Thanks @Jonathan. Charles
-----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Jonathan Scott Sent: Wednesday, March 14, 2018 9:56 AM To: [email protected] Subject: Re: Two string instruction questions Ref: Your note of 14 March 2018, 08:51:22 -0700 Charles Mills wrote: > 1. Is there a machine instruction that will find one string within > another? That given "Now is the time" and "is" would find the "is" and > return a pointer to it? A machine instruction analog of Rexx POS? I'm not aware of any such instruction. You can use SRST to find a single character, and that can be used as part of a search algorithm. > 2. Searching the PoOp for such an instruction led me to CUSE. It does > not seem that CUSE could be used for this - is that correct? If I am > reading CUSE correctly, then given "Now is the time", "All is well" > and 2 or 3 would return the position of "is". Is my reading correct? > What would that be good for? What would be a reasonable real-world use? CUSE is very useful for creating an efficient representation of the differences between two versions of a record, for example to create a log record showing which bytes changed. It finds the end of a block of changed data, ignoring unchanged sequences which are too small to be worth representing as a separate section. To skip to the end of the unchanged data, CLCL or CLCLE can be used. Jonathan Scott HLASM, IBM Hursley, UK
