-/* Scramble the "inner" letters of each word in the input into a random order, and output the result. Non-word (that is, non-alphabetical) characters, and the first and last letters of each word, are left alone.
- * Output to something other than stdout will append to the file instead of overwriting it - this may be undesirable, and can be changed if so.
- */
-
-/* Copyright 2009-07-11 Andrew J. Buehler.
- */
-
-/* This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <stdio.h>
-#include <ctype.h> // for isalpha()
-#include <stdlib.h> // for malloc()/calloc()/realloc()/free() and rand()/srand()
-#include <string.h> // for strlen()
-#include <time.h> // for time()
-
-#define ALLOW_FILE_IO 1
-
-
-/* strips 'reduction' characters from the end of the input string and returns the result
- * works only if strlen(string> >= reduction, which is the case in the only place it is presently called
- */
-char *shorten_string(char *string, int reduction) {
- int i;
-
- i = strlen(string);
-
- for (; reduction > 0; reduction--, i--) {
- string[i-1] = '\0'; // would it work to use an 'i-reduction' approach instead, similar to what was later done in narrow_string()?
- }
-
- return string;
-}
-
-/* strips 'reduction' characters from the beginning and the end of the input string and returns the result
- * works only if(strlen(string) >= 2*reduction), which is the case in the only place it is presently called
- */
-char *narrow_string(char *string, int reduction) {
- int i = reduction;
-
- while(string[i]) {
- string[i-reduction] = string[i];
- i++;
- }
- string[i-reduction] = '\0';
-
- return shorten_string(string, reduction);
-}
-
-int all_one_letter(char *string) {
- char c;
- int i;
-
- c = string[0];
- for(i = 1; string[i] != '\0'; i++) {
- if(c != string[i]) {
- return 0; // a nonduplicate letter has been found
- }
- c = string[i];
- }
-
- return 1; // reached the end of the string having found only duplicate letters, so it's all one letter
-}
-
-/* randomly reorders the contents of the string
- * WARNING: frees the input string and returns a replacement
- */
-char *scramble_string(char *string) {
- char *ret, *tmpstr;
- int len, i, j;
-
- len = strlen(string);
- if(len < 2) return string; // can't scramble a 1-character string or an empty string!
- if(all_one_letter(string)) return(string); // can't scramble a string which consists entirely of one letter!
-
- ret = strdup(string);
-
- while(strcmp(string, ret) == 0) {
- j = 0;
- tmpstr = strdup(string);
- while(len > 0) {
- i = rand() % len;
- ret[j] = tmpstr[i];
- j++;
- while(tmpstr[i] != '\0') {
- tmpstr[i] = tmpstr[i+1];
- i++;
- }
- len--;
- }
- free(tmpstr);
- len = strlen(string);
- }
-
-
- free(string);
- return ret;
-}
-
-char *clear_string(char *string) {
- int i;
-
- i = strlen(string);
-
- for(; i >= 0 ; i--) {
- string[i] = '\0';
- }
-
- return string;
-}
-
-int main(int argc, char **argv) {
- int word_length;
- char c, tempchar, *word;
- FILE *infile, *outfile;
-
-#if ALLOW_FILE_IO
- /* open files, if any other than stdin and stdout */
- if(argc > 1) {
- if(!strcmp(argv[1], "--help") ||
- !strcmp(argv[1], "-h")) {
- printf("Usage: %s [INPUT_FILENAME] [OUTPUT_FILENAME]\n", argv[0]);
- printf("If INPUT_FILENAME is omitted or is '-', read from standard input\nIf OUTPUT_FILENAME is omitted or is '-', print to standard output\n");
- return 0;
- }
-
- if(strcmp(argv[1], "-")) {
- infile = fopen(argv[1], "r");
- if(infile == NULL) {
- fprintf(stderr, "Unable to open input file %s for reading\n", argv[1]);
- return 1;
- }
- } else {
- infile = stdin;
- }
-
- if(argc > 2) {
- if(strcmp(argv[2], "-")) {
- outfile = fopen(argv[2], "a");
- if(outfile == NULL) {
- fprintf(stderr, "Unable to open output file %s for writing\n", argv[2]);
- return 2;
- }
- } else {
- outfile = stdout;
- }
- }
- } else { // no arguments specified
- infile = stdin;
- outfile = stdout;
- }
-#else
- infile = stdin;
- outfile = stdout;
-#endif
-
- srand(time(NULL)); // needed for scramble_string() to actually be random
-
- word_length = 0;
- word = malloc(sizeof(char));
- word[0] = '\0';
- c = fgetc(infile);
-
- if(feof(infile)) {
- printf("Reached EOF while reading the first character of the input file!\n");
- return 4;
- }
-
- while(!feof(infile)) {
- if(isalpha(c)) {
- word = realloc(word, word_length+2); // one for the new character, one for the null
- word[word_length] = c;
- word[word_length + 1] = '\0'; // duplicate addition with the next line, but possibly more readable
- word_length++;
- } else {
- if(word_length) {
- word_length--;
- fputc(word[0], outfile);
- if(word_length) {
- tempchar = word[word_length];
- word = scramble_string(narrow_string(word, 1));
- fprintf(outfile, "%s", word);
- fputc(tempchar, outfile);
- }
- word = clear_string(word);
- word_length = 0;
- }
- fputc(c, outfile);
- }
- fflush(outfile);
- c = fgetc(infile);
- }
-
- free(word);
- return 0;
-}
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