GTU OS Program - 13 Date Validator

13. Write a shell script to validate the entered date. (eg. Date format is : dd-mm-yyyy).

Complete code of the program

echo "Date validator"
#Initializing values of date, month and year
dd=0
mm=0
yy=0
 
#initializing no of days in a month
days=0
 
read -p "Enter day (dd) : " dd
read -p "Enter Month (mm) : " mm
read -p "Enter Year (yyyy) : " yy
 
#checking for invalid month
if [ $mm -le 0 -o $mm -gt 12 ]
then
        echo "$mm is invalid month. "
        exit 1
fi
 
#finding out no. of days in a month
case $mm in
        1 | 3 | 5 | 7 | 8 | 10 | 12)
                days=31
                ;;
        2)
                days=28
                ;;
        4 | 6 | 9 | 11)
                days=30
                ;;
        *)
                days=-1
                ;;
esac
 
#checking for leap year
if [ $mm -eq 2 ]
then
        a=`expr $yy % 4`
        b=`expr $yy % 100`
        c=`expr $yy % 400`
 
        if [ $a -eq 0 -a $b -ne 0 -o $c -eq 0 ]
        then
                days=29
        else
                break
        fi
fi
 
if [ $dd -le 0 -o $dd -gt $days ]
then
        echo "$dd day is invalid "
        exit 3
fi
 
#No error means date is valid
echo "$dd/$mm/$yy is a Valid Date"
 

Interpreting the date.sh file and executing it in terminal

tkanu025@hp:~/lab_solutions$ chmod +x date.sh
tkanu025@hp:~/lab_solutions$ ./date.sh

Output

Previous Program Next Program

gtu os lab manual,

os GTU Practical,

operating system Programs,

Operating system shellscript programs,

Gtu study material 3140705,

OS 3140702,

os practical list,

shell script programming,

gtu os practical,

shell script to validate the entered date. (eg. Date format is : dd-mm-yyyy).

os lab solution gtu