C: validity of pointers

Question

I've written this code to read values from a file, and if a read value is a ";" is, all values that occurred up to now and were written in a string should be written into a field of a pointer array

    #include <stdio.h>
    #include <stdlib.h>
    #include <stdbool.h>
    #include <windows.h>
    #define SIZE_STRINGS 100
    #define SIZE_ZS 15

    int index_drei;
    char *laenge_drei[SIZE_STRINGS];

    char* string_to_pointer(char []);
    void laengen_block_nach_siegen_ordnen();

    void spielweg_nach_laenge_des_spieweges_ordnen(bool spieler)
    {
        int i,
            laenge,
            index_zs;
        char buchstabe,
             zs[SIZE_ZS],
             zs2[SIZE_ZS],
             *zs_p;
        bool akt_laenge_auslesen;
        FILE * fp;

        if(spieler)
            fp = fopen("Anlagen\\spielweg_spieler.txt", "r"); //Datei öffnen
        else
            fp = fopen("Anlagen\\spielweg_ai.txt", "r"); //Datei öffnen

        akt_laenge_auslesen = true;
        index_drei = 0;

        laenge = 0;
        index_zs = 0;
        for(i = 0; i < SIZE_ZS; i++)
        {
            zs[i] = 0;
        }

        if(fp == NULL)
        {
        }else
        {
            while((buchstabe = fgetc(fp))!=EOF)
            {
                zs[index_zs] = buchstabe;
                index_zs++;
                if(akt_laenge_auslesen == true && buchstabe == '-')
                    akt_laenge_auslesen = false;
                else if(akt_laenge_auslesen)
                    laenge = buchstabe - '0';
                else if(buchstabe == ';')
                {
                    if(laenge == 3)
                    {
                        laenge_drei[index_drei] = string_to_pointer(zs);
                        /*Firts value*/
                        strcpy(zs2, laenge_drei[0]);
                        printf("%s", zs2);Sleep(1000);
                        index_drei++;
                    }
                    akt_laenge_auslesen = true;
                    laenge = 0;
                    index_zs = 0;
                    for(i = 0; i < SIZE_ZS; i++)
                    {
                        zs[i] = 0;
                    }
                }
            }
            /*Second value*/
            strcpy(zs2, laenge_drei[0]);
            printf("%s", zs2);Sleep(1000);
            fclose(fp);
        }
    }

    char* string_to_pointer(char string[])
    {
        return string;
    }

If I write the value from "length_drei [0]" with strcpy in string "zs2", I get:

• / * First value * / the right value
• / * Second value * / the wrong value (one space)

Answer 1

You aren't allocating any memory for the string segments you're trying to save in laenge_drei. At the end of the loop, each index of laenge_drei contains a reference to zs and therefore the last string processed.

if(laenge == 3)
{
    laenge_drei[index_drei] = strdup(zs);
    printf("%s", laenge_drei[index_drei]);
    sleep(1000);
    index_drei++;
}

Change strcpy(zs2, laenge_drei[0]) to strcpy(zs2, laenge_drei[index_drei]) if you're trying to print out each segment or you'll just keep printing the first one over and over again.

When you exit the loop & try to print laenge_drei[0] again, it will still have the first value. Don't forget to free your memory.