Per the Windows and Linux threads, what commands do you find most useful in Mac OS X Server (or Client)?

  • agreed, this site seems to be far more negative that stackoverflow, people seem poised to 'down' any post they don't think meets their standards - it's enough to make me walk away. – Chopper3 May 12 '09 at 13:15
  • thx, chopper3. maybe it was voted down for being mac related. i can understand not wanting to see a lot of apple stuff, but really just add /ignore "mac" to your tags, and it's sorted – username May 12 '09 at 13:23
  • 2
    there's loads of apple specific stuff on this site, people here just seem to enjoy being negative. – Chopper3 May 12 '09 at 13:29
  • 2
    to be expected i suppose... we are sysadmins :-) – username May 12 '09 at 13:32
  • 1
    I like your username...username :) – Chopper3 May 12 '09 at 13:35

55 Answers 55

say "some text"

Famously used for getting people back into their apartments, say takes your arguments and reads them aloud through the audio output device.

  • 4
    +1 for xkcd content – username May 14 '09 at 12:27
  • 4
    And it speaks very well -- see macosxhints.com/comment.php?mode=view&cid=107211 for a list of phrases such as My name is Dr. Smith and I live on Smith Dr., The soldier decided to desert his dessert in the desert and Since there is no time like the present, he thought it was time to present the present :-) – Arjan Aug 11 '09 at 14:57

pbpaste and pbcopy to interact with the pasteboard (aka clipboard).


# copies the directory listing
ls -l | pbcopy

# get pasteboard lines containing foo and save them in a_file
pbpaste | grep foo > a_file

I think they default to using the macroman encoding, so if you want UTF-8 (which you do) you should check out these links:


Lets you monitor file system activity. Handy if you want to see what files some app creates. See http://rentzsch.com/macosx/fs_usageIntro for more explanation.

open .

Opens a finder window in the current working directory.

  • for launching other apps, use something like: open -a "activity monitor" – username May 13 '09 at 9:24
  • Freunde schöner Götterfunke...I mean, thank you, thank you, thank you!! I was looking for a Windows like "start ." and this is it! – Daniel Schneller May 19 '09 at 11:09
  • 'open filename' acts the same as double-clicking on a file in the Finder -- it'll launch the associated application and open the file. – Clinton Blackmore May 25 '09 at 18:44

From the command line, I like having the ability to:

Create and burn a "universal" CD/DVD:

$ mkisofs -allow-multidot -allow-leading-dots -d -hide-rr-moved \
-l -joliet-long -R -T -v \
-V VOLUME_NAME -o output.iso root-cd-dir/
$ hdiutil burn -noverifyburn output.iso

Create an ISO image from a CD/DVD:

$ diskutil unmountDisk /dev/disk2s0
$ dd if=/dev/disk2s0 of=cdname.iso bs=32m

Being able to forget the otool command when I'm seeking ldd:

$ alias ldd='printf "Sending command to \'\''otool -L\'\'' --\n" && otool -L'

Mount a disk image from the command line:

$ hdid diskimage.dmg (or .iso)

Use preview to access a man page:

$ man -t rsync | open -f -a /Applications/Preview.app
  • 1
    +1 for the manpage / Preview hint. Awesome. – Sam Halicke Oct 26 '09 at 8:35

The 'airport' CLI utility is my favorite. See http://osxdaily.com/2007/01/18/airport-the-little-known-command-line-wireless-utility/. It will show you details like the signal level, noise level, and the BSSID of the AP you're associated to.

  • 1
    Cool. Eg: /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I Shows you detailed information on signal quality, noise, security, and other WiFi network attributes. – username May 12 '09 at 13:30
ipconfig getpacket en0

Displays network configuration for the primary Ethernet interface (en0).

If you're used to Windows and think "ipconfig" is broken - it's not ;-) You just need to add a couple arguments

  • 4
    Of course, if you're used to Linux, 'ifconfig en0' works just as well. – Tim May 14 '09 at 11:38
  • Or use en1 if you're on wireless. – Dana the Sane Feb 7 '11 at 18:39
drutil tray open

Invaluable (over ssh) when there's no keyboard connected since the eject button on Apple optical drives isn't accessible from outside the case.


It can't be said enough, "open" is great. You can open documents in their GUI program and you can select the GUI program with -a as well. For example,

open -a vlc movie.avi

will open VLC and tell it to load movie.avi in your current dir.

open movie.avi

would open it with whatever program is the default. If you just want to open a program, you can do that too:

open -a system\ preferences

will run System Preferences. You can open Urls too:

open vnc://myserver:5900

will open Screen Sharing and connect to myserver.

Check out

man open

to see all flags you can use.


Update your mac from the CLI.


Configure everything you find in the Network Preference Pane in System Preferences on the command line. Makes writing scripts, or doing things remotely much easier.

sudo changeip -checkhostname

Checks that forward and reverse DNS resolution are healthy, and often shows you the command you can use to fix the problem. If it says "the names match, there is nothing to change" you're in good shape. Vital if you ever change your server's network configuration. Also important to use this before you promote your server to an Open Directory Master.

dscacheutil -flushcache

I find myself using that one heaps to flush the DNS cache, on 10.5+.

