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

#!/bin/bash
# Desc: Template to report seconds until beginning of next hour
# 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 $*"; }
timeUntilNextHour(){
    # Desc: Report seconds until next hour
    # Output: stdout: integer seconds until next hour
    # Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
    # Usage: timeUntilNextHour
    # Usage: if ! myTTL="$(timeUntilNextHour)"; then yell "ERROR in if statement"; exit 1; fi
    local returnState
    local TIME_CURRENT="$(date --iso-8601=seconds)"; # Produce `date`-parsable current timestamp with resolution of 1 second.
    local TIME_NEXT_HOUR="$(date -d "$TIME_CURRENT next hour" --iso-8601=hours)"; # Produce `date`-parsable current time stamp with resolution of 1 second.
    local SECONDS_UNTIL_NEXT_HOUR="$(( $(date +%s -d "$TIME_NEXT_HOUR") - $(date +%s -d "$TIME_CURRENT") ))"; # Calculate seconds until closest future midnight (res. 1 second).
    if [[ "$SECONDS_UNTIL_NEXT_HOUR" -gt 0 ]]; then
	returnState="true";
    elif [[ "$SECONDS_UNTIL_NEXT_HOUR" -eq 0 ]]; then
	returnState="WARNING_ZERO";
	yell "WARNING:Reported time until next hour exactly zero.";
    elif [[ "$SECONDS_UNTIL_NEXT_HOUR" -lt 0 ]]; then
	returnState="WARNING_NEGATIVE";
	yell "WARNING:Reported time until next hour is negative.";
    fi

    try echo "$SECONDS_UNTIL_NEXT_HOUR"; # 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 hour (seconds):$(timeUntilNextHour)" # simple report

if ! myTTL="$(timeUntilNextHour)"; then yell "ERROR in if statement for myTTL:$myTTL"; exit 1; fi # Use of exit code to exit early if time <= 0.
#==END sample code==
Commit	Line	Data
f7301210 SBS	1	#!/bin/bash
	2	# Desc: Template to report seconds until beginning of next hour
	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 $*"; }
	10	timeUntilNextHour(){
	11	# Desc: Report seconds until next hour
	12	# Output: stdout: integer seconds until next hour
	13	# Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
	14	# Usage: timeUntilNextHour
	15	# Usage: if ! myTTL="$(timeUntilNextHour)"; then yell "ERROR in if statement"; exit 1; fi
	16	local returnState
	17	local TIME_CURRENT="$(date --iso-8601=seconds)"; # Produce `date`-parsable current timestamp with resolution of 1 second.
	18	local TIME_NEXT_HOUR="$(date -d "$TIME_CURRENT next hour" --iso-8601=hours)"; # Produce `date`-parsable current time stamp with resolution of 1 second.
	19	local SECONDS_UNTIL_NEXT_HOUR="$(( $(date +%s -d "$TIME_NEXT_HOUR") - $(date +%s -d "$TIME_CURRENT") ))"; # Calculate seconds until closest future midnight (res. 1 second).
	20	if [[ "$SECONDS_UNTIL_NEXT_HOUR" -gt 0 ]]; then
	21	returnState="true";
	22	elif [[ "$SECONDS_UNTIL_NEXT_HOUR" -eq 0 ]]; then
	23	returnState="WARNING_ZERO";
	24	yell "WARNING:Reported time until next hour exactly zero.";
	25	elif [[ "$SECONDS_UNTIL_NEXT_HOUR" -lt 0 ]]; then
	26	returnState="WARNING_NEGATIVE";
	27	yell "WARNING:Reported time until next hour is negative.";
	28	fi
	29
	30	try echo "$SECONDS_UNTIL_NEXT_HOUR"; # 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 [[ "$returnState" = "WARNING_NEGATIVE" ]]; then
	38	return 2;
	39	fi
	40	} # Report seconds until next midnight
	41	#===END Declare local script functions===
	42	#==END Define script parameters==
	43
	44
	45	#==BEGIN sample code==
	46	try echo "Time until next hour (seconds):$(timeUntilNextHour)" # simple report
	47
	48	if ! myTTL="$(timeUntilNextHour)"; then yell "ERROR in if statement for myTTL:$myTTL"; exit 1; fi # Use of exit code to exit early if time <= 0.
	49	#==END sample code==