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Archives For 30 November 1999

Sed inline editing different on Mac OSX?

18 September 2012 — 5 Comments

Sed is very powerful, I use it a lot on Linux servers I manage. Today I was working on a local git repository on Mac OSX Mountain Lion when I run into some trouble.

Usually, to replace text in a file with new text I run:

sed -i 's/Find this text/Replace with this/' file_to_replace_in.txt

While this works on Linux, it does not on Mac OSX:

sed: -i may not be used with stdin

The manpage on OSX says:

Edit files in-place, saving backups with the specified extension.
If a zero-length extension is given, no backup will be saved.

Aha, it wants to save a backup file. So I changed my command to:

sed -i '.bak' 's/Find this text/Replace with this/' file_to_replace_in.txt

This works, although it leaves a backup file ‘file_to_replace_in.txt.bak’ behind. This is great if you’re not sure, but can be annoying as well. To stop it making backups you specify an empty extension, like so:

sed -i '' 's/Find this text/Replace with this/' file_to_replace_in.txt

This allows me to quickly find & replace again, like when working on Linux šŸ™‚

In Mac OSX ,
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OpenVPN on Mountain Lion: Tunnelblick alternative Viscosity to the rescue?

3 August 2012 — 4 Comments

Last week I wrote a small blog about OpenVPN on OSX Mountain Lion using Tunnelblick. I managed to get things to work using the latest Tunnelblick beta. But after a week working with it, I’m not too happy how it works right now.Ā The two issues I have are:

1. DNS servers do not always get set properly, it feels unstable to me. I’ve seen /etc/resolv.conf with the right content, but still the old DNS servers were used by Mountain Lion. This is annoying: while connected to the vpn, hosts behind it do not resolve because the DNS server advertised by the OpenVPN server is not being used. This happened a few times last week, although most of the time it works ok. What goes wrong more often is the opposite: when disconnecting the connection, the OpenVPN advertised DNS server is still being used; but since we’re disconnected, it doesn’t resolve anymore and so nothing works. I’ve then to manually restore the right DNS servers. No fun, but I accepted it for now. I thought there’d be an update soon enough that’d solve this.

2. Problem two is more annoying: the connection is not stable, it’s slow and when working in a shell it is annoying to wait for the cursor to move. It frustrates me. I’d already blamed the guys in the office for heavy downloading only to discover it was Tunnelblick that was the problem. Sorry guys šŸ˜‰ Connections to public hosts are fine by the way; I wasn’t really able to pinpoint this issue. It kept me from working effectively.Ā If somebody knows what to do to get this working properly, let me know!

So I thought it’d be wise to look for an alternative, and I came acrossĀ Viscosity. I just wanted to compare and see if it has the same issues. Don’t get me wrong: I always prefer open source software, but it does have to work. Tunnelblick and Mountain Lion clearly doesn’t work for me. Viscosity is $9 for a license, that sounds ok to me.

Downloading and installing is easy, like any other OSX app you open the dmg and drag the application to the application folder. That’s it. What surprised me was that it has an import feature that imports from Tunnelblick. One click, that’s all..

Now that’s cool. From the upper menu, you can now connect. I just works, a few seconds later I’m connected and.. DNS is handled properly. I tried connecting, disconnecting and all but can’t find any problem. It uses the OpenVPN specified DNS servers while connected, and the DHCP specified DNS servers while disconnected. Just like when I was running Tunnelblick on Lion. Also, I haven’t seen the slow connection issue. It’s a bit early to tell if that is gone for good. Since I have 30 days to try Viscosity, I’ll soon enough know šŸ™‚

For me this is a fast en good solution. I hope Tunnelblick is able to sort out what goes wrong with Mountain Lion. Otherwise Viscosity probably has a lot of new users to welcome in the coming months. Kudos to the Sparklabs team!

Update:Ā I did go back to Tunnelblick a few times but had no lock and didn’t want to spend more time on it. Then I bought Viscosity that just works and has been stable from the start.

In Mac OSX , , , ,
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Overriding default keyboard shortcuts in Mac OSX (Mountain Lion)

29 July 2012 — 15 Comments

I’ve upgraded my 3 year old MBP with a fast SSD. I decided to install from scratch instead of migrating or cloning the old disk. The good thing is that everything is now fast and clean. The downside is that allĀ customisationsĀ I did over the past years are also gone.

One thing IĀ customisedĀ was shortcuts. I forgot how easy this can be done in OSX, so I’ll describe it below so others can benefit as well.

