util2.c

#include "main.h"

/**
 * _atoi - converts string to an integer
 * @s: Pointer to character string
 *
 * Return: returns integer value
 */
int _atoi(char *s)
{
	int sign;
	unsigned int num;
	char *temp;

	temp = s;
	num = 0;
	sign = 1;
	while (*temp != '\0' && (*temp < '0' || *temp > '9'))
	{
		if (*temp == '-')
			sign *= -1;
		temp++;
	}
	if (*temp != '\0')
	{
		do {
			num = num * 10 + (*temp - '0');
			temp++;
		} while (*temp >= '0' && *temp <= '9');
	}
	return (num * sign);
}

/**
 * _strstr - finds the first occurrence of the substring.
 * needle in the string haystack.
 * @haystack: entire string.
 * @needle: substring.
 * Return: pointer to the beginning of located substring or
 * NULL if the substring is not found.
*/
char *_strstr(char *haystack, char *needle)
{
	char *bhaystack;
	char *pneedle;

	while (*haystack != '\0')
	{
		bhaystack = haystack;
		pneedle = needle;

		while (*haystack != '\0' && *pneedle != '\0' && *haystack == *pneedle)
		{
			haystack++;
			pneedle++;
		}
		if (!*pneedle)
			return (bhaystack);
		haystack = bhaystack + 1;
	}
	return (0);
}

/**
 *_strcat - Write a function that concatenates two strings.
 *
 *@dest: This is the output dest
 *@src: This is the input source
 *
 * Return: This return to dest, that concatenates two strings
 */

char *_strcat(char *dest, char *src)
{
	int i, j, k;

	i = 0, j = 0;
	while (dest[i] != '\0')
		i++;
	while (src[j] != '\0')
		j++;
	for (k = 0; k <= j; k++, i++)
		dest[i] = src[k];
	return (dest);
}