ieee754.c

// gcc -std=c11 -g -O0 -Wall -Wextra -fdiagnostics-color=always ieee754.c

/*
$ ./a.out x 0 x inf -inf x nan -nan x 1 1.5 1.75 1.875 -1.875 x

0 00000000 00000000000000000000000 

0 11111111 00000000000000000000000 
1 11111111 00000000000000000000000 

0 11111111 10000000000000000000000 
1 11111111 10000000000000000000000 

0 01111111 00000000000000000000000 
0 01111111 10000000000000000000000 
0 01111111 11000000000000000000000 
0 01111111 11100000000000000000000 
1 01111111 11100000000000000000000 


*/

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

// for(var:range)
#define for_range_int(var,range) for(size_t var=0;var<sizeof(range)/sizeof(int);++var)
#define reinterpret(new_type,var) (*((new_type*)(&var)))

int main(int argc,char const *argv[]){

  for(int c=1;c<argc;++c){

    if(strcmp("x",argv[c])==0){
      printf("\n");
      continue;
    }

    float f=atof(argv[c]);

    int partition[]={1,8,23};
    for_range_int(part,partition){
      for(int i=0;i<partition[part];++i){
        printf( (reinterpret(uint32_t,f)&0x80000000) ? "1" : "0" );
        reinterpret(uint32_t,f)<<=1;
      }
      printf(" ");
    }

    printf("\n");

  }

  return 0;
}