Calculating age in days and month in a bash script

jachba · 06-22-2006, 05:59 PM

I could use some help. I'm working in a bash script and need help with calculating an individual's age in years and months. Calculating the years was simple but months are proving to be a challenge. Thanks in advance for anyone who can help.

archtoad6 · 06-23-2006, 08:13 AM

What does it look like so far? (Hint: use [code] tags).

Also, what will the input look like? Your choice of input format is very important.

How do you define a month? This is not a trivial Q, ask any banker or anyone else calculating interest & principal.

jachba · 06-23-2006, 12:01 PM

Here's what I have in the section I'm working on. I know that the if statement doesn't work properly (it calculates correctly but still expresses the month category as a negative number) but I'm stuck on how to fix it.

agey=$(($yearnow-$year))
agem=$(($monthnow-$month))

if [ $agem < 0 ]
then
agem=$(($monthnow-$month+12))

else
agem=$(($monthnow-$month))
fi

archtoad6 · 06-23-2006, 12:15 PM

Please re-post using the [code] tags -- code doesn't look right displayed as text.

Also answer the rest of the Q's -- I can't do a thing for you if I don't know what your data looks like or what your variables hold.

homey · 06-23-2006, 12:42 PM

I think your biggest problem came from this part ....

Code:

if [ $agem < 0 ] instead of this 
if [ $agem -lt 0 ]

Code:

#!/bin/bash

read -p "Enter your birth year.  Example: 1900 : " year
read -p "Enter your birht month. Example: 06 " month

yearnow=$(date '+%Y')
monthnow=$(date '+%m')

agey=$(($yearnow-$year))
agem=$(($monthnow-$month))

if [ $agem -lt 0 ] ; then
   agem=$(($monthnow-$month+12))
else
   agem=$(($monthnow-$month))
fi
echo "You are $agey years and $agem months old!"

jachba · 06-23-2006, 01:37 PM

Thanks, homey. It works fine now.