From: Robert Klemme <shortcutter@...>
Date: 2010-06-02T00:44:12+09:00
Subject: Re: looping through array elements (noob question)

2010/6/1 Nate St.germain <n8@adullmoment.com>:
> please bear with me on this. i'm blundering my way through learning
> ruby.
>
> i have a script intended to run on os x to restore local admin rights to
> users who've had the rights removed by another script. it's sort of a
> fallback measure. i'm using this as an opportunity to learn ruby in the
> process.
>
> the newest version of the removal script (bash) will add a plain text
> file in /Library/Receipts containing the account short names on which it
> just operated. i want the restore script to be flexible enough to either
> read the list from the file if it exists or get the users from scratch
> using the "/usr/sbin/jamf listUser" command (part of the Casper admin
> suite), which outputs xml, unfortunately. at some point, i'll probably
> switch to another method to avoid having to resort to regex matches on
> the xml tags.
>
> regardless, the issue is the getUsers() method works fine on its own but
> then give me the following output when run from the script (below):
>
> sam
> norton
> mary
> Restoring admin rights for     <name>sam</name>
> Restoring admin rights for     <name>norton</name>
> Restoring admin rights for     <name>mary</name>
>
> so in the actual script, the names are returned once correctly, then
> again with the xml tags and tabs intact. i'm not sure what i'm missing
> here.
>
> it's probably something obvious, and i'm sure this script can be written
> more concisely. i appreciate any pointers you have. note, the actual
> admin rights granting lines are commented below for testing.
>
>
> === script ===
>
> #!/usr/bin/env ruby
> # restore rights to local users who've recently had them removed.
> # 5/25/10, nate@tsp
> # 6/1/10, updated
>
> # set system variable
> # chops out the second digit in the version number, which is the only
> differentiating factor here
> def getos()
>  system=`/usr/bin/sw_vers
> -productVersion`.chomp.split(".").slice(1).to_i
>  if system==4 then
>    return "tiger"
>  else
>      return "leo"
>  end
> end
>
> # cheating by using the jamf binary.
> def getUsers()
>  userlist=`/usr/sbin/jamf listUsers`.to_a
>  users=userlist.grep /\<name/
>  users.each { |user| puts user.split(/<[^>]*[^>]*>/)[1] }

The line above produces the output of the short names - and then it
returns "users" *unmodified*.  This means that the array returned from
getUsers() still has all the XML tags in there.

You can replace that line with:

users.map { |user| user.split(/<[^>]*[^>]*>/)[1] }

Or, with an alternative approach

def get_users
  users = []
  `/usr/sbin/jamf listUsers`.scan(/<name>(.*?)</name>/) { users << $1 }
  users
end

Or even use an XML tool (e.g. REXML) to extract values of tags if the
input is valid XML.

Note: conventionally we use CamelCase only for ClassNames and not for
method_names.

> end
>
> # method to read admins from a text file from a removal run
> # this may not be necessary if included in the restoreAdmin methods
> def readAdmins()
>  receipt=File.open('/Library/Receipts/org.company.removedadmins', 'r')
>  return receipt.readlines
> end
>
> # use dseditgroup for 10.[5-6] clients
> def restoreAdmin5()
>  if File.exist?('/Library/Receipts/org.company.removedadmins') then
>    users=readAdmins
>    users.each do |u|
>    puts "Restoring admin rights for #{u}"
>  #  %x(/usr/sbin/dseditgroup -o edit -a  #{u} -t user admin)
>    end
>  else
>    users=getUsers
>    users.each do |u|
>    puts "Restoring admin rights for #{u}"
>  #  %x(/usr/sbin/dseditgroup -o edit -a  #{u} -t user admin)
>    end
>  end
> end
>
> # use nicl for 10.4 clients
> def restoreAdmin4()
>  if File.exist?('/Library/Receipts/org.company.removedadmins') then
>    users=readAdmins
>    users.each do |u|
>      puts "Restoring admin rights for #{u}"
>  #    %x(nicl -raw /var/db/netinfo/local.nidb -append /groups/admin
> users #{u})
>  end
>  else
>    users=getUsers
>    users.each do |u|
>    puts "Restoring admin rights for #{u}"
>  #  %x(nicl -raw /var/db/netinfo/local.nidb -append /groups/admin users
> #{u})
>    end
>  end
> end
>
> # test the os with the getos() method and proceed accordingly based on
> platform
> result = case getos()
>  when "tiger" then
>    restoreAdmin4
>  when "leo" then
>    restoreAdmin5
>  else puts "no version specified. stopping..."
>  end

Kind regards

robert


-- 
remember.guy do |as, often| as.you_can - without end
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