Script for checking whether a yubikey is present

yubikey-present.sh

#!/bin/bash
#
# A script to determine if a yubikey is present on the current host
#

RESULT=`2>&1 gpg --card-status`
CARD_ABSENT=`echo $RESULT | grep "OpenPGP card not available"`
if [ -z "${CARD_ABSENT}" ]
then
    SAVEIFS=$IFS   # Save current IFS (Internal Field Separator)
    IFS=$'\n'      # Change IFS to newline char
    lines=($RESULT)
    IFS=$SAVEIFS   # Restore original IFS
    SIGNATURE=`echo ${lines[17]} | awk -F":" '{print $2}'`
    if [ -z "${SIGNATURE}" ]
    then
        echo "false"
    else
        echo "true"
    fi
else
    echo "false"
fi