#include <stdio.h>
#include <fstream>      // std::fstream
#include <stdio.h>
#include <string.h>


char Header      [0x200];
char Elf32Magic  [20] = "\x7f\x45\x4c\x46\01";  //7F 45 4C 46  01 // ELF32 
char Elf64Magic  [20] = "\x7f\x45\x4c\x46\02";  //7F 45 4C 46  02 // ELF64
char Win32Magic  [20] = "\x50\x45\x00\x00\x4C\x01";// PE32
char Win64Magic  [20] = "\x50\x45\x00\x00\x64\x86";// PE64

char PeHeader[20] = {};
void CheckWinHeader(){
  int k = 0;
  for (int i = 0; i < 0x200; i++)
  {
   if(Header[i] == 0x50 && Header[i+1] == 0x45) // PE     
     {

      for(int j = i; j < i + 6; j++)
      {
        PeHeader[k] = Header[j];
        k++;
       //printf("%hhx", Header[j]); 
      }
     }
  }
}




int main(){
  std::fstream fs; 
  fs.open ("/home/PATH/TO/YOUR/BINARY", std::fstream::in | std::fstream::out | std::fstream::app);
  fs.read( Header , 0x200);
 
  if(memcmp ( Header, Elf32Magic, 5 ) == 0 ){
   printf("ELF 32 Match Found ! \n");
   }
  if(memcmp ( Header, Elf64Magic, 5 ) == 0 ){
   printf("Elf 64 Match Found ! \n");
   }

  CheckWinHeader();

  if(memcmp ( &PeHeader, Win32Magic, 6 ) == 0 ){
   printf("Win 32 Match Found ! \n");
   }

  if(memcmp ( &PeHeader, Win64Magic, 6 ) == 0 ){
   printf("Win 64 Match Found ! \n");
   }

 fs.close();
 return 0;
}

#include <stdio.h>
#include <fstream>      // std::fstream
#include <stdio.h>
#include <string.h>


char Header      [0x200];
char Elf32Magic  [20] = "\x7f\x45\x4c\x46\01";  //7F 45 4C 46  01 // ELF32 
char Elf64Magic  [20] = "\x7f\x45\x4c\x46\02";  //7F 45 4C 46  02 // ELF64
char Win32Magic  [20] = "\x50\x45\x00\x00\x4C\x01";// PE32
char Win64Magic  [20] = "\x50\x45\x00\x00\x64\x86";// PE64

char PeHeader[20] = {};
void CheckWinHeader(){
  int k = 0;
  for (int i = 0; i < 0x200; i++)
  {
   if(Header[i] == 0x50 && Header[i+1] == 0x45) // PE     
     {

      for(int j = i; j < i + 6; j++)
      {
        PeHeader[k] = Header[j];
        k++;
       //printf("%hhx", Header[j]); 
      }
     }
  }
}


int main(){
  std::fstream fs; 
  fs.open ("/home/PATH/TO/YOUR/BINARY", std::fstream::in | std::fstream::out | std::fstream::app);
  fs.read( Header , 0x200);
 
  if(memcmp ( Header, Elf32Magic, 5 ) == 0 ){
    printf("ELF 32 Match Found ! \n");
  }
  if(memcmp ( Header, Elf64Magic, 5 ) == 0 ){
    printf("Elf 64 Match Found ! \n");
  }

  CheckWinHeader();

  if(memcmp ( &PeHeader, Win32Magic, 6 ) == 0 ){
    printf("Win 32 Match Found ! \n");
  }

  if(memcmp ( &PeHeader, Win64Magic, 6 ) == 0 ){
    printf("Win 64 Match Found ! \n");
  }

 fs.close();
 return 0;
}

I know they are many answers here, but none of them are really portable and require some kind of tool to use. I wanted to solve this in a programmatic way for all platforms . This will work on anything with a C compiler.

