31 Input/output library [input.output]

31.12 File systems [filesystems]

31.12.13 Filesystem operation functions [fs.op.funcs] General [fs.op.funcs.general]

Filesystem operation functions query or modify files, including directories, in external storage.
[Note 1: 
Because hardware failures, network failures, file system races ([fs.race.behavior]), and many other kinds of errors occur frequently in file system operations, any filesystem operation function, no matter how apparently innocuous, can encounter an error; see [fs.err.report].
— end note]