[BK-2020-03.git] / unitproc / bktemp-secondsUntilMidnight

#!/bin/bash
# Desc: Template to check that apps, files, or dirs exist.
# Author: Steven Baltaktei Sandoval; License: GPLv3+

#==BEGIN Define script parameters==
#===BEGIN Declare local script functions===
yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
die() { yell "$*"; exit 111; }
try() { "$@" || die "cannot $*"; }
timeUntilMidnight(){
    # Desc: Report seconds until midnight
    # Output: stdout: integer seconds until midnight
    # Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
    # Usage: timeUntilMidnight
    # Usage: if ! myTTL="$(timeUntilMidnight)"; then yell "ERROR in if statement"; exit 1; fi
    local returnState
    TIME_CURRENT="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
    TIME_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%dT%H%M%S%z)" # Produce separator-less current timestamp with resolution 1 second.
    DATE_CURRENT="$(date -d "$TIME_CURRENT" --iso-8601=date)" ; # Produce `date`-parsable current timestamp with resolution of 1 day.
    DATE_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%d)" ; # Produce separator-less current timestamp with resolution 1 day.
    DATE_TOMORROW="$(date -d "$TIME_CURRENT next day" --iso-8601=date)" ; # Produce timestamp of tomorrow's date (res. 1 day).
    TIME_NEXT_MIDNIGHT="$(date -d "$DATE_TOMORROW" --iso-8601=seconds)" ; # Produce `date`-parsable timestamp of closest future midnight (res. 1 second).
    SECONDS_UNTIL_NEXT_MIDNIGHT="$(( $(date +%s -d "$TIME_NEXT_MIDNIGHT") - $(date +%s -d "$TIME_CURRENT") ))" ; # Calculate seconds until closest future midnight (res. 1 second).
    if [[ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -gt 0 ]]; then
	returnState="true";
    elif [[ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -eq 0 ]]; then
	returnState="WARNING_ZERO";
	yell "WARNING:Reported time until midnight exactly zero.";
    elif [[ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -lt 0 ]]; then
	returnState="WARNING_NEGATIVE";
	yell "WARNING:Reported time until midnight is negative.";
    fi

    try echo "$SECONDS_UNTIL_NEXT_MIDNIGHT"; # Report
    
    #===Determine function return code===
    if [[ "$returnState" = "true" ]]; then
	return 0;
    elif [[ "$returnState" = "WARNING_ZERO" ]]; then
	return 1;
    elif [[ "$returnState" = "WARNING_NEGATIVE" ]]; then
	return 2;
    fi
} # Report seconds until next midnight
#===END Declare local script functions===
#==END Define script parameters==


#==BEGIN sample code==
try echo "Time until next midnight (seconds):$(timeUntilMidnight)" # simple report

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.
#==END sample code==
Commit	Line	Data
2ea4288a	1	#!/bin/bash
2ea4288a	2	# Desc: Template to check that apps, files, or dirs exist.
5ef33b04	3	# Author: Steven Baltaktei Sandoval; License: GPLv3+
2ea4288a SBS	4
	5	#==BEGIN Define script parameters==
	6	#===BEGIN Declare local script functions===
5ef33b04 SBS	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 $*"; }
2ea4288a SBS	10	timeUntilMidnight(){
2ea4288a SBS	11	# Desc: Report seconds until midnight
5ef33b04 SBS	12	# Output: stdout: integer seconds until midnight
	13	# Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
	14	# Usage: timeUntilMidnight
	15	# Usage: if ! myTTL="$(timeUntilMidnight)"; then yell "ERROR in if statement"; exit 1; fi
	16	local returnState
2ea4288a SBS	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).
5ef33b04 SBS	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 [[ "$returnState" = "WARNING_NEGATIVE" ]]; then
	42	return 2;
	43	fi
2ea4288a SBS	44	} # Report seconds until next midnight
	45	#===END Declare local script functions===
	46	#==END Define script parameters==
	47
	48
	49	#==BEGIN sample code==
5ef33b04 SBS	50	try echo "Time until next midnight (seconds):$(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.
2ea4288a	53	#==END sample code==