CodeWarrior for MCU中的主题 Re: sscanf function fails CW 5.9 IDE

sscanf function fails CW 5.9 IDE

jmborchers — Thu, 17 Mar 2011 02:29:25 GMT

The function vsscanf(LIBDEF_ConstStringPtr ps, LIBDEF_ConstStringPtr format, va_list args) in the scanf.c library always fails.

Input:

int x;

int result;

result=sscanf("123","%d",&x);

result always returns 0 and x never has the value 123.

This is because:

if (*s++ == *format++) { /*lint !e931 the expression is safe */

in the function vsscanf line can never be true. The code then jumps to inputFailure

Why would the input string be compared against the format string? It doesn't seem to make any sense.

Re: sscanf function fails CW 5.9 IDE

CompilerGuru — Thu, 17 Mar 2011 11:38:10 GMT

First please always mention what CPU/derivative you are targeting, this board is for so different chips like a RS08 (does not have a stack) up to a Coldfire V1 (32 bit registers).

I'm guessing that there must be something wrong with your setup, for example not enought stack space, using the a library which is incompatible with the provided options, issues with the memory layout, ....

The line you are quoting is to match direct input (think of sscanf("Hello", "Hello")), so the code apparently did not parse the % first.

I would suggest:

- start with a fresh, wizard generated project.

- make sure you have enough stack space

- copy/paste your simple sscanf code into it

- make sure it compiles without warnings (implicit parameter declarations)

- if that fails, zip it and post the project it here.

Daniel

BTW: IDE 5.9 refers to the editor/development environment. Really does not narrow the possibilities down.

Re: sscanf function fails CW 5.9 IDE

CrasyCat — Thu, 17 Mar 2011 13:57:42 GMT

Hello

Additional question/note from CompilerGuru answer.

Make sure you include stdio.h in your project

CrasyCat

Re: sscanf function fails CW 5.9 IDE

Lundin — Tue, 22 Mar 2011 14:51:44 GMT

Why are you using sscanf() on a 8- or 16-bit microcontroller? I can't come up with any reason why one would do that.