unitproc/bktemp-timeUntilNextDay

   1 #!/bin/bash
   2 # Desc: Template to report seconds until beginning of next day
   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 $*"; }
  10 timeUntilNextDay(){
  11     # Desc: Report seconds until next day.
  12     # Output: stdout: integer seconds until next day
  13     # Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
  14     # Usage: timeUntilNextDay
  15     # Usage: if ! myTTL="$(timeUntilNextDay)"; then yell "ERROR in if statement"; exit 1; fi
  16     local returnState TIME_CURRENT TIME_NEXT_DAY SECONDS_UNTIL_NEXT_DAY
  17     TIME_CURRENT="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
  18     TIME_NEXT_DAY="$(date -d "$TIME_CURRENT next day" --iso-8601=date)"; # Produce timestamp of beginning of tomorrow with resolution of 1 second.
  19     SECONDS_UNTIL_NEXT_DAY="$(( $(date +%s -d "$TIME_NEXT_DAY") - $(date +%s -d "$TIME_CURRENT") ))" ; # Calculate seconds until closest future midnight (res. 1 second).
  20     if [[ "$SECONDS_UNTIL_NEXT_DAY" -gt 0 ]]; then
  21         returnState="true";
  22     elif [[ "$SECONDS_UNTIL_NEXT_DAY" -eq 0 ]]; then
  23         returnState="WARNING_ZERO";
  24         yell "WARNING:Reported time until next day exactly zero.";
  25     elif [[ "$SECONDS_UNTIL_NEXT_DAY" -lt 0 ]]; then
  26         returnState="WARNING_NEGATIVE";
  27         yell "WARNING:Reported time until next day is negative.";
  28     fi
  29
  30     try echo "$SECONDS_UNTIL_NEXT_DAY"; # Report
  31
  32     #===Determine function return code===
  33     if [[ "$returnState" = "true" ]]; then
  34         return 0;
  35     elif [[ "$returnState" = "WARNING_ZERO" ]]; then
  36         return 1;
  37     elif [[ "$returnState" = "WARNING_NEGATIVE" ]]; then
  38         return 2;
  39     fi
  40 } # Report seconds until next day
  41 #===END Declare local script functions===
  42 #==END Define script parameters==
  43
  44
  45 #==BEGIN sample code==
  46 try echo "Time until next day (seconds):$(timeUntilNextDay)" # simple report
  47
  48 if ! myTTL="$(timeUntilNextDay)"; then yell "ERROR in if statement for myTTL:$myTTL"; exit 1; fi # Use of exit code to exit early if time <= 0.
  49 #==END sample code==