Shell Programming and Scripting

cat maillist.txt$1          $2            $3
login1    password1 @mail1
login2    password2 @mail2
login3    password3 @mail3

cat letter.txt
Hello,
Here is your login : $1 and your password : $2
cordially

vi my_script.sh#!/bin/bash
cat maillist.txt|while read user
do
cat letter.txt|mail -s "Your subject" $3
done
exit

$ cat letter.txt
Hello,
Here is your login : _USERNAME_ and your password : _PASSWORD_
cordially
$

$ cat maillist.txt
unixforum password-U unixforum@localhost
root password-R root@localhost
$

$ cat my_script.sh
#!/bin/bash

cat maillist.txt | while read -r line
do
        username=`echo $line | awk '{print $1}'`
        password=`echo $line | awk '{print $2}'`
        email=`echo $line | awk '{print $3}'`

        cat letter.txt | sed -e s/_USERNAME_/$username/g -e s/_PASSWORD_/$password/g | mail -s "Your subject" $email
done
$

$ whoami
unixforum
$ ./my_script.sh
$ mail
"/var/mail/unixforum": 1 message 1 new
>N   1 unixforum@localhost Sat Feb 11 10:28  17/719   Your subject
? 1
<e-mail headers appear here, redacted>

Hello,
Here is your login : unixforum and your password : password-U
cordially
? d 1
? q
Held 0 messages in /var/mail/unixforum
$

while read username password email
  do sed "s/\$1/$username/; s/\$2/$password/;" file1 | mail -s "Your subject" $email
  done < file2