unitproc/bktemp-dateShort

   1 #!/bin/bash
   2
   3 # Desc: Template to display date
   4
   5 yell() { echo "$0: $*" >&2; }      #o Yell, Die, Try Three-Fingered Claw technique
   6 die() { yell "$*"; exit 111; }     #o Ref/Attrib: https://stackoverflow.com/a/25515370
   7 try() { "$@" || die "cannot $*"; } #o
   8 dateShort(){
   9     # Desc: Date without separators (YYYYmmdd)
  10     # Usage: dateShort ([str date])
  11     # Version: 1.1.0
  12     # Input: arg1: 'date'-parsable timestamp string (optional)
  13     # Output: stdout: date (ISO-8601, no separators)
  14     # Depends: yell
  15     local TIME_CURRENT DATE_CURRENT_SHORT
  16
  17     argTime="$1";
  18     # Get Current Time
  19     TIME_CURRENT="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
  20     # Decide to parse current or supplied date
  21     ## Check if time argument empty
  22     if [[ -z "$argTime" ]]; then
  23         ## T: Time argument empty, use current time
  24         TIME_INPUT="$TIME_CURRENT";
  25     else
  26         ## F: Time argument exists, validate time
  27         if date --date="$argTime" 1>/dev/null 2>&1; then
  28             ### T: Time argument is valid; use it
  29             TIME_INPUT="$argTime";
  30         else
  31             ### F: Time argument not valid; exit
  32             yell "ERROR:Invalid time argument supplied. Exiting."; exit 1;
  33         fi
  34     fi
  35     # Construct and deliver separator-les date string
  36     DATE_CURRENT_SHORT="$(date -d "$TIME_INPUT" +%Y%m%d)"; # Produce separator-less current date with resolution 1 day.
  37     echo "$DATE_CURRENT_SHORT";
  38 } # Get YYYYmmdd
  39
  40 #==BEGIN sample code==
  41 echo "The current day is          :$(dateShort)";
  42 echo "Contact lost with STS-107 on:$(dateShort "2003-02-01T08:59:15-05:00")";
  43 echo "Bitcoin started on          :$(dateShort "@1231006505")";
  44 #==END sample code==
  45
  46 # Author: Steven Baltakatei Sandoval
  47 # License: GPLv3+