# Looping through array elements (noob question)

**URL:** <https://www.ruby-forum.com/t/looping-through-array-elements-noob-question/189484>\
**Category:** Ruby\
**Created:** [June 1, 2010, 5:20pm UTC](https://www.ruby-forum.com/t/looping-through-array-elements-noob-question/189484 "2010-06-01T17:20:19Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![diemorph](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/76d3ee/32.png) [@diemorph](https://www.ruby-forum.com/u/diemorph)\
**Post date:** [June 1, 2010, 5:20pm UTC](https://www.ruby-forum.com/t/looping-through-array-elements-noob-question/189484/1 "2010-06-01T17:20:19Z")

</div>

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 sam  
Restoring admin rights for norton  
Restoring admin rights for mary

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] }  
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

---

<div class="post-metadata">

**Author:** ![diemorph](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/76d3ee/32.png) [@diemorph](https://www.ruby-forum.com/u/diemorph)\
**Post date:** [June 1, 2010, 5:46pm UTC](https://www.ruby-forum.com/t/looping-through-array-elements-noob-question/189484/2 "2010-06-01T17:46:46Z")

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2010/6/1 Nate St.germain [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> just operated. i want the restore script to be flexible enough to either  
> norton  
> more concisely. i appreciate any pointers you have. note, the actual
> 
> # set system variable
> 
> 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(/(.\*?)/) { 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.

> def restoreAdmin5()
> 
> # %x(/usr/sbin/dseditgroup -o edit -a #{u} -t user admin)
> 
> # %x(nicl -raw /var/db/netinfo/local.nidb -append /groups/admin
> 
> 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

---

<div class="post-metadata">

**Author:** ![diemorph](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/76d3ee/32.png) [@diemorph](https://www.ruby-forum.com/u/diemorph)\
**Post date:** [June 1, 2010, 5:49pm UTC](https://www.ruby-forum.com/t/looping-through-array-elements-noob-question/189484/3 "2010-06-01T17:49:17Z")

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Robert K. wrote:

> Note: conventionally we use CamelCase only for ClassNames and not for  
> method\_names.
> 
> Kind regards
> 
> robert

thanks, robert. i’ll give that a shot. the camel case is a holdover from  
way back. i appreciate the tips.