Question

I am reading/writing chars to a binary file. The program doing the reading/writing may run on either a 32 or 64 bit machine. Furthermore, the file could be written in a 32-bit environment then read in 64 and vice-versa.

Therefore I need some way of storing chars that guarantees a certain width (the smaller the better). I’m sure there is an accepted/common way to do this, but being a C novice I don’t know it, and also can’t find anything via google..

Does any one know the trick?

Answer 1

On any “normal” modern architecture chars are always of 8 bits, regardless of 64/32 bit issues. Those arise when you dump directly on a file the binary representation of int or other types (which can vary in size and byte ordering depending on architecture), but plain chars should be safe.

… obviously if you are writing text you should choose some encoding, but that’s a completely different story…