From what I am familiar with from the Linux world, the method does not appear to be 100% bulletproof. Essentially, the "diff" program (e.g. http://www.die.net/doc/linux/man/man1/diff.1.html) is used to create a "patch" file by comparing the old and new source. Then the "patch" program (e.g. http://www.die.net/doc/linux/man/man1/patch.1.html) can be used to apply the changes to another copy of the old source.
The person who runs the "diff" program must ensure that the "context" parameter specifies enough lines to ensure there are no ambiguities. Problem is, there is no guarantee that ambiguities won't still exist in different versions of the old source. I've seen claims that a particular patch will apply to multiple versions of a target program, but usually, the patch is documented as being applicable only to a specific version. At 08:37 AM 7/31/2006, Clark Morris wrote: >On 30 Jul 2006 12:12:42 -0700, in bit.listserv.ibm-main you wrote: > >>john gilmore wrote: >>> I am as aware as EJ is of the historical use that has been made of SNs >>> to maintain source programs, and I mentioned this role for them >>> explicitly in the post he comments upon. We differ about the >>> desirability of continuing to use them. So be it. >> >>Don't misunderstand me! We do *not* differ about the desirability of >>continuing to use sequence numbers. Personally, I don't like them. I >>prefer "unnumbered" source for programs not distributed to customers. >> >>My objection was to your assertion that the use of sequence numbers is >>now 'obsolete'. That would be a valid statement only if a viable >>alternative to their use for source-maintained programs existed. >>Unfortunately, one does not. > >How do the various source maintenance packages for other platforms >such as Unix handle the problem. I'm thinking of CVS and the various >Itegrated Development Environments. There are differential upgrades >and other techniques. I am not familiar with them but realize that I >am not familiar with most of the tools in the non-MVS environment. > ================================================== Art Celestini Celestini Development Services Phone: 201-670-1674 Wyckoff, NJ ============= http://celestini.com ============= Mail sent to the "From" address used in this post will be rejected by our server. Please send off- list email to: ibmmain<at-sign>celestini<dot>com. ================================================== ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
