unitproc/bktemp-secondsUntilMidnight

   1 #!/bin/bash
   2 # Desc: Template to check that apps, files, or dirs exist.
   3 # Author: Steven Baltaktei Sandoval; License: GPLv3+
   4
   5 #==BEGIN Define script parameters==
   6 #===BEGIN Declare local script functions===
   7 yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
   8 die() { yell "$*"; exit 111; }
   9 try() { "$@" || die "cannot $*"; }
  10 timeUntilMidnight(){
  11     # Desc: Report seconds until midnight
  12     # Output: stdout: integer seconds until midnight
  13     # Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
  14     # Usage: timeUntilMidnight
  15     # Usage: if ! myTTL="$(timeUntilMidnight)"; then yell "ERROR in if statement"; exit 1; fi
  16     local returnState
  17     TIME_CURRENT="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
  18     TIME_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%dT%H%M%S%z)" # Produce separator-less current timestamp with resolution 1 second.
  19     DATE_CURRENT="$(date -d "$TIME_CURRENT" --iso-8601=date)" ; # Produce `date`-parsable current timestamp with resolution of 1 day.
  20     DATE_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%d)" ; # Produce separator-less current timestamp with resolution 1 day.
  21     DATE_TOMORROW="$(date -d "$TIME_CURRENT next day" --iso-8601=date)" ; # Produce timestamp of tomorrow's date (res. 1 day).
  22     TIME_NEXT_MIDNIGHT="$(date -d "$DATE_TOMORROW" --iso-8601=seconds)" ; # Produce `date`-parsable timestamp of closest future midnight (res. 1 second).
  23     SECONDS_UNTIL_NEXT_MIDNIGHT="$(( $(date +%s -d "$TIME_NEXT_MIDNIGHT") - $(date +%s -d "$TIME_CURRENT") ))" ; # Calculate seconds until closest future midnight (res. 1 second).
  24     if [[ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -gt 0 ]]; then
  25         returnState="true";
  26     elif [[ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -eq 0 ]]; then
  27         returnState="WARNING_ZERO";
  28         yell "WARNING:Reported time until midnight exactly zero.";
  29     elif [[ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -lt 0 ]]; then
  30         returnState="WARNING_NEGATIVE";
  31         yell "WARNING:Reported time until midnight is negative.";
  32     fi
  33
  34     try echo "$SECONDS_UNTIL_NEXT_MIDNIGHT"; # Report
  35
  36     #===Determine function return code===
  37     if [[ "$returnState" = "true" ]]; then
  38         return 0;
  39     elif [[ "$returnState" = "WARNING_ZERO" ]]; then
  40         return 1;
  41     elif [[ "$returnState" = "WARNING_NEGATIVE" ]]; then
  42         return 2;
  43     fi
  44 } # Report seconds until next midnight
  45 #===END Declare local script functions===
  46 #==END Define script parameters==
  47
  48
  49 #==BEGIN sample code==
  50 try echo "Time until next midnight (seconds):$(timeUntilMidnight)" # simple report
  51
  52 if ! myTTL="$(timeUntilMidnight)"; then yell "ERROR in if statement for myTTL:$myTTL"; exit 1; fi # Use of exit code to exit early if time <= 0.
  53 #==END sample code==