Question

I am working with cal for a homework assignment and i am stuck on one point.

It is unlikely that anyone is really interested in getting a gregorian
calendar for a year in the first century, a time when the gregorian
calendar didn’t even exist. Use the “windowing” strategy to allow your
new cal to handle years that are not the full 4 digit year. If the
year is in the range of 0 <= year <= 50, assume the year is really
2000-2050. If the year is in the range 51 <= year <= 99, assume the
year is really 1951-1999.

file named improvedcal.sh
call the shell with sh improvedcal.sh 1 2011 for example
code

case $# in 

# rando stuff

*) m=$1; y=$2 ; # 2 ags: month and year
if ((y >= 0 && y <= 50)); then  
y+=2000
elif ((y >= 51 && y <= 99)); then
y+=1900
fi;;
esac

case $m in
jan*|Jan*) m=1 ;;
feb*|Feb*) m=2 ;;
mar*|Mar*) m=3 ;;
apr*|Apr*) m=4 ;;
may*|May*) m=5 ;;
jun*|Jun*) m=6 ;;
jul*|Jul*) m=7 ;;
aug*|Aug*) m=8 ;;
sep*|Sep*) m=9 ;;
oct*|Oct*) m=10 ;;
nov*|Nov*) m=11 ;;
dec*|Dec*) m=12 ;;
[1-9]|10|11|12) ;; # numeric month
0[1-9]|010|011|012) ;; # numeric month
# *) y=$m; m="" ;; # plain year
esac

/usr/bin/cal $m $y # run cal with new inputs

But this is not working for some reason does anyone have any pointers for me?
It just skips right over this part for some reason.

Answer 1

Try running your script with bash -xv, it will help you understand what is happening.

Read also Bash programming intro