Re: generic strncpy - off-by-one error

Erik Andersen
2003-08-13T02:47:56Z

On Tue Aug 12, 2003 at 10:18:21PM -0400, Albert Cahalan wrote:
> You're all wrong. This is some kind of programming
> test for sure!
>
> Let us imagine that glibc has a correct version.
> By exhaustive testing, I found a version that works.
> Here it is, along with the test code:
>
> //////////////////////////////////////////////////////
> #define _GNU_SOURCE
> #include <string.h>
> #include <stdlib.h>
> #include <stdio.h>
>
> // first correct implementation!
> char * strncpy_good(char *dest, const char *src, size_t count){
> char *tmp = dest;
> memset(dest,'\0',count);
> while (count-- && (*tmp++ = *src++))
> ;
> return dest;
> }

char *strncpy(char * s1, const char * s2, size_t n)
{
register char *s = s1;
while (n) {
if ((*s = *s2) != 0) s2++;
++s;
--n;
}
return s1;
}

-Erik

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Erik B. Andersen http://codepoet-consulting.com/
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