Bash script to fill in a template

I suspect you are looking for something quite simple like a file my_script that contains:

cat <<<XXX
dn: uid=$1,ou=home,dc=chan,dc=com

objectClass: organizationalPerson

objectClass: person

objectClass: inetOrgPerson

objectClass: top

cn: $2

sn: $3

userid: $1

userPassword:
XXX

To use the above, simply run:

sh my_script fred 100 200

which will output to stdout (and can be redirected to a file).

Does there actually need to be a template file?

#!/bin/bash

echo "dn: uid=$1,ou=home,dc=chan,dc=com" > $4
echo "objectClass: organizationalPerson" >> $4
echo "objectClass: person" >> $4
echo "objectClass: inetOrgPerson" >> $4 
echo "objectClass: top" >> $4
echo "cn: $2" >> $4
echo "sn: $3" >> $4
echo "userid: $1" >> $4
echo "userPassword:" >> $4

You would run ./SCRIPTNAME Value1 Value2 Value3 OutputFileName

otherwise

You script would be:

#!/bin/bash

var1=$1
var2=$2
var3=$3
file=$4

cat TemplateFile > $file

sed -i "s/1/$var1/g" $file
sed -i "s/2/$var2/g" $file
sed -i "s/3/$var3/g" $file

and your template file would be

dn: uid=1,ou=home,dc=chan,dc=com 
objectClass: organizationalPerson
objectClass: person
objectClass: inetOrgPerson
objectClass: top
cn: 2
sn: 3
userid: 1
userPassword: