[SOLVED] IF Statement that compares today's date with a date entered

Icewolf0927 · 08-13-2011, 05:31 PM

Hi
I am trying to write a simple IF statement in VI that would look at the systems date and compare it to a date that someone has entered in to the terminal and depending if the date matches it would display a message on the screen. I have gotten it to prompt for the date on the terminal but it doesn't matter what date I put in it just give the ELSE prompt. I am not sure what I am doing wrong.

Code:

echo "Enter Date"
read option
if [ "$option" = date +"%m-%d-%Y"]; then
        echo "Homework is due."
else
        echo "Do your homework!"
fi

Here is a sample of the output. I pulled the date to see what it looks like so I can make sure the format is the same.

Code:

[Icewolf@Crazy ~]$ date +"%m-%d-%Y"
08-13-2011
[Icewolf@Crazy ~]$ ./lab5if
Enter Date08-13-2011
./lab5if: line 5: [: missing `]'
Do your homework!

Thanks
Andy

roger_heslop · 08-13-2011, 06:34 PM

Whenever you want to compare a value to the result of a command, try surrounding the command with $( ). The below will work:

Code:

echo "Enter Date"
read option
if [ "$option" = $( date +"%m-%d-%Y" ) ]; then
        echo "Homework is due."
else
        echo "Do your homework!"
fi

Icewolf0927 · 08-13-2011, 07:00 PM

Thanks again. That worked.

tonyfreeman · 08-13-2011, 08:41 PM

Here's mine with a small difference.

I always use the double = sign (==) to test for equivalency. Most languages will assign values when using only one = sign ... the == does not assign a value but tests for a value.

Code:

#!/bin/bash

read -p "Enter Date: " option

if [[ $option == $(date +"%m-%d-%Y") ]]
then
        echo "Homework is due"
else
        echo "Do your homework!"
fi

roger_heslop · 08-13-2011, 10:21 PM

Well played tonyfreeman.