Question

• In this exercise, you will create a script called file_ops.sh that uses the various file operators
• The file_ops.sh script will
• Use one command line argument
• Use four IF THEN statement to compare the first command line argument
• Determine which file operators to use that produces the following output when the script run with the arguments shown

WARNING: In the IF THEN statements, to avoid syntax error messages, there must be a space before and after each bracket and also between each element within the brackets.

• Watching the video about File Test Operators may be helpful
• Look at the slide "File Operators"

• The first IF THEN statement has the form

If [ operator $1 ]

then

      echo "<message>"

fi

• Decide which operator to use that produces the message "… exists and is a file"

• The second IF THEN statement has the form

If [ operator $1 ]

then

      echo "<message>"

fi

• Decide which operator to use that produces the message "… exists"

• The third IF THEN statement has the form

If [ operator $1 ]

then

      echo "<message>"

fi

• Decide which operator to use that produces the message "… does not exist"

• The fourth IF THEN statement has the form

if [ ! operator $1 ]

then

      echo "<message>"

fi

• Decide which operator to use that produces the message "… exists and is a directory"

• Type the following commands. NOTE: You do not need to use 'gedit' to create your shell script. You can use 'vi' or 'nano' if you prefer
• Ignore anything highlighted in red as they are just comments

'clear' // Clear the screen

'cd ~/scripting_lab' // Change to the lab directory using tilde

'gedit file_ops.sh' // create the script using the editor of choice

'cat –n file_ops.sh' // show the script contents

// You will run file_ops.sh four times without changes to the script

'sh file_ops.sh /etc/passwd' // file exists

'sh file_ops.sh /etc/passwdd' // file does not exist

'sh file_ops.sh /etc' // directory

'sh file_ops.sh /etcc' // directory does not exist

'date'

• Using Snipping Tool, take a screenshot

Answer 1

Program:

arg=$1

if [ -f $arg ]
then
   echo "$arg exists and is a file"
fi
if [ -e $arg ]
then
   echo "$arg exists"
fi
if [ ! -e $arg ]
then
   echo "$arg does not exist"
fi
if [ -d $arg ]
then
   echo "$arg exists and is a directory"
fi

Screenshot: ( for reference )

Output:

Note: If you have any doubts please comment.

It will be great help If you like.