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/**
* @author Michael Duell <michael.duell@rub.de>
*
* Released under the MIT license.
*
* Copyright (c) 2017 Michael Duell <michael.duell@rub.de>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
**/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define ALPHABET_SIZE 26
#define LOWER_CASE_BIT 32
#define ROTATION 13
#define OFFSET 'a'
int islower_ascii(unsigned cnum) {
return cnum >= OFFSET;
}
char transpose(char c){
unsigned cnum = (unsigned)c;
unsigned offset = (unsigned)OFFSET;
if ((cnum | LOWER_CASE_BIT) - OFFSET < ALPHABET_SIZE) {
if (!islower_ascii(cnum)) {
offset -= LOWER_CASE_BIT;
}
cnum -= offset;
cnum += ROTATION;
cnum %= ALPHABET_SIZE;
cnum += offset;
}
return (char)cnum;
}
int main(int argc, char **argv)
{
char c;
if (argc > 1) {
for (int i = 1; i < argc; i++) {
for (int j = 0; j < strlen(argv[i]); j++) {
putchar(transpose(argv[i][j]));
}
putchar(' ');
}
putchar('\n');
} else {
while ((c = getchar()) != EOF) {
putchar(transpose(c));
}
}
return EXIT_SUCCESS;
}
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