33 lines
786 B
C
33 lines
786 B
C
#include <stdio.h>
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int main(int argc, char **argv) {
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if (argc < 2) {
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fprintf(stderr, "Usage: xor [FILE]...\nAll files XORed to stdout, size: minimum of all.\n");
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return(1);
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}
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int nbFiles = argc-1;
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FILE *files[nbFiles];
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bool errors = false;
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for (int i=0;i<nbFiles;i++) {
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files[i] = fopen(argv[i+1], "r");
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if (files[i] == NULL) {
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fprintf(stderr, "Could not open '%s'.\n", argv[i+1]);
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errors = true;
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}
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}
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if (errors) return(1);
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char c[argc-1];
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do {
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int cc;
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for (int i=0;i<nbFiles;i++) {
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cc = fgetc(files[i]);
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if (cc == EOF) break;
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c[i] = (char)cc;
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}
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if (cc == EOF) break;
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char xored = '\0';
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for (int i=0;i<nbFiles;i++) xored ^= c[i];
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printf("%c", xored);
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} while(1);
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}
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