The Shell Game

Yeah, I’m a BOINC junky. I’ll admit it. I’m finding that scripting is exceedingly useful for stuff I used to pull out pencil and paper for. I’m not programmer. Heck, I’m not much of a scripter. I’ve written exactly five scripts and only three of them actually work the way I want them to. But hey, a gal has to start somewhere.

One of the questions I frequently ask myself is how long will it take me to reach X number of credits in a certain project given my current RAC (recent average credit). There are variations on the question, but they all boil down to the same basic formula. You take your goal and subtract the number of credits you currently have and then divide by your RAC. Or to put it another way, (goal-credits)/rac. Easy.

Now it may seem sort of dumb to write a script to figure this out. I mean, it’s just as quick to pull out my calculator or do it in my head. OK, maybe it’s faster than doing it in my head. But it does give me practice in scripting. And that’s the important thing.

So here you go. If you have suggestions for improvements please leave them in the comments. Enjoy!

Oh yes, and sorry about all the extra comment marks. My HTML is even worse than my scripting. Not having any blank lines was the only way I could get everything to show up in one code block and using pre tags cut off the far right side of the text.

#
#!/bin/bash
#
# Use to predict the number of days until
# a certain number of BOINC credits will be reached.
#
# See http://boinc.berkeley.edu/ for more information on BOINC.
#
# This script makes use of the calculator feature in Bash.
# Because Bash is only able to do integer math,
# all values must be rounded to the nearest whole number.
#
# Kathryn Marks
# <kathryn.boinc@gmail.com>
#
# Created: January 3, 2008
# Last Modified: January 3, 2008
#
#
# Define our variables
# CREDITS is the current number of credits for a project
# RAC is the recent average credit for a project
# GOAL is the number of credits you want
# DAYS is the number of days until $GOAL is reached
#
# Start by initializing the variables
#
CREDITS=0
RAC=0
GOAL=0
DAYS=0
#
# Remind the user to use only integer values for CREDITS, RAC and GOAL
#
echo " "
echo "It's very important that you only put in whole numbers."
echo " "
#
# Have the user input values for CREDIT, RAC and GOAL
#
echo -n "Enter the number of credits you currently have > "
read CREDITS
#
echo -n "Enter your RAC > "
read RAC
#
echo -n "Enter your credit goal > "
read GOAL
#
# Now calculate the value of DAYS
#
DAYS=$(((GOAL - CREDITS) / RAC))
#
# Display the value of DAYS in user friendly way
#
echo "It will be approximately $DAYS day(s) until you reach your goal of $GOAL credits."
#
# EOF