Writes a generated file so that a link planted at the target cannot redirect the write: the content
goes to a new temporary file in the same folder and is renamed over the target. rename replaces
the directory entry (a symbolic link is replaced, never followed), so there is no moment between a
check and the write at which a link can take effect; the result is checked afterwards. A hard link
is not written through either: the other name keeps the old content. A folder at the target is
reported in plain words instead of as a raw EISDIR.
Writes a generated file so that a link planted at the target cannot redirect the write: the content goes to a new temporary file in the same folder and is renamed over the target.
renamereplaces the directory entry (a symbolic link is replaced, never followed), so there is no moment between a check and the write at which a link can take effect; the result is checked afterwards. A hard link is not written through either: the other name keeps the old content. A folder at the target is reported in plain words instead of as a raw EISDIR.