93 List NetInfo Users

#93 List NetInfo Users

To begin seeing how to work with NetInfo, here's a straightforward script that allows you to easily interface with the NetInfo database through the nireport utility.

The Code

 #!/bin/sh # listmacusers - Simple script to list users in the Mac OS X NetInfo database. #   Note that Mac OS X also has an /etc/passwd file, but that's #   used only during the initial stages of boot time and for #   recovery bootups. Otherwise, all data is in the NetInfo db. fields="" while getopts "Aahnprsu" opt ; do   case $opt in     A ) fields="uid passwd name realname home shell"    ;;     a ) fields="uid name realname home shell"           ;;     h ) fields="$fields home"                           ;;     n ) fields="$fields name"                           ;;     p ) fields="$fields passwd"                         ;;     r ) fields="$fields realname"                       ;;     s ) fields="$fields shell"                          ;;     u ) fields="$fields uid"                            ;;     ? ) cat << EOF >&2 Usage: 
 #!/bin/sh # listmacusers - Simple script to list users in the Mac OS X NetInfo database. # Note that Mac OS X also has an /etc/passwd file, but that's # used only during the initial stages of boot time and for # recovery bootups. Otherwise, all data is in the NetInfo db. fields="" while getopts "Aahnprsu" opt ; do case $opt in A ) fields="uid passwd name realname home shell" ;; a ) fields="uid name realname home shell" ;; h ) fields="$fields home" ;; n ) fields="$fields name " ;; p ) fields="$fields passwd" ;; r ) fields="$fields realname" ;; s ) fields="$fields shell" ;; u ) fields="$fields uid" ;; ? ) cat << EOF >&2 Usage: $0 [Aahnprsu] Where: -A output all known NetInfo user fields -a output only the interesting user fields -h show home directories of accounts -n show account names -p passwd (encrypted) -r show realname/ fullname values -s show login shell -u uid EOF exit 1 esac done exec nireport . /users ${fields:=uid name realname home shell} 
 [Aahnprsu] Where:    -A    output all known NetInfo user fields    -a    output only the interesting user fields    -h    show home directories of accounts    -n    show account names    -p    passwd (encrypted)    -r    show realname/fullname values    -s    show login shell    -u    uid EOF exit 1   esac done exec nireport . /users ${fields:=uid name realname home shell} 

How It Works

Almost this entire script is involved in building the variable fields , which starts out blank. The nireport utility allows you to specify the names of the fields you'd like to see, and so, for example, if the user specifies -a for all interesting fields, nireport actually is fed

 fields="uid name realname home shell" 

This is a clear, straightforward script that should be quite easily understood .

Running the Script

The listmacusers script accepts quite a few different command arguments, as shown in the usage message. You can specify exact fields and field order by using hnprsu , or you can list all fields except the encrypted password field with -a or force everything to be listed with -A . Without any arguments, the default behavior is to show all interesting user fields ( -a ).

The Results

First off, let's specify that we want to see the user ID, login name, real name, and login shell for every account in the NetInfo database:

 $  listmacusers -u -n -r -s  -2      nobody  Unprivileged User       /dev/null 0       root    System Administrator    /bin/tcsh 1       daemon  System Services /dev/null 99      unknown Unknown User    /dev/null 25      smmsp   Sendmail User   /dev/null 70      www     World Wide Web Server   /dev/null 74      mysql   MySQL Server    /dev/null 75      sshd    sshd Privilege separation       /dev/null 505     test3   Mr. Test Three  /bin/tcsh 501     taylor  Dave Taylor     /bin/bash 502     badguy  Test Account    /bin/tcsh 503     test            /bin/tcsh 506     tintin  Tintin, Boy Reporter    /bin/tcsh 507     gary    Gary Gary       /bin/bash 

Notice that it shows many of the administrative accounts (basically everything with a login shell of /dev/null ). If we want to see only login accounts, we'll want to screen out the /dev/null shells :

 $  listmacusers -u -n -r -s  grep -v /dev/null  0      root    System Administrator    /bin/tcsh 505    test3   Mr. Test Three  /bin/tcsh 501    taylor  Dave Taylor     /bin/bash 502    badguy  Test Account    /bin/tcsh 503    test            /bin/tcsh 506    tintin  Tintin, Boy Reporter    /bin/tcsh 507    gary    Gary Gary       /bin/bash 

The badguy account isn't supposed to be there! To find out what's going on there, and to modify NetInfo entries, it's wise to use the Apple-supplied NetInfo Manager application, which can be found in Applications/Utilities or launched from the command line with the command

 open -a "NetInfo Manager"