str_fun.c

int len(char *s)
{
	int l = 0;
	while (*s != '\0')
	{
		l++;
		s++;
	}
	return (l);
}
int coun_vow(char *s)
{
	int c = 0;
	while (*s != '\0')
	{
		switch (*s)
		{
		case 'a':
		case 'e':
		case 'o':
		case 'i':
		case 'u':
		case 'A':
		case 'E':
		case 'U':
		case 'I':
		case 'O':
			c++;
			break;
		}
		s++;
	}
	return c;
}
void copy(char *s, char *t)
{
	while (*s != '\0')
	{
		*t = *s;
		t++;
		s++;
	}
	*t = '\0';
}

void add(char *t, char *s)
{
	while (*t != '\0')
		t++;
	while (*s != '\0')
	{
		*t = *s;
		s++;
		t++;
	}
	*t = '\0';
}
int comp(char *t, char *s)
{
	int c;
	while (*t != '\0')
	{
		c = *s - *t;
		s++;
		t++;
	}
	return c;
}
char *rev(char *s)
{
	char t;
	int i, l;
	l = len(s);
	for (i = 0; i < l / 2; i++)
	{
		t = *(s + i);
		*(s + i) = *(s + l - 1 - i);
		*(s + l - 1 - i) = t;
	}
	return (s);
}