TMPDIR is the canonical environment variable in Unix and POSIX1 that should be used to specify a temporary directory for scratch space. Most Unix programs will honor this setting and use its value to denote the scratch area for temporary files instead of the common default of /tmp23 or /var/tmp.4
Other forms sometimes accepted are TEMP, TEMPDIR and TMP, but these alternatives are used more commonly by non-POSIX operating systems or non-conformant programs.
TMPDIR is specified in various Unix and similar standards, e.g. per the Single UNIX Specification.5
References
References
- "Environment Variables". Pubs.opengroup.org. Retrieved 26 October 2017.
- "The Open Group Base Specifications Issue 7, IEEE Std 1003.1-2008, Base Definitions volume: Directory Structure and Files: /tmp". The Open Group. Retrieved 2011-04-02.
- "Filesystem Hierarchy Standard, version is 2.3: /tmp: Temporary files". Linux Foundation. Retrieved 2010-06-13.
- "Filesystem Hierarchy Standard, version is 2.3: /var/tmp: Temporary files preserved between system reboots". Linux Foundation. Retrieved 2010-06-13.
- "The Open Group Base Specifications Issue 7, IEEE Std 1003.1-2008, Base Definitions volume: Environment Variables: Other Environment Variables: TMPDIR". The Open Group. Retrieved 2011-04-02.