Implement the strchr function

Implement the strchr function as efficiently as you can..
How do you handle errors if you had to

strchr from pnets libc code

char *
strrchr (const char * s, int c)
{
size_t len = strlen (s);
while (len > 0)
{
--len;
if (s[len] == c)
{
return (char *)(s + len);
}
}
return NULL;
}

Implement the strchr function

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

return *--t ? NULL : t;
}[/code:1]