todd@cincom.umd.EDU ("TODD AVEN") (01/21/88)
One of the lesser-known qualifiers for the DIFFERENCE utility is /SLP. The output of DIFF/SLP is a file of SUM/SLP commands and data, which can then be fed directly into EDIT/SUM using the /INPUT qualifier (I _think_ that's the right one). No special editing scripts or manual hacks are required. Many of us post software and/or updates, and of those many use DIFF to reduce network traffic. If we can get in the habit of posting SUM/SLP difference command files instead of plain-text differences, we all stand to gain by reducing human CPU-time as well. (Now for the Devil's Advocate...) While DIFF/SLP produces an SLP command file which requires nothing more complicated than the invocation of that editor, the difference file does not contain as much information as the ordinary difference output. In particular, SLP supports very basic operations: insert line(s) here, delete line(s) here, and replace line(s) here. Because of the nature of SLP commands, I see no real mechanism for maintaining synchronization during the edit. By that I mean that if the appropriate SLP action was to delete lines 20-23 and someone had edited the original file by adding a line before line 20, some of the wrong lines would be deleted. Everything is tied to a line's position in the file, so the user must guarantee that he is updating the correct file. Any comments/workarounds? Oh, yeah... The qualifier is /UPDATE=<diff file> now that I think about it. Please, if you *must* take me to task for being wrong about something here, be gentle -- I'm speaking off the top of my head (which seems to be located, along with the rest of me, on top o a soap box at the moment :-). Todd Aven the Software Sweatshop bitnet: TODD@UMCINCOM internet: todd@cincom.umd.edu ------
d2b@rayssd.ray.com (Donald A. Borsay) (02/06/88)
In article <8801220209.AA16725@ucbvax.Berkeley.EDU> "TODD AVEN" <todd@cincom.umd.edu> states the need to have a programatic way of applying source differences that have been posted. He goes on to say: >One of the lesser-known qualifiers for the DIFFERENCE utility is /SLP. >The output of DIFF/SLP is a file of SUM/SLP commands and data, which >can then be fed directly into EDIT/SUM using the /INPUT qualifier (I _think_ >that's the right one). No special editing scripts or manual hacks are >required. As to my surprize, our uVAX with all uVMS "groups" installed has an altered EDIT CLD, which doesn't have the /SLP qualifier. The SUMSLP image is present in SYS$SYSTEM, though. Don't know if this would put a wrench in using SLP... >Everything is tied to a line's >position in the file, so the user must guarantee that he is updating >the correct file. Any comments/workarounds? Yeh, that's why SLP is not suited for this application. From what I understand there was a good context diff program submitted to the Usenet comp.sources group which would do the trick. Anyone port it to VMS? -- Don |Raytheon Company, Submarine Signal Division, Portsmouth, RI Borsay |ARPAnet: d2b%rayssd.RAY.COM@a.cs.uiuc.edu |UUCPmail: {allegra, decvax!brunix, linus!raybed2}!rayssd!d2b