strlib.c

来自「ADS下的bios工程」· C语言 代码 · 共 104 行

#include <bios/stdio.h>
#include <bios/string.h>

u32 str_ncmp(char* str1 , char* str2 , u32 n)
{
        u32 i = 0;

        while(i < n) {
                if(str1[i] != str2[i]) return  1;
                i++;
        }
        return  0;
}

u32 strtoint(char *str, u32 count)
{
        u32 temp = 0;
        u32 total = 0 ;

        while(count)
        {
                temp = *str++ - '0';
                total += temp * power(10,count-1);
                count--;
        }
        return total;
}

u32 hexstrtohex(char *str, u32 count)
{
        u32 temp = 0;
        u32 total = 0 ;

        while(count)
        {
                count--;
                if(('0'<=(*str))&&((*str) <= '9'))
                {
                        temp = *str - '0';
                    total += temp << (4*count);
                    temp = 0;
                }
                else if(('a'<=(*str))&&((*str) <= 'f'))
                {
                        switch(*str)
                        {
                                case 'a': temp = 10; break;
                                case 'b': temp = 11; break;
                                case 'c': temp = 12; break;
                                case 'd': temp = 13; break;
                                case 'e': temp = 14; break;
                                case 'f': temp = 15; break;
                                default: break;
                        }
                        total +=temp << (4*count);
                        temp = 0;
                }
                str++;
        }
        return total;
}

u32 strlen(char *s)
{
        return strnlen(s, MAX_LINE_SIZE);
}

int power(u32 value, u32 n)
{
        int       count;
        u32       result = 1; /* value returned */
         
        if (n < 0)
             return -1;

        for(count = 0; count < n; count++)
               result =  result * value; 

        return result;
}

char * strcat(char * dest, char * src)
{
	char *tmp = dest;

	while (*dest)
		dest++;
	while ((*dest++ = *src++) != '\0') ;

	return tmp;
}

char * strchr(char *s, int c)
{
     register char ch;

     for(;;)
     {
	 if((ch= *s) == c) return s;
	 if(ch == '\0') return 0;
	 s++;
     }
}