Trying to sort for the nth word in an array

Question

I am working on a code that takes parameters:

• -d (which sorts text descending)
• -L (which sorts lines per length)
• -L and -d (which does both)
• -n (which sorts the text to the nth word)

I'm trying to read a file and sort its output like in the parameters above described. If no file is given as a parameter the program switches to user input and sorts that input.

But I'm only getting a segmentation fault :( and I don't know where. I think the segmentation fault happens somewhere in the Bubblesort. Maybe I'm using the strchrnul function wrong?

#define _GNU_SOURCE 
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#define MAX_ZEILEN 1000
#define ZEILEN_LEN 500


// Array ausgeben
void printArray(char *arr[], int n)
{
    for (int i = 0; i < n; ++i)
        printf("%s\n", arr[i]);
}

// Vertauscht das j Element mit dem j+1
void swap(char **arr, int j)
{
    char *tmp = arr[j];
    arr[j] = arr[j+1];
    arr[j+1] = tmp;
}

char * ab_wort(char*str,int n)
{
    while(n>0){
        str = strchrnul(str,' ');
        if(*str == ' ') ++str;
    }
    return str;
}

// Bubble sort
void bubbleSort(char *arr[], int n, char *option_d, char *option_L, char *option_n)
{
    int i, j, option = 0;

    if(strcmp(option_L, "-L") && strcmp(option_d, "-d"))
        option = 2;
    else if(strcmp(option_d, "-d"))
        option = 0;
    else if(strcmp(option_L, "-L"))
        option = 1;
    if(strcmp(option_n, "-n"))
        option = 3;

    for (i = 0; i < n-1; ++i)
    {
        for (j = 0; j < n-i-1; ++j)
        {
            switch(option)
            {
                case 0:     //-d
                    if (strcmp(arr[j], arr[j+1]) > 0)
                        swap(arr, j); //swap(arr[j], arr[j+1]); // <-- Wär das möglich?
                    else if (strcmp(arr[j], arr[j+1]) < 0)
                        swap(arr, j);
                    break;
                case 1:     //-L

                    if (strlen(arr[j]) > strlen(arr[j+1]))
                            swap(arr, j); //swap(arr[j], arr[j+1]); // <-- Wär das möglich?
                    else if (strlen(arr[j]) < strlen(arr[j+1]))
                            swap(arr, j);
                    break;
                case 2: // -d und -L werden angegeben 

                    if (strcmp(arr[j], arr[j+1]) > 0)  /// von -d option
                            swap(arr, j);
                    else if (strcmp(arr[j], arr[j+1]) < 0)
                            swap(arr, j);
                    if (strlen(arr[j]) > strlen(arr[j+1])) // von -L option
                            swap(arr, j); 
                    else if (strlen(arr[j]) < strlen(arr[j+1]))
                            swap(arr, j);
                    break;
                case 3:     // sortieren nach dem n-ten wort

                    if (strcmp(ab_wort(arr[j],2),ab_wort(arr[j+1],2)))
                        swap(arr,j);
                    break;
                


                default:
                    break;
            }
        }
    }
}



/* Bubble sort
void lengthSort(char *arr[], int n, char *option_L)
{
    int i, j, option = 0;
    if(strcmp(option_L, "-L"))
        option++;

    for (i = 0; i < n-1; ++i)
    {
        for (j = 0; j < n-i-1; ++j)
        {
            switch(option)
            {
                case 0:
                    if (strlen(arr[j]) > strlen(arr[j+1]))
                        swap(arr, j); //swap(arr[j], arr[j+1]); // <-- Wär das möglich?
                    break;
                case 1:
                    if (strlen(arr[j]) < strlen(arr[j+1]))
                        swap(arr, j);
                    break;
                default:
                    break;
            }
        }
    }
}*/


void userInputEinlesen(char **pv, int *len)
{
    char str[ZEILEN_LEN];

    for (int i = 0; i < MAX_ZEILEN; ++i)
    {
        if (fgets(str, ZEILEN_LEN, stdin) == NULL)
            break;

        str[strcspn(str, "\r\n")] = 0;

        if (strcmp(str, "") == 0)
                continue;

        pv[i] = strcpy((char *) malloc(sizeof(char) * strlen(str) + 1), str);
        ++(*len);
    }
}

int filesEinlesen(char **pv, char *filename, int *len, int argc)
{
    char str[ZEILEN_LEN];
    FILE *fp;


    for (int j = 0;  j < 1 ;)
    {
        fp = fopen(filename, "r");
        if(fp == NULL)
        {
            fprintf(stderr, "Error opening file %s\n", filename);
            return -1;
        }

        while(fgets(str, ZEILEN_LEN, fp) && j < MAX_ZEILEN)
        {
            str[strcspn(str, "\r\n")] = 0;

            if (strcmp(str, "") == 0)
                continue;

            pv[j] = strcpy((char *) malloc(sizeof(char) * strlen(str) + 1), str);
            //printf("S: %s\n", pv[j]);
            ++j;
            ++(*len);
        }

        fclose(fp);
    }

    return 0;
}

void freeStorage(char *arr[], int n)
{
    for (int i = 0; i < n; ++i)
        free(arr[i]);
}

int main(int argc, char *argv[])
{
    char *pv[MAX_ZEILEN];
    int len = 0;
    char option_L;
    char option_d;
    char option_n;

    for (int i = 0; i < argc; i++)
    {
        if (argc > 1 && !strcmp(argv[i], "-d"))
        {
            option_d = *argv[i];
            printf("option d wurde erkannt ! \n");
        }
        if (argc > 1 && !strcmp(argv[i], "-L"))
        {
            option_L = *argv[i];
            printf("option L wurde erkannt ! \n");
        }
        if (argc > 1 && !strcmp(argv[i], "-n"))
        {
            option_n = *argv[i];
            printf("option n wurde erkannt ! \n");
        }
    
    }
    
    
    //if (argc > 1 && !strcmp(argv[1], "-L"))

    //    ++opt_d;

    
    // Dateien einlesen wenn angegeben, sonst User Input

    char *filename;
    int acc;

    for ( int i = 1; i < argc; i++)
    {
        if( access( argv[i], F_OK ) == 0 )
        {
            printf("AccessGranted\n");
            acc = 1;
            filename = argv[i];
            break;
        }
    }


        printf("ARGC = %d \n", argc);
        if( acc == 1)
        {
             
            printf("Filename wurder erkannt! :     %s\n", filename);
            filesEinlesen(pv, filename, &len, argc);
            
        }
        else
        {
            userInputEinlesen(pv, &len);
            printf("---------\n");
        }


    printf("Zeilen: %d\n", len);

    //printArray(pv, len);
    bubbleSort(pv, len, &option_d, &option_L, &option_n);
    printArray(pv, len);

    // Speicher wieder freigeben
    freeStorage(pv, len);

    return 0;
}