Valgrind - nicht initialisierte Werte Nachricht

Question

Ich habe einige mysteriöse nicht initialisierte Werte Nachricht von Valgrind erhalten und es war ziemlich das Geheimnis, woher der schlechte Wert stammt. Weiß niemand, wo das Problem ist? Vielen Dank Es gibt memmory Fehler, die ich immer haben:

==26075== Memcheck, a memory error detector 
==26075== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al. 
==26075== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info 
==26075== Command: ./main 
==26075== 
==26075== Conditional jump or move depends on uninitialised value(s) 
==26075== at 0x4C2A020: strcmp (mc_replace_strmem.c:711) 
==26075== by 0x400CF6: stringcmp (main.c:121) 
==26075== by 0x4E64C69: msort_with_tmp (msort.c:84) 
==26075== by 0x4E6503B: qsort_r (msort.c:298) 
==26075== by 0x400930: main (main.c:42) 
==26075== 
==26075== Conditional jump or move depends on uninitialised value(s) 
==26075== at 0x4C2A024: strcmp (mc_replace_strmem.c:711) 
==26075== by 0x400CF6: stringcmp (main.c:121) 
==26075== by 0x4E64C69: msort_with_tmp (msort.c:84) 
==26075== by 0x4E6503B: qsort_r (msort.c:298) 
==26075== by 0x400930: main (main.c:42) 
==26075== 
==26075== 
==26075== HEAP SUMMARY: 
==26075==  in use at exit: 0 bytes in 0 blocks 
==26075== total heap usage: 4 allocs, 4 frees, 31 bytes allocated 
==26075== 
==26075== All heap blocks were freed -- no leaks are possible 
==26075== 
==26075== For counts of detected and suppressed errors, rerun with: -v 
==26075== Use --track-origins=yes to see where uninitialised values come from 
==26075== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 4 from 4) 

Es ist mein Code:

#include <stdio.h> 
#include <string.h> 
#include <malloc.h> 
#include <stdlib.h> 

char *input; 
int row = 0; 


int stringcmp(const void *a, const void *b); 

void permute(int n, int fix, char **arr); 

int factorial(int n); 

void swapSort(char array[], int left, int right); 

void quick_sort(char *array, int left, int right); 

void free2DArray(char **array, int row); 

int main() { 
    input = (char *) malloc(8 + 1 * sizeof(char)); 
    fgets(input, 9, stdin); 
    int n = strlen(input); 
    if (input[n - 1] == '\n') { 
     n--; 
     input[n] = '\0'; 
    } 
    int f = factorial(n); 
    printf("Length of string: %d\n", n); 
    printf("Input string: \"%s\"\n", input); 
    quick_sort(input, 0, n); 
    printf("Sorted: \"%s\"\n", input); 
    printf("Number of permutations: %d\n", f); 
    char **arrOfPermutations = (char **) malloc(factorial(n) * sizeof(char *)); 
    for (int i = 0; i < factorial(n); i++) { 
     arrOfPermutations[i] = (char *) malloc((n + 1) * sizeof(char)); 
    } 

    permute(n, n, arrOfPermutations); 
    qsort(arrOfPermutations, f, sizeof(char *), stringcmp); 
    for (int i = 0; i < f; i++) { 
     printf("\""); 
     for (int j = 0; j < n; j++) { 
      printf("%c", arrOfPermutations[i][j]); 
     } 
     printf("\"\n"); 
    } 
    free2DArray(arrOfPermutations, f); 
    free(input); 

    return 0; 
} 


void free2DArray(char **array, int row) { 
    for (row -= 1; row >= 0; row--) 
     free(array[row]); 
    free(array); 
} 

void permute(int n, int fix, char **arr) { 
    int i, j; 
    char temp; 
    if (n == 0) { 
     for (j = fix - 1, i = 0; j >= 0; j--, i++) { 
      arr[row][i] = input[j]; 
     } 
     row++; 
    } 
    for (i = 0; i < n; i++) { 
     temp = input[i]; 
     for (j = i + 1; j < n; j++) { 
      input[j - 1] = input[j]; 
     } 
     input[n - 1] = temp; 

     permute(n - 1, fix, arr); 

     for (j = n - 1; j > i; j--) { 
      input[j] = input[j - 1]; 
     } 
     input[i] = temp; 
    } 
} 

int factorial(int n) { 
    if (n == 1) return 1; 
    return n * factorial(n - 1); 

} 


void quick_sort(char *array, int left, int right) { 
    if (left < right) { 
     int boundary = left; 
     for (int i = left + 1; i < right; i++) { 
      if (array[i] < array[left]) { 
       swapSort(array, i, ++boundary); 
      } 
     } 
     swapSort(array, left, boundary); 
     quick_sort(array, left, boundary); 
     quick_sort(array, boundary + 1, right); 
    } 

} 

void swapSort(char array[], int left, int right) { 
    char tmp = array[right]; 
    array[right] = array[left]; 

    array[left] = tmp; 
} 


int stringcmp(const void *a, const void *b) { 
    const char **ia = (const char **) a; 
    const char **ib = (const char **) b; 
    return strcmp(*ia, *ib); 
} 

Answer 1

Neben einigen anderen kleineren Probleme Sie sind richtig Reverse-Kopieren einer Zeichenfolge jedoch ohne Anhängen von Null-Byte am Ende.

if (n == 0) { 
    for (j = fix - 1, i = 0; j >= 0; j--, i++) { <<-- The problem is in this line 
     arr[row][i] = input[j]; 
    } 
    row++; 
} 

Sie können nicht Reverse- Kopie end-of-line-Marker, wie es am Ende bleiben sollte, so dass Sie es hinzufügen müssen danach:

if (n == 0) { 
    for (j = fix - 1, i = 0; j >= 0; j--, i++) { 
     arr[row][i] = input[j]; 
    } 
    arr[row][fix]=0; <<-- the fix 
    row++; 
}