Function remove space in C

char *replcace(char str[]) {
char *p1 = str;
char *p2 = str;
p1 = str;
while (*p1 != 0) {
if (ispunct(*p1) || isspace(*p1)) {
++p1;
} else
*p2++ = *p1++;
}
*p2 = 0;
return str;
}