unitproc/bktemp-setTimeZoneEV

   1 #!/bin/bash
   2
   3 # Desc: Set time zone environment variable TZ
   4
   5 yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
   6 die() { yell "$*"; exit 111; }
   7 try() { "$@" || die "cannot $*"; }
   8 setTimeZoneEV(){
   9     # Desc: Set time zone environment variable TZ
  10     # Usage: setTimeZoneEV arg1
  11     # Input: arg1: 'date'-compatible timezone string (ex: "America/New_York")
  12     #        TZDIR env var (optional; default: "/usr/share/zoneinfo")
  13     # Output: exports TZ
  14     #         exit code 0 on success
  15     #         exit code 1 on incorrect number of arguments
  16     #         exit code 2 if unable to validate arg1
  17     # Depends: yell, printenv, bash 5
  18     # Tested on: Debian 10
  19     ARG1="$1"
  20     local tzDir returnState
  21     if ! [[ $# -eq 1 ]]; then
  22         yell "ERROR:Invalid argument count.";
  23         return 1;
  24     fi
  25
  26     # Read TZDIR env var if available
  27     if printenv TZDIR 1>/dev/null 2>&1; then
  28         tzDir="$(printenv TZDIR)";
  29     else
  30         tzDir="/usr/share/zoneinfo";
  31     fi
  32
  33     # Validate TZ string
  34     if ! [[ -f "$tzDir"/"$ARG1" ]]; then
  35         yell "ERROR:Invalid time zone argument.";
  36         return 2;
  37     else
  38     # Export ARG1 as TZ environment variable
  39         TZ="$ARG1" && export TZ && returnState="true";
  40     fi
  41
  42     # Determine function return code
  43     if [ "$returnState" = "true" ]; then
  44         return 0;
  45     fi
  46 } # Exports TZ environment variable
  47
  48 #==BEGIN sample code==
  49 date --iso-8601=seconds; echo "==============="; sleep 2
  50
  51 date --iso-8601=seconds
  52 cmd1="setTimeZoneEV America/New_York"
  53 echo "Running:$cmd1"; $cmd1; echo "Exit code:$?"
  54 date --iso-8601=seconds; echo "==============="; sleep 2
  55
  56 date --iso-8601=seconds
  57 cmd2="setTimeZoneEV Asia/Tokyo"
  58 echo "Running:$cmd2"; $cmd2; echo "Exit code:$?"
  59 date --iso-8601=seconds; echo "==============="; sleep 2
  60
  61 date --iso-8601=seconds
  62 cmd3="setTimeZoneEV";
  63 echo "Running:$cmd3"; $cmd3; echo "Exit code:$?"
  64 date --iso-8601=seconds; echo "==============="; sleep 2
  65
  66 date --iso-8601=seconds
  67 cmd4="setTimeZoneEV Pacific/Lemuria"
  68 echo "Running:$cmd4"; $cmd4; echo "Exit code:$?"
  69 date --iso-8601=seconds; echo "==============="; sleep 2
  70 #==END sample code==
  71
  72 # Author: Steven Baltakatei Sandoval
  73 # License: GPLv3+
  74
  75