#include <stdio.h>
#include <fstream>      // std::fstream
#include <stdio.h>
#include <string.h>


char Header      [0x200];
char Elf32Magic  [20] = "\x7f\x45\x4c\x46\01";  //7F 45 4C 46  01 // ELF32 
char Elf64Magic  [20] = "\x7f\x45\x4c\x46\02";  //7F 45 4C 46  02 // ELF64
char Win32Magic  [20] = "\x50\x45\x00\x00\x4C\x01";// PE32
char Win64Magic  [20] = "\x50\x45\x00\x00\x64\x86";// PE64

char PeHeader[20] = {};
void CheckWinHeader(){
  int k = 0;
  for (int i = 0; i < 0x200; i++)
  {
   if(Header[i] == 0x50 && Header[i+1] == 0x45) // PE     
     {

      for(int j = i; j < i + 6; j++)
      {
        PeHeader[k] = Header[j];
        k++;
       //printf("%hhx", Header[j]); 
      }
     }
  }
}




int main(){
  std::fstream fs; 
  fs.open ("/home/PATH/TO/YOUR/BINARY", std::fstream::in | std::fstream::out | std::fstream::app);
  fs.read( Header , 0x200);
 
  if(memcmp ( Header, Elf32Magic, 4 ) == 0 ){
   printf("ELF 32 Match Found ! \n");
   }
  if(memcmp ( Header, Elf64Magic, 4 ) == 0 ){
   printf("Elf 64 Match Found ! \n");
   }

  CheckWinHeader();

  if(memcmp ( &PeHeader, Win32Magic, 6 ) == 0 ){
   printf("Win 32 Match Found ! \n");
   }

  if(memcmp ( &PeHeader, Win64Magic, 6 ) == 0 ){
   printf("Win 64 Match Found ! \n");
   }

 fs.close();
 return 0;
}

compile by using any compiler . I used g++.

g++ Bincheck.cpp -o bincheck
./bincheck

I know they are many answers here, but none of them are really portable and require some kind of tool to use. I wanted to solve this in a programmatic way for all platforms . This will work on anything with a C compiler.

#include <stdio.h>
#include <fstream>      // std::fstream
#include <stdio.h>
#include <string.h>


char Header      [0x200];
char Elf32Magic  [20] = "\x7f\x45\x4c\x46\01";  //7F 45 4C 46  01 // ELF32 
char Elf64Magic  [20] = "\x7f\x45\x4c\x46\02";  //7F 45 4C 46  02 // ELF64
char Win32Magic  [20] = "\x50\x45\x00\x00\x4C\x01";// PE32
char Win64Magic  [20] = "\x50\x45\x00\x00\x64\x86";// PE64

char PeHeader[20] = {};
void CheckWinHeader(){
  int k = 0;
  for (int i = 0; i < 0x200; i++)
  {
   if(Header[i] == 0x50 && Header[i+1] == 0x45) // PE     
     {

      for(int j = i; j < i + 6; j++)
      {
        PeHeader[k] = Header[j];
        k++;
       //printf("%hhx", Header[j]); 
      }
     }
  }
}




int main(){
  std::fstream fs; 
  fs.open ("/home/PATH/TO/YOUR/BINARY", std::fstream::in | std::fstream::out | std::fstream::app);
  fs.read( Header , 0x200);
 
  if(memcmp ( Header, Elf32Magic, 5 ) == 0 ){
   printf("ELF 32 Match Found ! \n");
   }
  if(memcmp ( Header, Elf64Magic, 5 ) == 0 ){
   printf("Elf 64 Match Found ! \n");
   }

  CheckWinHeader();

  if(memcmp ( &PeHeader, Win32Magic, 6 ) == 0 ){
   printf("Win 32 Match Found ! \n");
   }

  if(memcmp ( &PeHeader, Win64Magic, 6 ) == 0 ){
   printf("Win 64 Match Found ! \n");
   }

 fs.close();
 return 0;
}

compile by using any compiler . I used g++.

g++ Bincheck.cpp -o bincheck
./bincheck