| 1 | #!/bin/bash |
| 2 | # Desc: Template to display date |
| 3 | |
| 4 | yell() { echo "$0: $*" >&2; } #o Yell, Die, Try Three-Fingered Claw technique |
| 5 | die() { yell "$*"; exit 111; } #o Ref/Attrib: https://stackoverflow.com/a/25515370 |
| 6 | try() { "$@" || die "cannot $*"; } #o |
| 7 | dateShort(){ |
| 8 | # Desc: Date without separators (YYYYmmdd) |
| 9 | # Usage: dateShort ([str date]) |
| 10 | # Version: 1.1.2 |
| 11 | # Input: arg1: 'date'-parsable timestamp string (optional) |
| 12 | # Output: stdout: date (ISO-8601, no separators) |
| 13 | # Depends: bash 5.0.3, date 8.30, yell() |
| 14 | local argTime timeCurrent timeInput dateCurrentShort |
| 15 | |
| 16 | argTime="$1"; |
| 17 | # Get Current Time |
| 18 | timeCurrent="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second. |
| 19 | # Decide to parse current or supplied date |
| 20 | ## Check if time argument empty |
| 21 | if [[ -z "$argTime" ]]; then |
| 22 | ## T: Time argument empty, use current time |
| 23 | timeInput="$timeCurrent"; |
| 24 | else |
| 25 | ## F: Time argument exists, validate time |
| 26 | if date --date="$argTime" 1>/dev/null 2>&1; then |
| 27 | ### T: Time argument is valid; use it |
| 28 | timeInput="$argTime"; |
| 29 | else |
| 30 | ### F: Time argument not valid; exit |
| 31 | yell "ERROR:Invalid time argument supplied. Exiting."; exit 1; |
| 32 | fi; |
| 33 | fi; |
| 34 | # Construct and deliver separator-les date string |
| 35 | dateCurrentShort="$(date -d "$timeInput" +%Y%m%d)"; # Produce separator-less current date with resolution 1 day. |
| 36 | echo "$dateCurrentShort"; |
| 37 | } # Get YYYYmmdd |
| 38 | |
| 39 | #==BEGIN sample code== |
| 40 | echo "The current day is :$(dateShort)"; |
| 41 | echo "Contact lost with STS-107 on:$(dateShort "2003-02-01T08:59:15-05:00")"; |
| 42 | echo "Bitcoin started on :$(dateShort "@1231006505")"; |
| 43 | #==END sample code== |
| 44 | |
| 45 | # Author: Steven Baltakatei Sandoval |
| 46 | # License: GPLv3+ |