Question

Need help programming in C:

Write a program the writes several floating-point values
to a file in binary. {Use a type other than float.}
- look at the size of the file to see if it matches the
size and number of floating-point values written.

Answer 1

Yoo sup finally a C question. In c++ this is trivial, use the iostream library. C, well, still fairly trivial. Use fopen to open a file and pass "b" to open the file in binary, fopen will return the file handle. Then try the write, you'll need that file handle again, try the man pages for more details; http://linux.die.net/man/3/fwrite

Now, "use a type other than float." I'm pretty sure this is referring to him wanting you to use a double. I assume it's this because an alternative to using write is using fprintf, and since fprintf is a variadic function the floats will be promoted to doubles (since the types are not prototyped). Check 6.5.2.2 line 6 in the C99 draft if you want to learn more about it. Basically the file size would be 8 bytes, the float would be 4 bytes, and confusion ensues if you are unaware of this weird property.