Characters: files

What happens when you type "123" in a text editor and save it to a file?

Characters '1', '2', '3' are stored in the file, not binary integer 123.

What if you type a series of 0's and 1's?

Still just characters

How can you write binary representation of data to a file?

hex editors allow you to type hexadecimal values like F3, 2A, etc. and store them as bytes

In C, use "b" in mode string with fopen to open the file

"rb": open for reading

"wb": open for writing

etc.