Great question! Here is a better explanation than I could write: https://www.joeshaw.org/dont-defer-close-on-writable-files https://www.joeshaw.org/dont-defer-

Great question! Here is a better explanation than I could write: https://www.joeshaw.org/dont-defer-close-on-writable-files https://www.joeshaw.org/dont-defer-close-on-writable-files In resume, man close(2), gives us the potential errors. This is the output for Ubuntu 20.04 LTS: EBADF fd isn't a valid open file descriptor. EINTR The close() call was interrupted by a signal; see signal(7). EIO An I/O error occurred. ENOSPC, EDQUOT On NFS, these errors are not normally reported against the first write which exceeds the available storage space, but instead against a subsequent write(2), fsync(2), or close().