ObPedant ITYM "raises the question"; begging the question is something quite different.
Even on the same physical printer, "printable" depends on such things as UCS tables and font definitions. To add to the mess, many PC code pages have infected the code points reserved for control characters with other uses. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Charles Mills <charl...@mcn.org> Sent: Wednesday, December 4, 2019 5:03 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Misuse of the word hexadecimnal (Was RE: COPYING PDS TO PDS ...) It's true, "non-printable" begs the question of "what printer?" I have seen character sets that included little 2-character "hex" glyphs that could therefore "print" or represent any byte value. I work mostly in C++ so I tend to think in terms of the C library. The standard C library has a Boolean function isprint(). I just looked up the spec for that function and it is so self-referential as to be useless: Test for a printable character including space, as defined in the print locale source file and in the print class of the LC_CTYPE category of the current locale. (i.e., printable means printable). And I just looked up the Microsoft definition and it is even more convoluted and effectively useless. Still, I think "printable character" is useful: I think most people have a good general idea of what it means. But granted it is not so precise as, say, alphanumeric. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Tom Marchant Sent: Wednesday, December 4, 2019 10:52 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Misuse of the word hexadecimnal (Was RE: COPYING PDS TO PDS ...) On Wed, 4 Dec 2019 10:01:36 -0800, Charles Mills wrote: >"Non-printable" (or sometimes non-alphanumeric/national) is the >word people are looking for. I disagree. "non-printable" is a term that has little meaning. Even if you mean "non-printable using a TN print train", for example, that is only a subset of the 256 possible values in a byte. The point of using a term like "any hexadecimal character" is to indicate that all 256 possible values in the byte are acceptable. It could just as well be "a byte with any hexadecimal value", or "a byte with any binary value". -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
