topic Re: Bug in sprintf library function? in MCUXpresso General

Bug in sprintf library function?

Daan — Tue, 30 Nov 2021 16:35:30 GMT

If I run the following code:

int len; char buf[10]; len = sprintf(buf, "%d", -1)); // len = 2: correct len = sprintf(buf, "%.15g", (double)-1)); // len = 2: correct len = sprintf(buf, "%1.15g", (double)-1)); // len = 1: incorrect len = sprintf(buf, "%.15g", (double)1000)); // len = 4: correct len = sprintf(buf, "%1.15g", (double)1000)); // len = 4 correct

Why is len 1 if %1.15g format is given? This should be 2. Other compilers like VS gives 2 as well.

I run this code on an i.MX RT1064, MCUxPressoIDE v11.4.0 Build 6237

Re: Bug in sprintf library function?

ErichStyger — Tue, 30 Nov 2021 16:53:16 GMT

just for the sake of clarity: what library are you using?

RedLib, Newlib or newlib-nano (which I would recommend)?

Erich

Re: Bug in sprintf library function?

ErichStyger — Tue, 30 Nov 2021 18:16:20 GMT

FYI, I ran your examples with newlib-nano, with float in printf/scanf enabled, and it gave the expected results for me. I suggest you check your library settings. But I have used 11.4.1 in case this makes a difference.

I hope this helps,

Erich

Re: Bug in sprintf library function?

Daan — Wed, 01 Dec 2021 07:12:31 GMT

Thanks for your reply Erich! I run newlib-nano as well. I will check the changes in the new version