Shell Script for the #100DaysToOffload Challenge

I am getting quite close to my 1-year mark since I started the #100DaysToOffload challenge. Some quick mafs tell me that I can’t skip that many days if I want to make it to 100 blog posts by the end of the 365 days.

I wrote a script that takes the date when I made my first #100DaysToOffload blog post and the number of blog posts I have written through for challenge so far. The script then calculates some numbers to… motivate.

Here’s the script:

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#!/bin/bash

STARTED_ON=$1
POSTS_MADE=$2

STARTED_ON=`date -d "$STARTED_ON" +'%Y-%m-%d'`

ENDS_ON=`date -d "$STARTED_ON+365 days" +'%Y-%m-%d'`

DAYS_LEFT=`expr '(' $(date -d $ENDS_ON +'%s') - $(date +'%s') + 86399 ')' / 86400`
POSTS_LEFT=`expr '(' 100 - $POSTS_MADE ')'`

RATE=`echo "scale=2; $DAYS_LEFT / $POSTS_LEFT" | bc`

BOLD=`tput bold`
PLAIN=`tput sgr0`

echo "${BOLD}#100DaysToOffload Challenge${PLAIN}"
echo 'Started On:' $STARTED_ON
echo 'Posts Made:' $POSTS_MADE
echo
echo "You have ${BOLD}$DAYS_LEFT days remaining${PLAIN} to write ${BOLD}$POSTS_LEFT blog posts${PLAIN}."
echo "You need to make a new blog post ${BOLD}every $RATE days${PLAIN}."

Some interesting things that I learned while preparing this script include:

• The use of date -d to work on a specific date. For example date -d 2023-09-03 +%s will print the given date as seconds since epoch.
• The use of expr for some of the maths.
• The use of bc for floating-point maths (which expr doesn’t support).
• The use of tput to get the right sequences for formatting texts (that is how we are making some of the output text bold).

This post is 35th of my #100DaysToOffload challenge. Want to get involved? Find out more at 100daystooffload.com.