style(unitproc):timeUntilNextHour: VAR_NAMES to VarNames
[BK-2020-03.git] / unitproc / bktemp-timeUntilNextDay
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1#!/bin/bash
2# Desc: Template to report seconds until beginning of next day
3
4#==BEGIN Define script parameters==
5#===BEGIN Declare local script functions===
6yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
7die() { yell "$*"; exit 111; }
8try() { "$@" || die "cannot $*"; }
9timeUntilNextDay(){
10 # Desc: Report seconds until next day.
11 # Version: 1.0.3
12 # Output: stdout: integer seconds until next day
13 # Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
14 # Usage: timeUntilNextDay
15 # Usage: if ! myTTL="$(timeUntilNextDay)"; then yell "ERROR in if statement"; exit 1; fi
16 # Depends: date 8, echo 8, yell, try
17
18 local returnState timeCurrent timeNextDay secondsUntilNextDay
19 timeCurrent="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
20 timeNextDay="$(date -d "$timeCurrent next day" --iso-8601=date)"; # Produce timestamp of beginning of tomorrow with resolution of 1 second.
21 secondsUntilNextDay="$(( $(date +%s -d "$timeNextDay") - $(date +%s -d "$timeCurrent") ))" ; # Calculate seconds until closest future midnight (res. 1 second).
22 if [[ "$secondsUntilNextDay" -gt 0 ]]; then
23 returnState="true";
24 elif [[ "$secondsUntilNextDay" -eq 0 ]]; then
25 returnState="warning_zero";
26 yell "WARNING:Reported time until next day exactly zero.";
27 elif [[ "$secondsUntilNextDay" -lt 0 ]]; then
28 returnState="warning_negative";
29 yell "WARNING:Reported time until next day is negative.";
30 fi
31
32 try echo "$secondsUntilNextDay"; # Report
33
34 # Determine function return code
35 if [[ "$returnState" = "true" ]]; then
36 return 0;
37 elif [[ "$returnState" = "warning_zero" ]]; then
38 return 1;
39 elif [[ "$returnState" = "warning_negative" ]]; then
40 return 2;
41 fi
42} # Report seconds until next day
43#===END Declare local script functions===
44#==END Define script parameters==
45
46
47#==BEGIN sample code==
48try echo "Time until next day (seconds):$(timeUntilNextDay)" # simple report
49
50if ! myTTL="$(timeUntilNextDay)"; then yell "ERROR in if statement for myTTL:$myTTL"; exit 1; fi # Use of exit code to exit early if time <= 0.
51#==END sample code==
52
53# Author: Steven Baltaktei Sandoval
54# License: GPLv3+