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Questions tagged [control-characters]

Control characters are non-printing characters used to send signals to the output terminal.

Control characters are generally non-printing characters that are used to send signals to the output terminal.

More information is available on Wikipedia.

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What are carriage return, linefeed, and form feed?

What is the meaning of the following control characters: Carriage return Line feed Form feed
ashna
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What are the file/group/record/unit separator control characters and their usage?

Unicode defines several control characters from ASCII. http://www.unicode.org/charts/PDF/U0000.pdf I see many control characters are widely used but I really don't see where "information separators" are used. (U+001C~U+001F) What are they? What's…
eonil
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Finding the Values of the Arrow Keys in Python: Why are they triples?

I am trying to find the values that my local system assigns to the arrow keys, specifically in Python. I am using the following script to do this: import sys,tty,termios class _Getch: def __call__(self): fd =…
Newb
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Match non printable/non ascii characters and remove from text

My JavaScript is quite rusty so any help with this would be great. I have a requirement to detect non printable characters (control characters like SOH, BS etc) as well extended ascii characters such as Ž in a string and remove them but I am not…
Grant Doole
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Why is '\x' invalid in Python?

I was experimenting with '\' characters, using '\a\b\c...' just to enumerate for myself which characters Python interprets as control characters, and to what. Here's what I found: \a - BELL \b - BACKSPACE \f - FORMFEED \n - LINEFEED \r - RETURN \t…
PaulMcG
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Discretionary line break in HTML?

I'm looking for a way to specify where a line should break if it cannot fit on its line in a way similar to ­ (soft/discretionary hyphen), but with a space. I tried googling it but didn't get many relevant hits (mostly for InDesign despite…
Jakob Jingleheimer
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What does the "^@" mean in file?

Code: int fd; fd = open("fruit", O_WRONLY); write(fd, "apple", sizeof("apple")); close(fd); I compile it with $ gcc test.c -o test and run as $ ./test Then I open the fruit file, and I see the following in the file: apple^@ What does the ^@…
Ren
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Java: detect control characters which are not correct for JSON

I am reinventing the wheel and creating my own JSON parse methods in Java. I am going by the (very nice!) documentation on json.org. The only part I am unsure about is where it says "or control character" Since the documentation is so clear, and…
700 Software
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ASCII control character html input text

I'm trying to process input from a barcode scanner in a javascript browser app. The scanner output is a string of characters, which also contains at least one Group Separator character (ASCII 29). When I direct the input to i.e. notepad++, the…
user2007080
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What is the purpose of Unicode "Backspace" U+0008?

What is the purpose of the Unicode Character 'BACKSPACE' (U+0008) in programming? What applications can it be used for?
skibulk
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XmlTextWriter incorrectly writing control characters

.NET's XmlTextWriter creates invalid xml files. In XML, some control characters are allowed, like 'horizontal tab' ( ), but others are not, like 'vertical tab' ( ). (See spec.) I have a string which contains a UTF-8 control character that is…
Tom Lokhorst
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Removing control characters from a UTF-8 string

I found this question but it removes all valid utf-8 characters also (returns me a blank string, while there are valid utf-8 characters plus control characters). As I read about utf-8, there's not a specific range for control characters and each…
Xaqron
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Remove escape sequence characters like newline, tab and carriage return from JSON file

I have a JSON with 80+ fields. While extracting the message field in the below mentioned JSON file using jq, I'm getting newline characters and tab spaces. I want to remove the escape sequence characters and I have tried it using sed, but it did not…
user3792699
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What does PuTTY send when I press Enter key?

I am trying desperately to get a Bluetooth dongle working with my Arduino but I can't send it a command that it needs. I can use it when I plug it into my computer via a USB to UART chip and send the command (C) from PuTTY and then press Enter. The…
Sponge Bob
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Is there a faster way to clean out control characters in a file?

Previously, I had been cleaning out data using the code snippet below import unicodedata, re, io all_chars = (unichr(i) for i in xrange(0x110000)) control_chars = ''.join(c for c in all_chars if unicodedata.category(c)[0] == 'C') cc_re =…
alvas
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