How do i modify this line to choose the first 15 characters?

computeridtmp="default"
LEN=$(echo ${#adcomputerid})

if [ $LEN -lt 15 ]; then
        echo "ComputerID "$adcomputerid " has 15 characters or less and is therefore suitable for AD-Binding. It is $adcomputerid"
        computeridtmp=$adcomputerid
else
        echo "ComputerID "$adcomputerid " has 16 or more characters and needs to be modified for AD-Binding."
    #echo "Removing any -"
        computeridtmp=${adcomputerid///}
        LEN=$(echo ${#computeridtmp})
        if [ $LEN -lt 15 ]; then
            echo "ComputerID "$computeridtmp" has now 15 characters or less and is therefore suitable for AD-Binding."
        else
            echo "Only using the last 15 characters of the Computer name to be able to bind to AD."
            computeridtmp=${computeridtmp}
        fi
        echo "Cropped Computername to "$computeridtmp

Never mind found it online.

Hi Everyone,

i found this script to join machines to the domain. I modified it to only use the first 15 characters of the Machine name.

#!/bin/sh

## Script to automate OD and AD Binding to the Servers
## Script written by Marc Horat, URZ Basel, 11.6.2010

# With the use of the following sources as inspiration:

# http://www.howtomac.co.uk/?p=247
#####################################
#Created by Ross Hamilton
#Clock restart / Remove existing settings
#Join to Open Directory and Active Directory
#
#####################################

# Bombich's AD-Bind Script:
# This script binds to AD and configures advanced options of the AD plugin
# As this scripts contains a password, be sure to take appropriate security
# precautions
# 
# A good way to run this script is to set it as a login hook on your master machine
# Because it only needs to be run once, the last thing this script does is to delete
# itself. If you have another login script that you typically run, include the 
# script on your master machine, and indicate its path in the "newLoginScript"
# variable.
#
# If running this as a one-time login hook to bind to AD after imaging,
# be sure to enable auto-login (for any local user) before creating your master image



############ Begin

# Host-specific parameters
# computerid should be set dynamically, this value must be machine-specific
# This value may be restricted to 19 characters! The only error you'll receive upon entering
# an invalid computer id is to the effect of not having appropriate privileges to perform the requested operation
#computerid=`/sbin/ifconfig en0 | awk '/ether/ { gsub(":", ""); print $2 }'` # MAC Address
#computerid=`hostname | sed 's/.unibas.ch//'`
#computerid=`/usr/sbin/scutil --get LocalHostName | cut -c 1-19` # Assure that this will produce unique names!
#computerid=`/usr/sbin/scutil --get LocalHostName`
computerid=`scutil --get ComputerName`
adcomputerid=`echo $computerid | tr [:lower:] [:upper:]`


# These variables probably don't need to be changed
nicAddress=`ifconfig en0 | grep ether | awk '{print $2}'`
check4OD=`dscl localhost -list /LDAPv3 | grep -n 1 | sed 's/1://' | sed 's/2://'`
check4ODacct=`dscl /LDAPv3/$check4OD -read Computers/"${computerid}" RealName | cut -c 11-`
check4AD=`dscl /Search -read / CSPSearchPath | grep /Active`
osversionlong=`sw_vers -productVersion`
osvers=${osversionlong:3:1}


#####################AD CONFIG#############################
# Standard parameters
domain="DOMAIN"            # fully qualified DNS name of Active Directory Domain
udn="USERNAME"            # username of a privileged network user
password="PASSWD"                    # password of a privileged network user
ou="OU=CONTAINER FOR MACHINE DROP"        # Distinguished name of container for the computer

# Advanced options AD Plugin
alldomains="disable"            # 'enable' or 'disable' automatic multi-domain authentication
localhome="disable"            # 'enable' or 'disable' force home directory to local drive
protocol="smb"                # 'afp' or 'smb' change how home is mounted from server
mobile="disable"            # 'enable' or 'disable' mobile account support for offline logon
mobileconfirm="disable"        # 'enable' or 'disable' warn the user that a mobile acct will be created
useuncpath="enable"            # 'enable' or 'disable' use AD SMBHome attribute to determine the home dir
user_shell="/bin/bash"        # e.g., /bin/bash or "none"
preferred="-nopreferred"    # Use the specified server for all Directory lookups and authentication
                            # (e.g. "-nopreferred" or "-preferred ad.server.edu")
admingroups="DOMAIN GROUPS FOR ADMIN PRIV"                # These comma-separated AD groups may administer the machine (e.g. "" or "APPLEmac admins")
packetsign="allow"            # allow | disable | require
packetencrypt="allow"        # allow | disable | require
passinterval="14"            # number of days
namespace="domain"            # forest | domain

# Login hook setting -- specify the path to a login hook that you want to run instead of this script
#newLoginHook="PATHTOLOGINHOOK"        # e.g., "/Library/Management/login.sh"


