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| From | Bartc <bc@freeuk.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Program to cipher a text, new thread, fresh one |
| Date | 2015-10-31 18:14 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <n130a5$ob3$1@dont-email.me> (permalink) |
| References | <8465675b-8538-4031-a5b7-d5ddba34197d@googlegroups.com> <1e1a0897-ba67-47b3-b778-0bc03f8b098b@googlegroups.com> <87oaffb4z9.fsf@bsb.me.uk> <n12oak$mom$1@dont-email.me> <8737wraqhw.fsf@bsb.me.uk> |
On 31/10/2015 17:37, Ben Bacarisse wrote: > Bartc <bc@freeuk.com> writes: > >> On 31/10/2015 12:24, Ben Bacarisse wrote: >> I tried to make it do the same encoding as yours, but there is a >> difference which might be a bug in your code, or a lack of >> understanding on my part: lower case strings are encoded differently >> from the same upper case input. >> >> So with key "ABC", then your program encodes "AAA" to "ABC", but "aaa" >> to "acb" (after restarting). (I assume that key "AAA..." having no >> effect is intentional.) > > That would be a bug, but I can't reproduce it. I've checked with the > code I posted (in case I posted something other that the last version), > and it seems to work as expected: OK, it's to do with the isalpha() function; some libraries in Windows return 1 or 2 for an alpha character (for upper or lower case presumably), and you use that to step along the key string. (So in Windows, it steps twice along the keystring for a lower case input. In Linux it stepped just once.) The specs for isalpha() just say it returns non-zero if test is true. > >> Anyway, in mine other differences are: >> >> * Requires ASCII (this is checked for) > > It's not entirely clear what ASCII means. You assume some things about > the letters (they they are contiguous) and you assume that no char > values are negative. Is that what you mean? Some encodings that some > people would call ASCII have negative characters. ASCII codes go up to 127. But the values of interest are 65 to 90, and 97 to 122, which are always going to be positive. >> * Is line-based, with lines limited to 500 characters. > > Why? It seems to complicate the program. To give an idea of what it looks like. A bit more complicated, but far more flexible. So I can grab an input string (from the console, file, data in a program or just construct it), and then do whatever I want with it including encoding or decoding, or reverse the string first and then encode. That's a lot harder if the input is trickled in a character at a time. >> (Yours also >> seemed to be line based, in that after pressing Enter, you got the >> encoded string, then it waited for another line, but that was an >> illusion. Strange though because after entering what you thought was >> the same line of input, you got a different encoding! > > I don't know what this means but my program is not line-oriented at all. > It sounds like you had some trouble running it. It's the simplest form > of filter, if that helps you work out how to test it. I ran it on Windows and Linux and they were the same (apart from the isalpha thing). Transcribed manually: ...$ ./a.out ABC LINE1 LJPE1 LINE2 MKNF2 LINE3 NIOG3 ^Z ... Stopped The input was LINE1 Enter, LINE2 Enter, LINE3 Enter. The characters are shown as I type, then as I press Enter, the encoded line is displayed, then it sits waiting for more input. It does look remarkably like it's reading a line at a time, outputting the encoding, then waiting for the next. Except the keystring is not reset and that gives confusing results. (Actually that was why I put a line-reading loop into my version!) -- Bartc
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Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 08:23 -0700
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-10-30 15:39 +0000
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 09:33 -0700
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 09:33 +0000
Re: Program to cipher a text, new thread, fresh one Mark Storkamp <mstorkamp@yahoo.com> - 2015-10-30 11:17 -0500
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 09:32 -0700
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 09:38 +0000
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-10-30 10:55 -0600
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 10:07 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-01 10:42 +0000
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 11:35 +0000
Re: Program to cipher a text, new thread, fresh one James Kuyper <jameskuyper@verizon.net> - 2015-11-01 08:33 -0500
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-01 16:09 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-11-02 12:43 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-02 13:25 +0000
Re: Program to cipher a text, new thread, fresh one Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 06:13 -0800
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-11-01 12:26 -0800
Re: Program to cipher a text, new thread, fresh one supercat@casperkitty.com - 2015-11-01 07:59 -0800
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-02 13:48 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-11-02 14:06 +0000
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-02 14:51 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-11-02 15:48 +0000
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-02 16:00 +0000
Re: Program to cipher a text, new thread, fresh one asetofsymbols@gmail.com - 2015-11-03 01:40 -0800
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 11:16 +0000
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 05:21 -0600
Re: Program to cipher a text, new thread, fresh one asetofsymbols@gmail.com - 2015-11-03 03:41 -0800
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 11:53 +0000
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 05:57 -0600
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 12:48 +0000
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-04 09:09 +0100
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-04 09:37 +0100
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-11-04 07:09 -0800
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 05:53 -0600
Re: Program to cipher a text, new thread, fresh one asetofsymbols@gmail.com - 2015-11-03 04:29 -0800
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 06:42 -0600
Re: Program to cipher a text, new thread, fresh one Geoff <geoff@invalid.invalid> - 2015-11-01 08:07 -0800
Re: Program to cipher a text, new thread, fresh one Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-02 02:26 -0800
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-06 07:53 +0100
Re: Program to cipher a text, new thread, fresh one Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-07 10:01 -0800
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 10:50 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 10:53 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-30 11:52 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 12:12 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-30 21:05 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 23:58 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-31 03:09 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 03:47 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-31 11:42 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-30 12:04 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 12:10 -0700
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-10-30 13:17 -0600
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 00:04 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 00:25 -0700
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-10-30 12:34 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 21:49 -0700
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-10-31 13:18 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 00:29 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 01:12 -0700
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 12:24 +0000
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 06:11 -0700
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-10-31 15:58 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 17:37 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-10-31 18:14 +0000
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-10-31 13:29 -0700
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 20:35 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 20:32 +0000
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-04 09:50 +0100
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