Shell Script To Encrypt Any Given Text File

In cryptography, encryption is the process of transforming information (referred to as plaintext) using an algorithm (called cipher) to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key.

Mcrypt is a simple crypting program, a replacement for the old unix crypt. When encrypting or decrypting a file, a new file is created with the extension .nc and mode 0600. The new file keeps the modification date of the original. The original file may be deleted by specifying the -u parameter. If no files are specified, the standard input is encrypted to the standard output.

Sample Shell Script Wrapper To Encrypt Any Text File

#!/bin/bash

# Write a shell script to encrypt any text file

file=$1

echo -n "Enter a file name : "

read file

if [ ! -f $file ]

then

        echo "$file not a file!"

        exit 1

fi

echo -n "Enter a Password : "

read password

# do encryption using UNIX crypt command

# this command will prompt for a password

crypt $password < $file > $file.cpy

echo  "$file.cpy created as encrypted file"