#####################END AD CONFIG#############################

#Time Sync

#Restart ntpdate
StartService ()
{
if [ "${TIMESYNC:=-YES-}" = "-YES-" ] && ! GetPID ntpd > /dev/null; then

CheckForNetwork

if [ -f /var/run/NetworkTime.StartupItem -o "${NETWORKUP}" = "-NO-" ]; then exit; fi
touch /var/run/NetworkTime.StartupItem

echo "Starting network time synchronization"

# Synchronize our clock to the network’s time,
# then fire off ntpd to keep the clock in sync.
ntpdate -bvs
ntpd -f /var/run/ntp.drift -p /var/run/ntpd.pid
fi
}

#List existing Directories
echo "This computer is bound to the following Active Directory Services:"
dscl /Search -read / CSPSearchPath | grep /Active

sleep 5
# Removing any existing directory bindings

# Removing any existing directory bindings

if [ "${check4ODacct}" == "${computerid}" ]; then
    echo "This machine already has a computer account on "${oddomain}"."
    if [ "$oldComputerGroup" != "" ]; then
        echo "Removing entry from group $oldComputerGroup"
        dscl -u "${odAdmin}" -P "${odPassword}" /LDAPv3/"$check4OD" -delete /ComputerGroups/"$oldComputerGroup" GroupMembership "${computerid}"
    fi
    echo "Removing Computer entry $computerid in OD"
    dscl -u "${odAdmin}" -P "${odPassword}" /LDAPv3/"$check4OD" -delete /Computers/"${computerid}"
fi
#A second time..
if [ "${check4ODacct}" == "${computerid}" ]; then
    echo "This machine already has a computer account on "${oddomain}"."
    if [ "$oldComputerGroup" != "" ]; then
        echo "Removing entry from group $oldComputerGroup"
        dscl -u "${odAdmin}" -P "${odPassword}" /LDAPv3/"$check4OD" -delete /ComputerGroups/"$oldComputerGroup" GroupMembership "${computerid}"
    fi
    echo "Removing Computer entry $computerid in OD"
    dscl -u "${odAdmin}" -P "${odPassword}" /LDAPv3/"$check4OD" -delete /Computers/"${computerid}"
fi


sleep 5

echo "Removing any existing AD-Binding to "$check4AD""
dsconfigad -f -r -u $udn -p "$password"
dscl /Search -delete / CSPSearchPath "$check4AD"
dscl /Search/Contacts -delete / CSPSearchPath "$check4AD"
dscl /Search -delete / CSPSearchPath "$check4AD"
sleep 5

echo "Killing DirectoryService"
killall DirectoryService

sleep 5

#############################################################
#AD
#############################################################

# Activate the AD plugin
defaults write /Library/Preferences/DirectoryService/DirectoryService "Active Directory" "Active"
plutil -convert xml1 /Library/Preferences/DirectoryService/DirectoryService.plist

computeridtmp="default"
LEN=$(echo ${#adcomputerid})

if [ $LEN -lt 15 ]; then
        echo "ComputerID "$adcomputerid " has 15 characters or less and is therefore suitable for AD-Binding. It is $adcomputerid"
        computeridtmp=$adcomputerid
else
        echo "ComputerID "$adcomputerid " has 16 or more characters and needs to be modified for AD-Binding."
    #echo "Removing any -"
        computeridtmp=${adcomputerid///}
        LEN=$(echo ${#computeridtmp})
        if [ $LEN -lt 15 ]; then
            echo "ComputerID "$computeridtmp" has now 15 characters or less and is therefore suitable for AD-Binding."
        else
            echo "Only using the last 15 characters of the Computer name to be able to bind to AD."
            computeridtmp=${computeridtmp:0:15}
        fi
        echo "Cropped Computername to "$computeridtmp 



fi

# Bind to AD
dsconfigad -f -a $computeridtmp -domain $domain -u $udn -p "$password" -ou "$ou"

# Configure advanced AD plugin options
if [ "$admingroups" = "" ]; then
    dsconfigad -nogroups
else
    dsconfigad -groups "$admingroups"
fi

dsconfigad -alldomains $alldomains -localhome $localhome -protocol $protocol 
    -mobile $mobile -mobileconfirm $mobileconfirm -useuncpath $useuncpath 
    -shell $user_shell $preferred -packetsign $packetsign -packetencrypt $packetencrypt 
    -passinterval $passinterval -namespace $namespace

sleep 10


# Add the OD & AD node to the search path
if [ "$alldomains" = "enable" ]; then
    csp="/Active Directory/All Domains"
else
    csp="/Active Directory/$domain"
fi

echo "Finished AD Binding."

echo "Now bound to AD Domain:"
dscl localhost -list "/Active Directory"
echo "With Search Path entries:"
dscl /Search -read / CSPSearchPath | grep /Active

echo "Restarting Directory Services."

# Restart DirectoryService (necessary to reload AD plugin activation settings)
killall DirectoryService

# Kill loginwindow to return to the login screen
killall loginwindow