90 lines
2.0 KiB
C
90 lines
2.0 KiB
C
include <stdio.h>
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#include <stdlib.h>
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void deplacerPremierOctet(const char *filename) {
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FILE *file;
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unsigned char first_byte;
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long file_size;
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unsigned char *buffer;
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file = fopen(filename, "r+b");
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if (file == NULL) {
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perror("Erreur d'ouverture");
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exit(EXIT_FAILURE);
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}
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if (fread(&first_byte, 1, 1, file) != 1) {
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perror("Erreur de lecture");
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fclose(file);
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exit(EXIT_FAILURE);
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}
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fseek(file, 0, SEEK_END);
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if (fwrite(&first_byte, 1, 1, file) != 1) {
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perror("Erreur d'écriture");
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fclose(file);
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exit(EXIT_FAILURE);
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}
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file_size = ftell(file);
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fclose(file);
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file = fopen(filename, "r+b");
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if (file == NULL) {
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perror("Erreur d'ouverture");
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exit(EXIT_FAILURE);
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}
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buffer = (unsigned char *)malloc(file_size - 1);
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if (buffer == NULL) {
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perror("Erreur d'allocation mémoire");
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fclose(file);
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exit(EXIT_FAILURE);
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}
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fseek(file, 1, SEEK_SET);
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if (fread(buffer, 1, file_size - 1, file) != file_size - 1) {
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perror("Erreur de lecture");
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free(buffer);
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fclose(file);
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exit(EXIT_FAILURE);
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}
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fclose(file);
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file = fopen(filename, "wb");
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if (file == NULL) {
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perror("Erreur d'ouverture");
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free(buffer);
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exit(EXIT_FAILURE);
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}
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if (fwrite(buffer, 1, file_size - 1, file) != file_size - 1) {
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perror("Erreur d'écriture");
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free(buffer);
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fclose(file);
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exit(EXIT_FAILURE);
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}
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if (fwrite(&first_byte, 1, 1, file) != 1) {
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perror("Erreur d'écriture");
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free(buffer);
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fclose(file);
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exit(EXIT_FAILURE);
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}
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free(buffer);
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fclose(file);
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printf("Modification effectuée.\n");
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}
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int main(int argc, char *argv[]) {
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if (argc != 2) {
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fprintf(stderr, "Usage: %s <toto.c>\n", argv[0]);
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exit(EXIT_FAILURE);
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}
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deplacerPremierOctet(argv[1]);
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return 0;
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} |