I want to read and write numbers between files and memory in a byte-at-a-time way, not as formatted characters the way fprintf and fscanf do. How can I do this?
What you’re trying to do is usually called “binary” I/O. First, make sure that you are calling fopen with the “b” modifier (“rb”, “wb”, etc.; see question 12.38). Then, use the & and sizeof operators to get a handle on the sequences of bytes you are trying to transfer. Usually, the fread and fwrite functions are what you want to use; see question 2.11 for an example. Note, though, that fread and fwrite do not necessarily imply binary I/O. If you’ve opened a file in binary mode, you can use any I/O calls on it (see for example the examples in question 12.42); if you’ve opened it in text mode, you can use fread or fwrite if they’re convenient. Finally, note that binary data files are not very portable; see question 20.5. See also question 12.40. comp.lang.c FAQ list ยท Question 12.38 Q: How can I read a binary data file properly? I’m occasionally seeing 0x0a and 0x0d values getting garbled, and I seem to hit EOF prematurely if the data contains the value 0x1a. A: When you’re reading a b
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