Issue with terraform apply command

While provisioning infrastructure in AWS using the Terraform tool, we have noticed that after provided input string “yes” we could not press “Enter” during the execution of the below command & it takes some weird character.

" terraform apply -var-file=cxxxxxxxxxxfilename.tfvars"

to overcome this issue i have use the below command.
But still i need to learn why it didnt work in the first place with above command.Please assist.

terraform apply -auto-approve -var-file=aws/dev.impcustomer/dev.impcustomers.tfvars