

July 18, 2008 HP World '01 62
UDCs vs. scripts (cont.)
• maintenance / flexibility / security
• SETCATALOG opens UDC file, cannot edit without un-
cataloging file, but difficult to accidentally purge UDC file
• UDC commands grouped together in same file, easier to view
and organize
• UDC file can be lockword protected but users don’t need to
know lockword to execute a UDC
• scripts opened while being executed (no cataloging), can be
purged and edited more easily than UDCs
• scripts can live anywhere on system. Convention is to place
general scripts in a common location that grants read or
eXecute access to all, e.g. “XEQ.SYS” group
• if script protected by lockword then it must be supplied each
time the script is executed