str_1.c

#include "shell.h"

size_t strlen_alt(const char *s);
char *strcat_alt(char *dest, const char *src);
int strcmp_alt(char *s1, char *s2);
char *strchr_alt(const char *s, char c);
char *strcpy_alt(char *destination, char *source);
char *getenv_alt(const char *variable_name);
/**
 *strlen_alt - Entry point
 * Description - 'function returning length of a string'
 * @s: string to be measured
 *
 * Return: the length of given string 's'
 */
size_t strlen_alt(const char *s)
{
	size_t len = 0;

	while (s[len] != '\0')
	{
		len++;
	}
	return (len);
}

/**
 * strcat_alt - Entry point
 * Description - 'a function concantenating two strings'
 * @dest: char string type
 * @src: char string type
 *
 * Return: pointer to the concantenated string
 */
char *strcat_alt(char *dest, const char *src)
{
	int dest_len = 0;
	int h;


	/*Find the length of the destination string*/


	while (dest[dest_len] != '\0')
	{
		dest_len++;
	}


	/*append the first string to the destination string */


	for (h = 0; src[h] != '\0'; h++)
	{
		dest[dest_len + h] = src[h];
	}
	/* add null terminating character to concantenated string */


	dest[dest_len + h] = '\0';


	return (dest);
}




/**
 * strcmp_alt - Entry point
 * Description - 'a function comparing two strings'
 * @s1: first string to be checked
 * @s2: second string to be checked
 *
 * Return: value less than 0 means s1 is less than s2
 * value equal to 0 meants s1 = s2
 * value greater than 0 means s1 is greater than s2
 */


int strcmp_alt(char *s1, char *s2)
{
	int len;


	for (len = 0; s1[len] == s2[len] && s1[len]; len++)
		;


	if (s1[len] > s2[len])
		return (1);
	if (s1[len] < s2[len])
		return (-1);
	return (0);
}




/**
 * strchr_alt - Entry point
 * Description - ' a function searching for the first occurence of a character
 * in a string'
 * @s: a pointer to the string to be searched
 * @c: the character to be searched for
 *
 * Return: a pointer to the first occurrence of the char c in s
 * 0R 0 if char c is not found in s
 */


char *strchr_alt(const char *s, char c)
{
	while (*s != '\0')
	{
		if (*s == c)
			return ((char *)s);
		s++;
	}
	return (NULL);
}

/**
 * memcpy_alt - Entry point
 * Description: 'function copying memory area'
 * @src: source char string type
 * @dest: destination string type
 * @n: maximum number of byte area to be copied
 * Return: pointer to destination string
 */


char *memcpy_alt(char *dest, char *src, unsigned int n)
{
	unsigned int h = 0;


	for (h = 0; h < n; h++)
	{
		dest[h] = src[h];


	}
	return (dest);
}
/**
 * strcpy_alt - Entry point
 * Description - 'a function copying one pointer to another pointer'
 * @source: char type string
 * @destination: char string type
 * Return: Pointer to dest
 */

char *strcpy_alt(char *destination, char *source)
{
	int h = 0;

	while (source[h] != '\0')
	{
		destination[h] = source[h];
		h++;
	}
	destination[h] = '\0';
	return (destination);
}

/**
 * getenv_alt - Retrieves the value of an environment variable
 * @variable_name: The name of the variable to retrieve
 *
 * Return: The value of the environment variable, or NULL if not found
 */
char *getenv_alt(const char *variable_name)
{
	int name_length = strlen_alt(variable_name);

	char **env;

	for (env = environ; *env; ++env)
	{
		if (strncmp_alt(variable_name, *env, name_length)
				== 0 && (*env)[name_length] == '=')
		{
			return (&((*env)[name_length + 1]));
		}
	}
	return (NULL);
}