May 2, 2026
Tempers flare over TEMP
Why are there both TMP and TEMP environment variables, and which one is right?
The internet is fighting over two tiny folder names, and the old computer nerds are loving it
TLDR: Both names exist because early software developers never agreed on one place for temporary files, and Microsoft later backed TEMP without ending the chaos. Commenters loved the retro weirdness but argued hard over the history lesson, with some nostalgic and others loudly calling the timeline messy.
A delightfully tiny mystery — why some computers have both TMP and TEMP for temporary files — turned into a full-blown nostalgia brawl in the comments. The article’s basic answer is simple: long ago, different programs picked different names for the same job, and when old PC software makers failed to agree, both versions survived. Later, Microsoft’s command system picked TEMP, but plenty of apps kept doing their own thing, so the double-name mess never died.
But honestly? The real show was the crowd. One camp treated this like a charming fossil from the dawn of personal computing, with commenters reminiscing about the wild old days when you literally patched bytes by hand just to configure software. That sent readers into a mix of awe and "wait, you had to do WHAT?" energy. Another camp came in swinging with fact-check fury, calling out the article’s timeline and saying the CP/M backstory was either off, overhyped, or just plain confusing. One commenter basically yelled, "I love this writer, but come on," while another complained the history lesson promised importance and then wandered off.
There was also some nerd-comedy gold: one reader guessed TMP won fans simply because old file endings were only three letters long, which feels exactly like the kind of accidental rule that becomes permanent. The community verdict? A classic tech soap opera: tiny choice, gigantic legacy, and everyone has notes.
Key Points
- •The article traces TMP and TEMP back to early operating-system history rather than a single formal standard.
- •CP/M did not have environment variables, so programs used executable patching or other program-specific configuration for settings such as temporary-file locations.
- •MS-DOS introduced environment variables, but early MS-DOS applications often ignored them because many were ports of CP/M software.
- •As MS-DOS-native software spread, both TEMP and TMP emerged independently as conventions for temporary-file directories.
- •MS-DOS 2.0 used the TEMP variable for temporary files created to simulate piping, but many other programs continued to use either TEMP or TMP, and some checked both.