80 lines
2.1 KiB
C
80 lines
2.1 KiB
C
#include "a3.h"
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#include <stdio.h>
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#include <memory.h>
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#include <malloc.h>
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#include <stdint.h>
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void memdump(unsigned char *string) {
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printf("ADDR\t\t00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 0123456789ABCDEF\n");
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int columns = 16;
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int rows = 4;
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char symbols[columns * rows];
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if((long) string % 16 != 0) {
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string = string - ((long) string % 16);
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}
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for(int i = 0; i < rows; i++) {
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printf("%p\t", (void *) &string[i * columns]);//print address
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if((long) string % 16 != 0) {
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printf("oh nein, kein mod 16");
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}
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for (int j = i * columns; j < (i + 1) * columns; j++) {
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printf("%02x ", string[j]);//print char number
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if(string[j] < 0x20 || string[j] > 0x7e)//check for printable characters
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symbols[j] = '.';
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else symbols[j] = string[j];
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}
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printf(" ");
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//print characters
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for (int j = i * columns; j < (i + 1) * columns; j++) {
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printf("%c", symbols[j]);
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}
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printf("\n");
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}
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}
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int memreplace(char *string, char cin, char cout, char **caddr) {
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int found = 0;
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for (int i = 0; i < strlen(string); ++i) {
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//if char is to be replaced
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if(string[i] == cin) {
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string[i] = cout;//replace char
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found++;
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*caddr = &string[i];//setting last found address
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}
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}
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return found;
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}
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int main(int argc, char **argv) {
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if(argc != 4) {
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printf("Not enough arguments or to many arguments");
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return -1;
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}
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memdump((unsigned char *) argv[0]);
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printf("\tLaenge der Zeichenkette (inkl \\0): %i Byte(s)\n", (int) strlen(argv[1]));
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printf("\tErsetzen: '%c' mit '%c'\n", *argv[2], *argv[3]);
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unsigned char *copy = malloc(4 * 16 * sizeof(char));//allocate memory for all chars
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strcpy((char *) copy, argv[1]);
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char *lastAddress = NULL;
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int count = memreplace((char *) copy, *argv[2], *argv[3], &lastAddress);
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printf("\tSuchzeichen wurde %i mal gefunden und ersetzt\n", count);
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printf("\tzuletzt an Addresse %p \n", (void *) lastAddress);
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memdump(copy);
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free(copy);
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return 0;
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} |