Question

The write function does not print a floating point number in the following code:

#include <unistd.h>

int main(){

    float f = 4.5;

    write(1,&f,sizeof float);

    return 0;
}

This results in:

�@

Whereas:

int main(){

    char *c = "Hello world";

    write (1,c,strlen(c)+1);

    return 0;
}

Prints Hello world as expected.

What am I missing?

Thanks in advance.

Answer 1

write outputs the bytes in the binary representation of the floating-point number. Those bytes do not even always correspond to readable characters, let alone to the textual representation of the number itself.

I guess you want to convert the number to human-readable text. That’s what printf is for:

printf("%f", f);