c - Converting little endian to big endian using Bitshift Operators -

i working on endianess. little endian program works, , gives correct output. not able way around big endian. below have far. know have use bit shift , dont think doing job @ it. tried asking ta's , prof not help. have been following link (convert big endian little endian in c [without using provided func]) understand more cannot still make work. thank help.

#include <stdio.h> #include <stdlib.h>  int main(int argc, char *argv[]) {     file* input;     file* output;      input = fopen(argv[1],"r");     output = fopen(argv[2],"w");     int value,value2;     int i;     int zipcode, population;     while(fscanf(input,"%d %d\n",&zipcode, &population)!= eof)     {         for(i = 0; i<4; i++)         {         population = ((population >> 4)|(population << 4));         }         fwrite(&population, sizeof(int), 1, output);     }      fclose(input);           fclose(output);      return 0; }    

i'm answering not give answer solve yourself.

first ask this: how many bits in byte? (hint: 8) next, how many bytes in int? (hint: 4) picture 32-bit integer in memory:

  +--------+ 0x|12345678|   +--------+ 

now picture on little-endian machine, byte-wise. this:

  +--+--+--+--+ 0x|78|56|34|12|   +--+--+--+--+ 

what shift operations required bytes correct spot?

remember, when use bitwise operator >>, operating on bits. 1 << 24 integer value 1 converted processor's opposite endianness.