Sorting strings with qsort does not work - c++

Question

I have a program, that asks several strings and should sort them.
My code is:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define MAX_STR_LEN 256
int myStrCmp (const void * a, const void * b)
{
return strcmp((const char *)a, (const char *)b);
}
int main(void)
{
int strNum; // expected number of input strings
int strCnt; // counter of strings
char ** storage; // pointr to the memory when strings are stored
char strBuf[ MAX_STR_LEN]; // buffer for strings
char * strPtr;
// input of strings number
do{
printf("How many strings will be entered: ");
while( scanf("%d", &strNum) != 1)
{
printf("ERROR: Not number was entered!\n");
while( getchar() != '\n' );
printf("Please enter a number: ");
}
if( strNum < 2 )
{
printf("ERROR: Number less than 2 was entered!\n");
}
while( getchar() != '\n' );
}
while(strNum < 2);
// allocation of memory for pointers
storage = (char **) calloc(strNum, sizeof(char*) );
if( storage == NULL )
{
printf("ERROR: Unexpected problems with memory allocation!\n");
return 1;
}
// input of strings
for( strCnt = 0; strCnt < strNum; strCnt++)
{
printf("Enter string #%d:\n", strCnt + 1);
fgets(strBuf, MAX_STR_LEN, stdin);
strPtr = strchr(strBuf, '\n');
if( strPtr )
{
*strPtr = '\0';
}
else
{
strBuf[ MAX_STR_LEN - 1] = '\0';
}
// allocation memory for particular string
storage[strCnt] = (char *) malloc(strlen(strBuf) + 1);
if(storage[strCnt] == NULL)
{
printf("ERROR: Unexpected problems with memory allocation!\n");
return 2;
}
// move string to dynamic memory
strcpy(storage[strCnt], strBuf);
}
// sort the strings
qsort(storage, strNum, sizeof(char**), myStrCmp);
// output the result
printf("\nSorted strings:\n");
for( strCnt = 0; strCnt < strNum; strCnt++)
{
printf("%s\n", storage[strCnt]);
}
return 0;
}
The simplest test shows the trouble:
How many strings will be entered: 3
Enter string #1:
ddd
Enter string #2:
aaa
Enter string #3:
ccc
Sorted strings:
ddd
aaa
ccc
I have tryed Visual C++ and gcc, but the result is the same. Please, say me what is wrong in the code?

Answer 1

The problem is in myStrCmp function.
Because a and b are elements in not a simple array, but in array of pointers, their type must be char ** and function that compares two elements have to be as follows:
int myStrCmp (const void * a, const void * b)
{
return strcmp(*(const char **)a, *(const char **)b);
}