I’m doing a small project in C after quite a long time away from it. These happen to include some file handling. I noticed in various documentation that there are functions which return FILE * handles and others which return (small integer) descriptors. Both sets of functions offer the same basic services I need so it really does not matter I use.
But I’m curious about the collection wisdom: is it better to use fopen() and friends, or open() and friends?
Edit Since someone mentioned buffered vs unbuffered and accessing devices, I should add that one part of this small project will be writing a userspace filesystem driver under FUSE. So the file level access could as easily be on a device (e.g. a CDROM or a SCSI drive) as on a ‘file’ (i.e. an image).
The objection that ‘fopen’ is portable and ‘open’ isn’t is bogus.
fopen is part of libc, open is a POSIX system call.
Each is as portable as the place they come from.
i/o to fopen’ed files is (you must assume it may be, and for practical purposes, it is) buffered by libc, file descriptors open()’ed are not buffered by libc (they may well be, and usually are buffered in the filesystem — but not everything you open() is a file on a filesystem.
What’s the point of fopen’ing, for example, a device node like /dev/sg0, say, or /dev/tty0… What are you going to do? You’re going to do an ioctl on a FILE *? Good luck with that.
Maybe you want to open with some flags like O_DIRECT — makes no sense with fopen().