Question in bash script.

Shell Programming and Scripting
1

Hi All,
I need an assistance with the issue below.
I wrote big script in "bash" that automatically install an LDAP on Clients.
I'd be happy to know in order to avoid duplication of entries in files,
How i can define into the script, if the specific expressions already exist in the file, do not add them again.
For example i take the following section from the script :

echo "admin ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
echo "%linuxadmin ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers

How i define in the script , only if the value are already exists in the file , do not add it again.
i have the same thing with sections that write expressions to more files.
The thing is that i sometimes i need to run the script more than once on the same server,and as a result of that it created duplicate values in multiple files.
Thank you guys,

Aviel.

2

If you just want to avoid duplicating the string you would add with your script...

egrep "$value" $file || echo "$value" >> $file
3

Skrynesaver,
can you be more specific,

At the section :

#Add permission to sysadmin
echo "admin ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
echo "%linuxadmin ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers

Where i should put the expressions before or after this section ,
And how do you write the expression you gave me that would be suitable for the pare here,

Thanks ,

Aviel.

4

It's just checking the return value of grep for the existence of the record you wish to add in the file...

value='admin ALL=(ALL) NOPASSWD: ALL'
file=/etc/sudoers
grep "$value" $file || echo "$value" >> $file
value="%linuxadmin ALL=(ALL) NOPASSWD: ALL"
grep "$value" $file || echo "$value" >> $file
5

I Add it to the script, but it didnt work.
The Duplicate value still getting added to /etc/sudoers

6

Did you replace the 2 lines echoing the value to the file without checks?

7

Added to the script :

value='admin ALL=(ALL) NOPASSWD: ALL'
file=/etc/sudoers
grep "$value" $file || echo "$value" >> $file
value="%linuxadmin ALL=(ALL) NOPASSWD: ALL"
grep "$value" $file || echo "$value" >> $file

deleted from script : 

#Provide to system administrators accounts root privileges
echo "admin        ALL=(ALL)       NOPASSWD: ALL"   >> /etc/sudoers echo "%linuxadmin  ALL=(ALL)       NOPASSWD: ALL" >> /etc/sudoers
8

strange, which flavour of grep are you using...the brackets may be being interpreted as grouping parenthesis rather than strings by grep... in which case you would have to escape them.