dynamic_array_char.c

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

typedef struct {
    char **data;
    size_t used;
    size_t size;
} Array;

void initArray(Array *array, size_t initialSize);

void insertElement(Array *array, char *element);

void freeArray(Array *array);


void initArray(Array *array, size_t initialSize) {
    array->data = malloc(initialSize * sizeof(char *));
    if (array->data == NULL) {
        printf("ERROR: Memory allocation failure!\n");
        exit(1);
    }
    array->used = 0;
    array->size = initialSize;
}

void insertElement(Array *array, char *element) {
    if (array->used == array->size) {
        void *pointer;

        array->size *= 2;
        pointer = realloc(array->data, array->size * sizeof(char *));
        if (array->data == NULL) {
            freeArray(array);
            printf("ERROR: Memory allocation failure!\n");
            exit(1);
        }
        array->data = pointer;
    }
    /* if the string passed is not NULL, copy it */
    if (element != NULL) {
        size_t length;

        length = strlen(element);
        array->data[array->used] = malloc(1 + length);
        if (array->data[array->used] != NULL)
            strcpy(array->data[array->used++], element);
    }
    else
        array->data[array->used++] = NULL;
}

void freeArray(Array *array) {
    size_t i;

    /* Free all the copies of the strings */
    for (i = 0; i < array->used; ++i)
        free(array->data[i]);

    free(array->data);
    free(array);
}

int main(void) {
    Array *array = NULL;

    array = malloc(sizeof(Array));
    if (array == NULL) {
        printf("Memory allocation issues\n");
        return -1;
    }
    initArray(array, 5); /* 5 lines */

    insertElement(array, "Test1");
    insertElement(array, "Test2");
    insertElement(array, "Test3");
    insertElement(array, "Test4");
    printf("%s\n", array->data[0]);
    printf("%s\n", array->data[1]);
    printf("%s\n", array->data[2]);
    printf("%s\n", array->data[3]);

    freeArray(array);

    return 0;
}