On Friday, 2 April 2021 at 05:01:27 UTC, rikki cattermole wrote:
>
> On 02/04/2021 5:51 PM, mw wrote:
>> Then how can I construct `t`? to make this assertion true:
>> 
>>     assert(t == "head-abc-tail");  // failed!
>
> Slice it.
>
> string t = text("head-", s[0 .. 3], "-tail");
>
> http://ddili.org/ders/d.en/slices.html

This is just an example, what if the exact length is not known statically, is there a functions to trim the `\0`s?

On Fri, Apr 02, 2021 at 05:05:21AM +0000, mw via Digitalmars-d-learn wrote: [...]
> This is just an example, what if the exact length is not known statically, is there a functions to trim the `\0`s?

What about `s.until('\0')`?

Example:

	auto s = "abc\0\0\0def";
	auto t = "blah" ~ s.until('\0').array ~ "boo";


T

-- 
What do you call optometrist jokes? Vitreous humor.

On Fri, Apr 02, 2021 at 05:05:21AM +0000, mw via Digitalmars-d-learn wrote: [...]
> This is just an example, what if the exact length is not known statically, is there a functions to trim the `\0`s?

Another way, if you want to avoid the extra allocation, slice the static array with .indexOf:

	s[0 .. s.indexOf('\0')]

should give you the initial segment up to the first null.


T

-- 
Questions are the beginning of intelligence, but the fear of God is the beginning of wisdom.

On 02/04/2021 6:10 PM, Computermatronic wrote:
> On Friday, 2 April 2021 at 05:02:52 UTC, mw wrote:
>> Ahh, I got what I see (from writeln) is not what get string here ;-)
>>
>> And I just tried:
>>
>> string t = text("head-", strip(s), "-tail");
>>
>> It's the same behavior.
>>
>> So how can I trim the leading & trailing `\0` from the static char array?
> 
> strip only removes whitespace, not null characters. You'd have to do something like
> ```d string t = cast(string)text("head-", s, "-tail").filter!`a != '\0'`().array;```
> I would assume there would be a better way, but I haven't been able to find a dedicated function for stripping null chars in std.

If you know it has null terminators you can use fromStringz.
But this is a case of you should store the length.

On Friday, 2 April 2021 at 05:18:49 UTC, H. S. Teoh wrote:
> On Fri, Apr 02, 2021 at 05:05:21AM +0000, mw via Digitalmars-d-learn wrote: [...]
>> This is just an example, what if the exact length is not known statically, is there a functions to trim the `\0`s?
>
> What about `s.until('\0')`?
>
> Example:
>
> 	auto s = "abc\0\0\0def";
> 	auto t = "blah" ~ s.until('\0').array ~ "boo";

Finally, I'm using:

https://run.dlang.io/is/651lT6

    string t = text("head-", s[].until('\0').array, "-tail");

It works for both s = "abc" (with \0), and "abcdef" (full 6 chars, indexOf will return -1 for bad range index).


Thank everyone who helped.