3 # Desc: Template to display date and time. 
   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 
   9     # Desc: Timestamp without separators (YYYYmmddTHHMMSS+zzzz) 
  10     # Usage: dateTimeShort ([str date]) 
  12     # Input: arg1: 'date'-parsable timestamp string (optional) 
  13     # Output: stdout: timestamp (ISO-8601, no separators) 
  15     local argTime timeCurrent timeInput timeCurrentShort
 
  19     timeCurrent
="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second. 
  20     # Decide to parse current or supplied date 
  21     ## Check if time argument empty 
  22     if [[ -z "$argTime" ]]; then 
  23         ## T: Time argument empty, use current time 
  24         timeInput
="$timeCurrent"; 
  26         ## F: Time argument exists, validate time 
  27         if date --date="$argTime" 1>/dev
/null 
2>&1; then 
  28             ### T: Time argument is valid; use it 
  31             ### F: Time argument not valid; exit 
  32             yell 
"ERROR:Invalid time argument supplied. Exiting."; exit 1; 
  35     # Construct and deliver separator-les date string 
  36     timeCurrentShort
="$(date -d "$timeInput" +%Y%m%dT%H%M%S%z)"; 
  37     echo "$timeCurrentShort"; 
  38 } # Get YYYYmmddTHHMMSS±zzzz 
  40 #==BEGIN sample code== 
  41 echo "The current day and time is :$(dateTimeShort)"; 
  42 echo "Contact lost with STS-107 on:$(dateTimeShort "2003-02-01T08:59:15-05:00")"; 
  43 echo "Bitcoin started on          :$(dateTimeShort "@
1231006505")"; 
  44 testDate
="2020-07-07T02:30:11,690097074+00:00"; 
  45 echo "This string was generated using 'date --iso-8601=ns':$testDate"; 
  46 echo "Using dateTimeShort, it appears as:$(dateTimeShort "$testDate")"; 
  49 # Author: Steven Baltakatei Sandoval