Configuration Information [Automatically generated, do not change]: Machine: x86_64 OS: darwin17.7.0 Compiler: clang Compilation CFLAGS: -g -O2 -Wno-parentheses -Wno-format-security uname output: Darwin f638f97d 18.6.0 Darwin Kernel Version 18.6.0: Thu Apr 25 23:16:27 PD$ Machine Type: x86_64-apple-darwin17.7.0
Bash Version: 5.0 Patch Level: 7 Release Status: release *Description:* I've noticed that a timezone explicitly set in the TZ environment variable can get cached (if any date-using command/builtin is run) and then show up (at least) in dates produced by the printf builtin's "%(...)T" formats even after the TZ variable is unset. I played around with this for a bit and identified two ways to get the timezone to re-set: - Run an external command. I have yet to find an external command that didn't correct it, so I suspect this behavior is intrinsic to the API calls made when running an external command. It's also possible I'm too unimaginative to find an external command that *doesn't* invoke date APIs :). - Set the TZ variable inline and run any builtin (i.e., `TZ=:/etc/localtime :`). *Repeat-By:* ---- tzcache.sh ---- echo $BASH_VERSION export TZ=Antarctica/South_Pole printf "TZ: $TZ\n\t%(%+)T\n" unset TZ # still prints the now-unset timezone printf "TZ: $TZ\n\t%(%+)T\n" # to reset it # run any external command # or any builtin with an inline TZ setting TZ=:/etc/localtime : printf "TZ: $TZ\n\t%(%+)T\n" -------------------- $ env -i $(which bash) --norc --noprofile tzcache.sh 5.0.7(1)-release TZ: Antarctica/South_Pole Sun Jul 14 05:21:49 NZST 2019 TZ: Sun Jul 14 05:21:49 NZST 2019 TZ: Sat Jul 13 12:21:49 CDT 2019 Cheers, Travis
