toaruos/boot/util.c

/**
 * @brief Utility functions.
 *
 * Kind of a barebones libc.
 *
 * @copyright
 * This file is part of ToaruOS and is released under the terms
 * of the NCSA / University of Illinois License - see LICENSE.md
 * Copyright (C) 2018-2021 K. Lange
 */
#include "util.h"

int strcmp(const char * l, const char * r) {
	for (; *l == *r && *l; l++, r++);
	return *(unsigned char *)l - *(unsigned char *)r;
}

char * strchr(const char * s, int c) {
	while (*s) {
		if (*s == c) {
			return (char *)s;
		}
		s++;
	}
	return 0;
}

unsigned long strlen(const char *s) {
	unsigned long out = 0;
	while (*s) {
		out++;
		s++;
	}
	return out;
}

char * strcat(char *dest, const char *src) {
	char * end = dest;
	while (*end != '\0') {
		++end;
	}
	while (*src) {
		*end = *src;
		end++;
		src++;
	}
	*end = '\0';
	return dest;
}