Bash Scripting: Checking Directory and File

#!/bin/bash
#
location=$HOME
filen="sentinel"
#
if [ -e $location ]
then
        echo "Ok on the $location directory"
        echo "Now checking on the file, $filen"
        #
        if [ -e $location/$filen ]
        then
                echo "OK on the filename"
                echo "Updating Current Date..."
                date >> $location/$filen

        #
        else
                echo "File does not exist"
                echo "Nothing to update"
        fi

#
else
        echo "The $location directory does not exist"
        echo "Nothing to update"
fi

Bash Script: Check if user is on system

#!/bin/bash
function usersys {
if grep $USERN /etc/passwd
then
        echo "$USERN is in system."
        exit 0
#
else
        echo "$USERN is not in system."
        exit 0

fi

}
#

function usr {
read -p "Enter username:" USERN

if test $USERN
then
        echo "Username: $USERN"
        usersys
#
else
        echo "You did not enter a username. Enter Username"
        usr
fi
}

usr

LX0-104: Chapters Reviews and Exercises

LX0-104

Chapters Reviews    Exercises

2               57              2-7, 2-8

4               114             x

5               157             x

7                232           7-1

9                334           9-1, 9-2

13              492            13-2

14              529             14-2

15              579             15-1, 15-2

16              630             16-1, 16-2, 16-3

17              689              17-1, 17-2, 17-3

18              734              18-1, 18-2, 18-3, 18-4