libclc-developers

[Libclc-developers] clc_ultostr(5)

[<bo...@me...>]

I found a few more bugs in this function. Below is a copy of the latest 
CVS version. Lesson learned: No more submissions without a test program? ;-)

#include <stddef.h>
#include <string.h>

#include "clc_assert.h"
#include "clc_string.h"

/* Copyright(c) 2003, Jan Engelhart (hir...@us...) */

/* Comments from boa:
  * The previous version was broken in several ways.
  * 1. We must place the result from ptr[0] and rightwards.
  *    If we don't and ptr[0] == '\0', nothing is printed.
  *    memmove fixes that.
  *
  * 2. The previous version wrote outside the buffer, I added (size - 1).
  */
int clc_ultostr(char *ptr, size_t size, unsigned long num, int base)
{
     const char *sym = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
     char* sp;

     clc_assert_not_null(clc_ultostr, ptr);
     clc_assert_arg(clc_ultostr, size > 1);
     clc_assert_arg(clc_ultostr, base >= 2 && base <= 36);

     /* Point to the last char in buffer */
     sp = ptr + size - 1;
     *sp = '\0';
     do {
         *--sp = sym[num % base];
         num /= base;
     } while (num > 0 && sp != ptr);

     if(num > 0)
         return 0;
     else if(ptr != sp)
         memmove(ptr, sp, size - (sp - ptr));

     return 1;
}

-- 
boa

Please join the libclc-developers list
at http://lists.sourceforge.net/lists/listinfo/libclc-developers

[Libclc-developers] Re: clc_ultostr(5)

[Jan E. <je...@li...>]

>I found a few more bugs in this function. Below is a copy of the latest
>CVS version. Lesson learned: No more submissions without a test program? ;-)

I was too lazy to download libclc for this machine ;)

>int clc_ultostr(char *ptr, size_t size, unsigned long num, int base)
>{
>     const char *sym = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
>     char* sp;

Hey your style ain't even consistent (char* and char *)

>     /* Point to the last char in buffer */
Prefering //

I once addressed that sp was startp, but that seems to be overlooked,
anyway it's fixed . in here.

>     sp = ptr + size - 1;
>     *sp = '\0';
>     do {
>         *--sp = sym[num % base];
>         num /= base;
>     } while (num > 0 && sp != ptr);
>
>     if(num > 0)
>         return 0;
>     else if(ptr != sp)
>         memmove(ptr, sp, size - (sp - ptr));

Other thing: when you said comp.lang.c shall approve functions,
I recall that they claimed about the topicality of libclc in there...
i think this list is fine for it.


- Jan Engelhardt

Re: [Libclc-developers] Re: clc_ultostr(5)

[<bo...@me...>]

Jan Engelhardt wrote:
> 
> Other thing: when you said comp.lang.c shall approve functions,
> I recall that they claimed about the topicality of libclc in there...
> i think this list is fine for it.
Not quite sure if I understand you 100%, but if I do...

I followed the topicality thread and I think that we should keep project 
related stuff out of c.l.c. Discussion of code, interfaces and design is 
OK to discuss in c.l.c. That seemed to be the majority opinion in the 
group.

This list is great for many purposes, and much better than c.l.c to 
discuss things, but c.l.c must make the final decision on
- what goes into the library
- the semantics of functions
- the implementation of functions

Some may see that as a limitation, to me it is our greatest advantage. 
Progress isn't the best doing it this way, but the quality is 
unbelieveable. :-)

Bjørn

Re: [Libclc-developers] Re: clc_ultostr(5)

[Hallvard B F. <h.b...@us...>]

Sorry about the empty message.

Jan Engelhardt writes:
>> int clc_ultostr(char *ptr, size_t size, unsigned long num, int base)
>> {
>>     (...)
>>     /* Point to the last char in buffer */
> Prefering //

C89 only supports '/**/'.  '//' is C99/C++.

>>     } while (num > 0 && sp != ptr);

        'while (num     && sp != ptr)' is enough.

>>     if(num > 0)
>>         return 0;
>>     else if(ptr != sp)
>>         memmove(ptr, sp, size - (sp - ptr));

Please memmove in either case.  Return 1 (or length of string) if no
truncation, 0 if there is a truncated result:

       if(ptr != sp)
           memmove(ptr, sp, size - (sp - ptr));
       return !num;

-- 
Hallvard

Re: [Libclc-developers] clc_ultostr(5)

[Hallvard B F. <h.b...@us...>]