qsort( ) on a structured array

I've searched online on the qsort( ) function and on this forum but cannot seem to find a lot of information on how to sort an array of structs. I seemed to get this code to compile but when I go to print out the array, it seems that the entire array is null. I've initialized the array already but didn't think anyone would need that. Here's only the code I'm having a problem with:

PHP Code:

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/* an entry in Operation Table */
struct ot_entry {
     char  ot_mnemonic[OP_LENGTH + 1];
     int   ot_format;
};

/* array of entries */
struct  ot_entry  *optbl[OT_SIZE];

int compare_elements(const void *ptr1, const void *ptr2){    
    return strcmp(((struct ot_entry*)ptr1)->ot_mnemonic, ((struct ot_entry*)ptr2)->ot_mnemonic);
}    

// sort Operation Table
void sortOpTbl(optbl){
    qsort(optbl, sizeof(struct ot_entry), ot_count, compare_elements);
}

int main(){
    
    sortOpTbl(optbl);
    
    return 0;   
} 


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Thanks in advance if anyone can help me figure out what I'm doing wrong.. :)

>>/* array of entries */
>>struct ot_entry *optbl[OT_SIZE];
This is not an array of structs, its an array of pointers to structs.

I assume you're actually assigning a value to these pointers? If not they'll most likely all be null (I'm assuming this array is a global variable?

The sortOpTbl should be like so:
void sortOpTbl(struct ot_entry optbl[])

The call to qsort is also incorrect.

Here is a sample, you code amended to run:
(I change the comparison to compare the ints rather than the char arrays, just to save time).

Code:

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

#define OP_LENGTH 10
#define OT_SIZE  10

/* an entry in Operation Table */
struct ot_entry
{
  char  ot_mnemonic[OP_LENGTH + 1];
  int  ot_format;
};

/* array of entries */
struct ot_entry optbl[OT_SIZE];

int compare_elements(const void *ptr1, const void *ptr2)
{
  return(((struct ot_entry *) ptr1)->ot_format - ((struct ot_entry *) ptr2)->ot_format);
}

// sort Operation Table
void sortOpTbl(struct ot_entry optbl[])
{
  qsort(optbl, OT_SIZE, sizeof(struct ot_entry), compare_elements);
}

int main(void)
{
  int i;
 
  for (i = 0; i < OT_SIZE; i++)
  {
    optbl[i].ot_format = 10 - i;
    printf ("%d ", optbl[i].ot_format);
  }
 
  sortOpTbl(optbl);
 
  printf ("\nAfter:\n");
 
  for (i = 0; i < OT_SIZE; i++)
  {
    printf ("%d ", optbl[i].ot_format);
  }
  return(0);
}

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Thanks a lot Hammer! I corrected my code and it works! :) Much appreciation...