close(2) - Linux man page
Name
close - close a file descriptorSynopsis
#include <unistd.h> int close(int fd);
Description
If fd is the last copy of a particular file descriptor the resources associated with it are freed; if the descriptor was the last reference to a file which has been removed using unlink(2) the file is deleted.
Return Value
close() returns zero on success. On error, -1 is returned, and errno is set appropriately.Errors
- EBADF
- fd isn't a valid open file descriptor.
- EINTR
- The close() call was interrupted by a signal.
- EIO
- An I/O error occurred.
Conforming to
SVr4, 4.3BSD, POSIX.1-2001.Notes
Not checking the return value of close() is a common but nevertheless serious programming error. It is quite possible that errors on a previous write(2) operation are first reported at the final close(). Not checking the return value when closing the file may lead to silent loss of data. This can especially be observed with NFS and with disk quota.A successful close does not guarantee that the data has been successfully saved to disk, as the kernel defers writes. It is not common for a filesystem to flush the buffers when the stream is closed. If you need to be sure that the data is physically stored use fsync(2). (It will depend on the disk hardware at this point.)
