3 # Desc: Template to display date
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 $*"; } #o
9 # Desc: Date without separators (YYYYmmdd)
10 # Usage: dateShort ([str date])
12 # Input: arg1: 'date'-parsable timestamp string (optional)
13 # Output: stdout: date (ISO-8601, no separators)
15 local TIME_CURRENT DATE_CURRENT_SHORT
19 TIME_CURRENT
="$(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";
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";
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 DATE_CURRENT_SHORT
="$(date -d "$TIME_INPUT" +%Y%m%d)"; # Produce separator-less current date with resolution 1 day.
37 echo "$DATE_CURRENT_SHORT";
40 #==BEGIN sample code==
41 echo "The current day is :$(dateShort)";
42 echo "Contact lost with STS-107 on:$(dateShort "2003-02-01T08:59:15-05:00")";
43 echo "Bitcoin started on :$(dateShort "@
1231006505")";
46 # Author: Steven Baltakatei Sandoval