Package: bash Version: 4.4-5 According to the man page:
UID Expands to the user ID of the current user, initialized at shell startup. This variable is readonly. However, if the variable is set in the environment then it will inherit it from there rather than initializing it during startup. The same is true of EUID and perhaps others. $ bash -c 'echo $UID' 1000 $ env UID=spong bash -c 'echo $UID' spong The example is contrived but the issue has a real impact, for example: http://aptosid.com/index.php?name=PNphpBB2&file=viewtopic&t=2985 ttfn/rjk