style(unitproc/):Shorten names of template prefix (bktemp -> bkt)

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

diff --git a/unitproc/bkt-timeUntilNextHour b/unitproc/bkt-timeUntilNextHour
new file mode 100644 (file)
index 0000000..6b56424
--- /dev/null
+++ b/unitproc/bkt-timeUntilNextHour
@@ -0,0 +1,53 @@
+#!/bin/bash
+# Desc: Template to report seconds until beginning of next hour
+
+#==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 $*"; }
+timeUntilNextHour(){
+    # Desc: Report seconds until next hour
+    # Version 1.0.1
+    # Output: stdout: integer seconds until next hour
+    # Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
+    # Usage: timeUntilNextHour
+    # Usage: if ! myTTL="$(timeUntilNextHour)"; then yell "ERROR in if statement"; exit 1; fi
+    
+    local returnState timeCurrent timeNextHour secondsUntilNextHour
+    timeCurrent="$(date --iso-8601=seconds)"; # Produce `date`-parsable current timestamp with resolution of 1 second.
+    timeNextHour="$(date -d "$timeCurrent next hour" --iso-8601=hours)"; # Produce `date`-parsable current time stamp with resolution of 1 second.
+    secondsUntilNextHour="$(( $(date +%s -d "$timeNextHour") - $(date +%s -d "$timeCurrent") ))"; # Calculate seconds until next hour (res. 1 second).
+    if [[ "$secondsUntilNextHour" -gt 0 ]]; then
+       returnState="true";
+    elif [[ "$secondsUntilNextHour" -eq 0 ]]; then
+       returnState="warning_zero";
+       yell "WARNING:Reported time until next hour exactly zero.";
+    elif [[ "$secondsUntilNextHour" -lt 0 ]]; then
+       returnState="warning_negative";
+       yell "WARNING:Reported time until next hour is negative.";
+    fi;
+
+    try echo "$secondsUntilNextHour"; # Report
+    
+    # Determine function return code
+    if [[ "$returnState" = "true" ]]; then
+       return 0;
+    elif [[ "$returnState" = "warning_zero" ]]; then
+       return 1;
+    elif [[ "$returnState" = "warning_negative" ]]; then
+       return 2;
+    fi;
+} # Report seconds until next hour
+#===END Declare local script functions===
+#==END Define script parameters==
+
+
+#==BEGIN sample code==
+try echo "Time until next hour (seconds):$(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==
+
+# Author: Steven Baltaktei Sandoval
+# License: GPLv3+