Check if file exist inside tar file using tar and grep command

Question

I have a script that check if a file exist inside a tar file but something's wrong because it always go to the 'else' part of the script. I am pretty sure that it shouldn't be that way.

The date is in "Mon dd" format (Jan 11).

echo "enter date: \c"
read date
tarfile=`tar -tvf tarfile.tar | grep some_file | grep "$date"`

if [ -f "$tarfile" ]; then
   echo "yes"
else
   echo "no"
fi

Thanks.

Solution

Because some_file is inside the tarfile.tar file but your if is checking for it to be on the file system.

You can alter it like this

if tar –tf tarfile.tar some_file >/dev/null 2>&1; then
    echo "tarfile.tar contains some_file"
fi