char_to_int.c

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#include "config.h"
#include "char_to_int.h"

#include <stdio.h>

#include "len.h"

short int check_int(const char *s, int len, uint8_t base)
{
        if(s == NULL) return 0;
        char digits[] = "0123456789aAbBcCdDeEfF";
        if(base == 16) base += 6;
        int i;
        for(i = 0; i < len; i++)
        {
                if(_len(digits, s[i]) <= base)
                        continue;
                else
                        return 0;
        }
        return 1;
}

unsigned long long char_to_int(const char *s, int i, uint8_t base)
{
        if(s == NULL)
                return -1;
        if(i == 0)
                i = str_len(s);
        if(i == 0)
                return -1;

        unsigned long long n = 0;
        unsigned long long b = 1;

        for(i -= 1; i >= 0; i--)
        {
                switch(s[i])
                {
                        case '0': break;
                        case '1': n += b; break;
                        case '2': n += 2 * b; break;
                        case '3': n += 3 * b; break;
                        case '4': n += 4 * b; break;
                        case '5': n += 5 * b; break;
                        case '6': n += 6 * b; break;
                        case '7': n += 7 * b; break;
                        case '8': n += 8 * b; break;
                        case '9': n += 9 * b; break;
                        case 'a':
                        case 'A': n += 10 * b; break;
                        case 'b':
                        case 'B': n += 11 * b; break;
                        case 'c':
                        case 'C': n += 12 * b; break;
                        case 'd':
                        case 'D': n += 13 * b; break;
                        case 'e':
                        case 'E': n += 14 * b; break;
                        case 'f':
                        case 'F': n += 15 * b; break;
                        default: break;
                }
                b *= base;
        }
        return n;
}