  • Of note, this only works in Mac OS X 10.5 – Chealion Oct 7 '09 at 23:08
  • I just checked, it also works on 10.6. – Bruce McLeod Oct 9 '09 at 0:53
  • Upvoted as I find myself having to run this more often than not, however don't remember having to flush the Linux or Windows DNS cache. Perhaps OS X is particularly aggressive at DNS caching? – petertonoli Dec 31 '09 at 23:42

Ping all devices on your subnet


shows who has logged into a system, how long they used it, and when the system has been restarted.

Here is a sample of the output:

clinton   ttys000                   Thu May 28 22:33   still logged in
clinton   console                   Thu May 28 08:05   still logged in
reboot    ~                         Thu May 28 08:05 
shutdown  ~                         Wed May 27 20:15 
clinton   console                   Wed May 27 17:33 - 20:15  (02:42)

wtmp begins Thu May 14 09:26 

Command line version for secure delete.


list open files

Handy when you want to eject your USB drive and are told that it is in use and to please quit all applications and try again.

$ sudo lsof /Volumes/CLINTON
bash    55966 clinton  cwd    DIR  14,12    16384    2 /Volumes/CLINTON
lsof    56042    root  cwd    DIR  14,12    16384    2 /Volumes/CLINTON
lsof    56043    root  cwd    DIR  14,12    16384    2 /Volumes/CLINTON

In this instance, I had cded onto the drive and so bash was accessing the volume.

Note that if you see 'mds' entries, it means that spotlight is indexing the drive.


The Command-Line Administration guide put out by Apple is invaluable.

Googling for "command line administration mac" gives good results.

Command-Line Administration for Mac OS X 10.5, 10.4, and 10.3.

Other useful guides are at http://www.apple.com/server/macosx/resources/.



While not specifically a Mac resource, it is using the icon for the Terminal, and most of the list of really useful commands will work.

osascript -e 'tell application "AppName" to quit'

Lets you quit an application from the shell.

osascript -e 'tell application "Finder" to sleep'

Useful last line of a long shell script, puts Mac to sleep when script is done. I have it aliased to iSleep.

pbpaste | script.sh |pbcopy

takes contents of pasteboard (edit->copy) and pipes it to script.sh. The results are put onto the pasteboard for you to edit->paste into a document.


this will let you see what sort of MCX (Managed Client) settings are being applied to a client machine.

[The GUI equivalent is to go to System Profiler, and, under the Software section, click on "Managed Client".]

It is useful to determine if a machine is managed and to see if it is getting the settings you expect.


Displays the currently installed version and build of Mac OS X.


Give you the same results as you get when you choose About This Mac -> More Info, only on the command line.


system_profiler -usage

or looking at the man page will give you tips on how to use it.

A couple of examples:

system_profiler -xml > MySystem.spx
# and later,
open MySystem.spx  # or just double click on it in the Finder

this will dump the system profile to a file which can be looked at later on a different machine.

system_profiler SPUSBDataType

Tells you about all your USB devices (including their Vendor and Product IDs, which can aid in tracking down drivers).

system_profiler SPUSBDataType | grep "Product ID" -c

will tell you how many USB devices are plugged in (including internal USB devices), which is useful to see if the computer sees a device (or, if, say, Parallel's grabbed it or it is dead.) [Do note that in the System Profiler GUI App, you can choose View -> Refresh from the menu to update the list; that may just be easier.]

system_profiler SPHardwareDataType

will get you basic hardware info (useful for asset tracking), and

system_profiler SPHardwareDataType | grep Serial

will give you the machine's serial number.

ifconfig en0 ether 00:00:00:00:00:00

Changes (spoofs) MAC address until next reboot

df -h

To check how many disk space I currently have on all the disk.

dns-sd -B _ssh
dns-sd -B _rfb
dns-sd -B _services._dns-sd._udp

List servers advertising in Bonjour. The last suggestion lists the types of service that you can list. The listing is live, hit Ctrl-C when you've seen enough.

The same command comes in recent Linuxes and in the Bonjour SDK for Windows.

opendiff file1 file2

Runs FileMerge (a graphical diff that comes with Apple Developer Tools) on file1 and file2.

sudo opensnoop

in Leopard and newer, reports which processes open files, whether successfully or not. You can ask it to look at all files being opened across the system, by a specific process, or if any process is opening a given file, with different sorts of timestamps, and to show if errors occur.

Here are some more details:

opensnoop is a dtrace script; there are many others in /usr/bin that look at things like which system calls a process is making, what processes it is creating and what I/O it is doing. Run apropos DTrace for a list, and look at man pages for details.

I found out about opensnoop when struggling to diagnose why a Comic Life Magiq 1.1 was crashing on OS 10.5.8 for users with network accounts.

I ran (several times, on different accounts, via ssh):

sudo opensnoop -e -n Comic > output.txt

The last file opened by network users was something like this (with a full path):


which reminded me that Safari 5.0 was crashing for network users, and we worked around it by either managing a preference to not cache favicons or by redirecting a file. Apple apparently fixed the issue in Safari 5.0.1, and when I upgraded to Safari 5.0.2 yesterday, it fixed the crash for Comic Life Magiq users.

sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -restart -agent

Starts the Remote Desktop service (useful if you only have SSH access but want to do something using the GUI on your client Mac). For more options, see: http://support.apple.com/kb/HT2370

drutil eject

will eject a CD.

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