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Implement the strtok function

Fri, 08/25/2006 - 03:10 — Pooja

What is the fastest possible algorithm with constant space?

‹ Implement the strchr function Implement the strstr function ›
Mon, 03/19/2007 - 01:49 — Pooja

code for strtok from pnetc's libc library

char *
strtok_r (char *s, const char *delim, char **ptrptr)
{
size_t len;
if (!s)
{
s = *ptrptr;
}
len = strspn (s, delim);
s += len;
if (*s == '\0')
{
return 0;
}
*ptrptr = strpbrk (s, delim);
if (!(*ptrptr))
{
*ptrptr = strchr (s, '\0');
}
else
{
*((*ptrptr)++) = '\0';
}
return s;
}

char *
strtok (char *s, const char *delim)
{
static char *ptrptr;
return strtok_r (s, delim, &ptrptr);
}

Mon, 09/11/2006 - 05:59 — geekgod

Implement the strtok function

[code:1]char* str_chr(char* str, char c)
{
char* t = str;
while(*t != c && *t)
t++;

return *--t ? NULL : t;
}
char *str_tok(char *str, char *delims)
{
static char *pos = NULL;
char *start = NULL;

if (str) /* Start a new string? */
pos = str;

if (pos)
{
/* Skip delimiters */
while (*pos && strchr(delims, *pos))
pos++;

if (*pos) {
start = pos;
/* Skip non-delimiters */
while (*pos && !strchr(delims, *pos))
pos++;

if (*pos)
*pos++ = '\0';
}

}

return start;
}[/code:1]