128 lines
2.7 KiB
C
Executable File
128 lines
2.7 KiB
C
Executable File
#define _POSIX_C_SOURCE 200809L
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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int main(int argc, char ** argv) {
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int silent_mode = 0;
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int print_all_diff = 0;
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int keep_printing = 1;
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int files_differ = 0;
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int i, f1num = 1;
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FILE *file1, *file2;
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char c1, c2, c;
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int line = 1, byte = 1;
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while((c = getopt(argc, argv, "sl")) != -1) {
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switch(c) {
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case 's': silent_mode = 1; print_all_diff = 0; break;
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case 'l': print_all_diff = 1; silent_mode = 0; break;
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}
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}
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f1num = optind;
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if(argc - f1num < 2) {
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fprintf(stderr, "%s: missing file operand\n", argv[0]);
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return 3;
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}
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if(strcmp(argv[f1num], "-") == 0 && strcmp(argv[f1num+1], "-") == 0) {
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fprintf(stderr, "%s: cannot accept stdin for both files\n", argv[0]);
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return 2;
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}
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else if(strcmp(argv[f1num], "-") == 0) {
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file1 = stdin;
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file2 = fopen(argv[f1num+1], "r");
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}
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else if(strcmp(argv[f1num+1], "-") == 0) {
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file1 = fopen(argv[f1num], "r");
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file2 = stdin;
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}
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else {
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file1 = fopen(argv[f1num], "r");
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file2 = fopen(argv[f1num+1], "r");
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}
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if(file1 == NULL) {
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fprintf(stderr, "%s: could not open file %s\n", argv[0], argv[f1num]);
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return 4;
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}
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if(file2 == NULL) {
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fprintf(stderr, "%s: could not open file %s\n", argv[0], argv[f1num + 1]);
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return 4;
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}
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if(silent_mode) {
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c1 = fgetc(file1);
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c2 = fgetc(file2);
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for(i = 0; !(c1 == EOF || c2 == EOF); i++) {
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if(c1 != c2) {
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return 1;
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}
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c1 = fgetc(file1);
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c2 = fgetc(file2);
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}
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if(c1 != c2) {
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return 1;
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}
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else {
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return 0;
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}
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}
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else if(print_all_diff) {
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c1 = fgetc(file1);
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c2 = fgetc(file2);
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for(i = 0; !(c1 == EOF || c2 == EOF); i++) {
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if(c1 != c2) {
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printf("%d %o %o\n", byte, c1, c2);
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files_differ = 1;
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}
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c1 = fgetc(file1);
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c2 = fgetc(file2);
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line++;
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byte++;
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}
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if(c1 != c2) {
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fprintf(stderr, "%s: EOF on %s%s\n", argv[0],
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c1 == EOF ? argv[f1num] : argv[f1num+1], "");
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return 1;
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}
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else if(files_differ) {
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return 1;
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}
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else {
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return 0;
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}
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}
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else {
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c1 = fgetc(file1);
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c2 = fgetc(file2);
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for(i = 0; !(c1 == EOF || c2 == EOF); i++) {
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if(c1 != c2 && keep_printing) {
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keep_printing = 0;
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printf("%s %s differ: char %d, line %d\n", argv[f1num], argv[f1num+1], byte, line);
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files_differ = 1;
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}
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c1 = fgetc(file1);
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c2 = fgetc(file2);
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if(c1 == '\n') line++;
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byte++;
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}
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if(c1 != c2) {
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fprintf(stderr, "%s: EOF on %s%s\n", argv[0],
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c1 == EOF ? argv[f1num] : argv[f1num+1], "");
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return 1;
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}
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else if(files_differ) {
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return 1;
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}
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else {
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return 0;
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}
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}
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}
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