In a message dated 1/11/2007 1:22:34 P.M. Central Standard Time, [EMAIL PROTECTED] writes: >I would call this a user-hostile approach on MVS's part. Why would not a designer interested in producing user-accessible software, a system that would not have a reputation for being hostile, why would he not put a bit in the DSCB-1 that said whether or not the file had ever been opened and closed for output? And if the flag were not set, have open input put out a readable message that said "you can't open for input a file that has never been written"? Or at least to not attempt the impossible, reading a block length of zero, but instead to put out a "you can't read a block size of zero" message? The Format 1 DSCB is a legacy of ca. 1964 when it was designed. Back then, machines and bytes were far more expensive than people (which is why we had the Y2K crisis). Every bit of metadata was painstakingly parceled out, fields were overlaid and used for multiple purposes (the DCB may be the ugliest case of this), and user experience was minimal. Perhaps the part of IBM that designed QSAM was not so much user-hostile back then but rather user-unaware. I don't know for sure, but I would hope that VSAM, being a much later vintage access method, and which has oceans of bytes in a catalog structure in which to store metadata instead of a tiny DSCB, has a bit for your above-stated purpose. That sounds like a really good idea to me. Or there could be some other way to detect the condition of a file's never have been written into. One problem with this idea, though, is that some users will always try to read such a file the hard way; i.e., by not using the standard higher-level access method (e.g., VSAM) and will try to read it with a lower level access method than the one that is sensitive to the condition (e.g., EXCP), and then they must know how to recognize the condition. >A stupid, easy-to-commit error should not require the ability to decode CCW's and make inferential leaps to solve it. Absolutely agree big time beyond the max. Bill Fairchild
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