Script that return the name of the current ssh user

whoami.sh

#!/usr/bin/env bash

if [ -z "$SSH_TTY" ]; then
    exit 3
fi

LOGINTIME=`last -RF ${SSH_TTY:5} | head -n1 | awk '{print $6}'`

MATCH=`echo $USER $SSH_CLIENT | awk '{print " Accepted publickey for " $1 " from " $2 " port " $3 " ssh2"}'`

FINGERPRINT=`grep $LOGINTIME /var/log/auth.log | grep -v " debug1: " | grep -B1 "$MATCH" | head -n1 | awk '{print $NF}'`

if [ -z "$FINGERPRINT" ]; then
    exit 2;
fi

KEYS=/tmp/keys.$$
KF=/tmp/sshkey.$$

cat ~/.ssh/authorized_keys ~/.ssh/authorized_keys2 > $KEYS 2>/dev/null

while read -r line; do
    echo $line > $KF
    F=`ssh-keygen -l -f $KF | awk '{print $2}'`
    rm -f $KF
    if [ "$FINGERPRINT" = "$F" ]; then
  rm -f $KEYS
        U=`echo $line | awk '{print $NF}'`
        echo $U
        exit 0
    fi
done < $KEYS
rm -f $KEYS
exit 1;