concat_strings.c

#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <stdio.h>
#include "header.h"
#include <dirent.h>
#include "libshell/libshell.h"

#define BUFFER_SIZE 100

/*
 * concat_strings() - Take two strings and concatenate them.
 * @s1: The first string.
 * @s2: The second string.
 *
 * Return: The pointer with the concatentated string.
 */
char *concat_strings(char *s1, char *s2)
{
        int i, j;
	char *p;

	p = malloc( sizeof(char) * ( str_len(s1) + str_len(s2) ) + 1 ); /* allocate memory */

	if (p == NULL) {		/* memory allocation check */
		perror("malloc");
		return "Not enough memory allocated.";
	}

	j = 0;

        for (i = 0; s1[i] != '\0'; ++i) { /* here we copy the first string onto p */
                p[j] = s1[i];
                ++j;
        }

        for (i = 0; s2[i] != '\0'; ++i) { /* here we append the 2nd string onto p */
                p[j] = s2[i];
                ++j;
        }

	p[j] = '\0';		/* append null character at the end */

        return p;
}