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Re: null-terminated vs. nul-terminated (was: Re: CVS commit: src/lib/libc/gen)

On Sat, Mar 26, 2022 at 9:53 AM Roland Illig <> wrote:
Am 24.03.2022 um 02:55 schrieb David H. Gutteridge:
> Module Name:  src
> Committed By: gutteridge
> Date:         Thu Mar 24 01:55:15 UTC 2022
> Modified Files:
>       src/lib/libc/gen: popen.3
> Log Message:
> popen.3: minor spelling, grammar, style, and xref tweaks
> To generate a diff of this commit:
> cvs rdiff -u -r1.22 -r1.23 src/lib/libc/gen/popen.3

The term "null-terminated string" is quite common when talking about C.
  In contrast, the word "nul" in "nul-terminated" always reminds me of
the character abbreviation in ASCII, which has a narrower scope than C.
  I prefer to keep "null-terminated" here.

The standard uses "null-terminated" and "null character" (see Character Sets section 5.2.1 (from the C2x draft, but this term dates back to C89):
"A byte with all bits set to 0, called the null character, shall exist in the basic execution character set; it is used to terminate a character string."
I couldn't find the definition for null-terminated though. This is different than the NULL #define

Not to be confused with the all zeros ASCII charater, whose mnemonic is NUL, which is where some pressure to use NUL terminated comes from. I agree that it's usage is narrower and really only relevant for certain ASCII and ASCII-derived character sets, which is why the standard chose the spelling it did.

Since all the 'C' standards[*] use "null-terminated" and "null character", it's likely best to use that terminology because there is a source of truth for its definition in case of ambiguity or doubt.


[*] I've not gone the extra mile and checked to see if K&R used this phrase, to be honest.

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