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control character whose bits are all 0
This is not possible to do with Notepad, however, it can be done with a more advanced editor.
With Notepad++
Go to
Edit > Character Panelto show the ASCII Insertion Panel.Put the cursor where you want to insert the character.
Double-click the character (in the Character column) to insert.
With Notepad++
From HEX
- Type 00 00 00
- Select this text
- TextFX > TextFX Convert > Convert Hex to text
From Base64
- Type AA==
- Select this text
- Plugins > MIME Tools > Base64 Decode
The mapping is:
NUL -> AA=
NUL NUL -> AAA=
NUL NUL NUL -> AAAA
Hello everyone!
In C, strings (character arrays) are terminated by null character '\0' - character with value zero.
In ASCII, the NUL control code has value 0 (0x00). Now, if we were working in different character set (say the machine's character set wouldn't be ASCII but different one), should the strings be terminated by NUL in that character set, or by a character whose value is zero?
For example, if the machine's character set would be UTF-16, the in C, byte would be 16bits and strings would be terminated by \0 character with value 0x00 00, which is also NUL in UTF-16.
But, what if the machine's character set would be modified UTF-8 (or UTF-7, ...). Then, according to Wikipedia, the null character is encoded as two bytes 0xC0, 0x80. How would be strings terminated in that case? By the byte with value 0 or by the null character.
I guess my question could be rephrased as: Are null terminated strings terminated by the NUL character (which in that character set might be represented by a nonzero value) or by a character whose value is zero (which in that character set might not represent the NUL character).
Thank you all very much and I'm sorry for all mistakes and errors as english is not my first language.
Thanks again.
My output looked correct however the check50 said output was not a valid ASCII text. After googling I fixed it by adding the null character to the end of the output array.
I understand that the null character is how C tells where the string ends, however I still don't fully understand why it was needed for my program, since the output that I see still looks the same whether or not I have that character. Since my output is in a char array so C already knows the size of that array.
Is someone able to explain why adding this character was needed? Is it just something that the check50 checks arbitrarily to qualify it as "valid ASCII text"?
"NUL" is short for "NULL". Quoting ECMA-48, which lists all control characters as "8.3.xx acr - name":
8.3.88 NUL - NULL
Notation: (C0)
Representation: 00/00NUL is used for media-fill or time-fill. NUL characters may be inserted into, or removed from, a data stream without affecting the information content of that stream, but such action may affect the information layout and/or the control of equipment.
Now, about your question:
In wikipedia it says that the ASCII NULL character is called NUL.
This is not what Wikipedia says. It says the ASCII null (lowercase!) character is called NUL. "Null character" is a term that applies to all character encodings, "NULL character" is not.
Wikipedia is correct, as there is nothing wrong with referring to this character by its official acronym.
In comment 2962254, Matteo Italia states that the NULL character is not called NULL.
He is wrong about that.
here, the table in "Character groups", the name is "NULL", abreviated "NUL"
here NUL is an abreviation, not a name
These are both correct.
in answer 30121329: «NUL is the name given to the first ASCII character.»
This is technically incorrect, but for all practical purposes correct. The acronyms are better known than the official names, and I don't see much of a problem in treating those acronyms as names.
Yes, nul, is an abbreviation of null.
Not a particularly shortened version as it’s only shorter by one character, but as ASCII characters are limited to 3, so there isn’t much choice really.
The uppercase standard of NUL is a convention of ASCII, for example, TAB.