Op 02-11-16 om 13:32 schreef Martijn Dekker: > If both 'mkdir' and 'ln' operate atomically, there could be a safe > workaround for creating a regular file directly under /tmp. It would > involve creating a (very) temporary directory under /tmp using 'mkdir > -m700', then creating the file inside there, setting the mode, etc. with > no need for atomicity, then attempting to 'ln' that file back to /tmp > until we've got an available name. Do you think this could work?
No one replied to poke holes in this, so I went ahead and implemented this workaround in the modernish shell library implementation of 'mktemp'. <https://github.com/modernish/modernish> Just one thing still worries me a bit. Though 'ln' without the -f option is never supposed to overwrite files, the spec also states: | If the last operand specifies an existing file of a type not | specified by the System Interfaces volume of POSIX.1-2008, the | behavior is implementation-defined. http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ln.html Does this mean I cannot actually rely on 'ln' not overwriting a file or otherwise behaving unexpectedly? Thanks, - M.
