FILE *file; 
struct catalog{char 1rst_field,2nd_field,3rd_field}name,v[100]; 
 
//here i put the data in the file 
 
typedef int(*fcmp)(const void*,const void*) 
cmp1rst_field(catalog a1,catalog a2) 
{return a1.1rst_field-a2.1rst_field} 
int a[100],n=100,i; 
 
void sort() 
{ 
while(!feof(file)) 
 
//here i'd have to put the data from 1rst_field in a[i];i++; 
 
qsort(&a[0],n,sizeof (int),(fcmp)cmp1rst_field)
}