49 lines
1.4 KiB
C
49 lines
1.4 KiB
C
/* Copyright (C) 2016 Jeremiah Orians
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* This file is part of M2-Planet.
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*
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* M2-Planet is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* M2-Planet is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with M2-Planet. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include<stdlib.h>
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#include<string.h>
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#include<stdio.h>
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// void* calloc(int count, int size);
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int hex2char(int c);
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void require(int bool, char* error);
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char* number_to_hex(int a, int bytes)
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{
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require(bytes > 0, "number to hex must have a positive number of bytes greater than zero\n");
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char* result = calloc(1 + (bytes << 1), sizeof(char));
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if(NULL == result)
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{
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fputs("calloc failed in number_to_hex\n", stderr);
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exit(EXIT_FAILURE);
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}
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int i = 0;
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int divisor = (bytes << 3);
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require(divisor > 0, "unexpected wrap around in number_to_hex\n");
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/* Simply collect numbers until divisor is gone */
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while(0 != divisor)
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{
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divisor = divisor - 4;
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result[i] = hex2char((a >> divisor) & 0xF);
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i = i + 1;
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}
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return result;
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}
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