// lang.c
// Author: Josh Holtrop
// Date: 12/30/04
// Modified: 12/30/04

#include "lang.h"


/* strcmp compares two strings
 * Returns:
 *  0 if the strings are equal
 * <0 if the second string is less than the first
 * >0 if the second string is greater than the first
 */
int	strcmp(char *str1, char *str2)
{
	while (*str1 || *str2)
	{
		if (*str1 != *str2)
			return *str2 - *str1;
		str1++;
		str2++;
	}
	return 0;
}

/* strncmp compares up to n characters of two strings
 * Returns:
 *  0 if the strings are equal
 * <0 if the second string is less than the first
 * >0 if the second string is greater than the first
 */
int	strncmp(char *str1, char *str2, int n)
{
	while (n > 0 && (*str1 || *str2))
	{
		if (*str1 != *str2)
			return *str2 - *str1;
		str1++;
		str2++;
		n--;
	}
	return 0;
}


/* str_change changes a certain character in a string
 *  to a different character
 * Returns: how many characters were changed
 */
int str_change(char *str, char ch1, char ch2)
{
  int count = 0;
  while (*str)
    {
      if (*str == ch1)
	{
	  *str = ch2;
	  count++;
	}
      str++;
    }
  return count;
}

// counts the occurrences of lookfor in str
int	str_count(char *str, char lookfor)
{
	int count = 0;
	while (*str)
	{
		if (*str == lookfor)
			count++;
		str++;
	}
	return count;
}

// split the string into substrings by the splitchar, return number of substrings
int	str_split(char *str, char splitchar)
{
  if (!(*str))
    return 0;
	int subs = 1;
	while (*str)
	{
		if (*str == splitchar)
		{
			*str = 0;
			subs++;
		}
		str++;
	}
	return subs;
}

// advance the string pointer to the next substring, return a pointer to the next substring
char	*str_advance(char *str)
{
	char *next = str;
	while (*next)
		next++;			// advance pointer to end of this substring (null character)
	return next + 1;
}


// concatentate src onto the end of dest
void	strcat(char *dest, char *src)
{
	while (*dest)
		dest++;
	strcpy(dest, src);
}