Timeline for Why are special characters such as "carriage return" represented as "^M"?
Current License: CC BY-SA 3.0
8 events
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| Jun 6, 2014 at 8:54 | comment | added | barlop | @JonHanna In the case of TCP, it uses SYN and ACK but not with those ascii codes of SYN-0x16(^V) and ACK-0x6(^F). TCP doesn't use that ASCII, it uses a single bit for SYN 0x002 and a single bit for ACK 0x010 And so any values with those bit set would indicate SYN and/or ACK. As for Printers DC1,DC3 and Associated Press and the AP-1312 that is an interesting case I see mentioned here too en.wikipedia.org/wiki/C0_and_C1_control_codes I suppose that counts but I wonder to what extent they are control characters if you can't make them with Ctrl - Maybe back in the day you could? | |
| Jun 6, 2014 at 2:11 | comment | added | wchargin |
@barlop You can do ^I for a tab in standard bash: type ls ~/^I^I and you should see all the folders in your home directory.
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| Jun 5, 2014 at 23:47 | comment | added | Jon Hanna | Associated Press still use ANPA-1312 which uses 1–4, 6 & 16 are used to start every TCP/IP connection. Modern printers (among other thigns) still use 17 & 19. Together with those you mention, we've quite a percentage of them covered without really trying. I'll grant you they aren't in heavy use, but they ain't dead either. | |
| Jun 5, 2014 at 23:25 | comment | added | barlop | @JonHanna Of course I don't mean they were meaningless(past tense).But R.Have been meaningless for decades i.e. they had their original meanings from eons ago,tech that no longer runs, are (most of the chars) meaningless today w/ current and even slightly old tech.n if any are being put to modern uses it's not many. There's a list here en.wikipedia.org/wiki/Control_character of ones in common use 0,7,8,9,10,11,12,13,127. 9/33 so the others (24 of them) u would either c very rarely or not at all as they r as dead as the antic unused out of use for decades machinery they were used on | |
| Jun 5, 2014 at 21:53 | comment | added | Jon Hanna | none of the control characters are meaningless. Many of them are unused in many contexts, but every single one has at least one meaning. | |
| Jun 5, 2014 at 18:30 | history | edited | barlop | CC BY-SA 3.0 |
added 243 characters in body
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| Jun 5, 2014 at 18:27 | comment | added | barlop | Most of the control characters are meaningless, but even some of those with meaning like Ctrl-I i'm not sure where you can just do Ctrl-I and get a tab. | |
| Jun 5, 2014 at 18:25 | history | answered | barlop | CC BY-SA 3.0 |