For example, I want the shortcuts in Terminal for Next and Previous tab to be CMD+right arrow, and CMD+left arrow. In Terminal you can see the default shortcuts for this in the menu:

It looks ok, but you cannot directly press ‘}’ on most keyboards; It’s SHIFT+], so this makes the default shortcut CMD+SHIFT+]. I prefer a shortcut with just two keys. To change these you’d go to:

System Preferences | Keyboard | Keyboard Shortcuts

From the left, choose ‘Application Shortcuts’ and then click the + icon to add a new shortcut. First, select the application you want to change the shortcut for, ‘Terminal.app’ in this example. Then, specify the exact menu title for the command you’d like to change the shortcut for. As you can see above, you’d enter ‘Select Next Tab’ to change that command. Repeat for ‘Select Previous Tab’. Just press the shortcut and it will appear in the box. Afterwards it should look like this in the keyboard preferences pane:

Now, go back to the Terminal application and have a look at the same menu as before. It should now list the shortcut you just added.

Try changing tabs by pressing CMD+left/right arrow.. it works!

One thing to note, it that the shortcuts I used in this example, by default belongĀ to changing windows instead of tabs. When you want to change windows in Terminal using a shortcut, you’ll need to add new shortcuts for these as well.Ā Alternatively, you use the CMS+` shortcut which still cycles through your windows, it just cannot go back. For me this works ok as this works in any application.

Changing shortcuts in Mac OSX is easy and allows you to make them work exactly as you prefer. I’ve done this in Mountain Lion, but I believe this can be done in Lion as well.

In Mac OSX , , , ,
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Fixing OpenVPN/Tunnelblick DNS issues on OSX Mountain Lion

28 July 2012 — 7 Comments

I just upgraded to OSX Mountain Lion and had some trouble this morning getting my OpenVPN connection (using Tunnelblick) to work. It would connect, but the DNS resolving was unstable. I managed to get it to work on the latest stable byĀ changingĀ the DNS-server setting to ‘set nameserver 3.0b10’ but then internet traffic would not work. The best solution for me at the moment is to upgrade toĀ Beta release 3.3beta16Ā 3.3beta18.

After upgrading, everything works as expected!

More info:

  1. Mountain Lion DNS issues with Tunnelblick
  2. Discussion the issue

Update: see this blog I wrote as wellĀ (experience after one week)

Update 2: TunnelBlick 3.3 beta 18 has just been released and the release notes state it has fixed more Mountain Lion bugs.

In Mac OSX , , ,
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Setting locales correctly on Mac OSX Terminal application

10 July 2012 — 69 Comments

I’ve had some trouble when using the Mac OSX Terminal app for some time now. Until today, it just gave me some annoying warnings from time to time. Like when installing an application with apt-get in Debian:

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LC_CTYPE = “UTF-8”,
LANG = “en_US.UTF-8”
are supported and installed on your system.
perl: warning: Falling back to the standard locale (“C”).
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory

It did work, so nothing too serious. I’ve also found applications, like iotop for example, that refuses to start when LC_ALL was unset. But a quick

EXPORT LC_ALL=$LANG

made the application start, so I didn’t take the time to investigate it further. Today I run into a more serious issue that cost me quite some time to figure out.

I had stopped the pure-ftpd deamon to do some maintenance and then started it again. It did start without error, but connecting failed:

server:~# ftp ftp.server.nl
Connected to ftp.server.nl.
perl: warning: Setting locale failed.
ftp>

Nothing had changed in the ftp configuration. After some debugging and trial & error, I found out that when I started the deamon from within a shell on Ubuntu it worked, but when I started it within a shell on my MacBook, it didn’t.

When looking at the locales I found:

server:~# locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.UTF-8
LC_CTYPE=UTF-8
LC_NUMERIC=”en_US.UTF-8″
LC_TIME=”en_US.UTF-8″
LC_COLLATE=”en_US.UTF-8″
LC_MONETARY=”en_US.UTF-8″
LC_MESSAGES=”en_US.UTF-8″
LC_PAPER=”en_US.UTF-8″
LC_NAME=”en_US.UTF-8″
LC_ADDRESS=”en_US.UTF-8″
LC_TELEPHONE=”en_US.UTF-8″
LC_MEASUREMENT=”en_US.UTF-8″
LC_IDENTIFICATION=”en_US.UTF-8″
LC_ALL=

Notice the two errors at the top. I talked to a colleague about this and he suggested looking at the Terminal app settings. There I found a setting called “Set locale environment variables on startup” which was activated. The setting is located in Preferences | Settings | Advanced. I’ve unchecked the button now as you can see in this screenshot:

When closing the Terminal app, and reopening it again, I tried again:

server:~# locale
LANG=en_US.UTF-8
LC_CTYPE=”en_US.UTF-8″
LC_NUMERIC=”en_US.UTF-8″
LC_TIME=”en_US.UTF-8″
LC_COLLATE=”en_US.UTF-8″
LC_MONETARY=”en_US.UTF-8″
LC_MESSAGES=”en_US.UTF-8″
LC_PAPER=”en_US.UTF-8″
LC_NAME=”en_US.UTF-8″
LC_ADDRESS=”en_US.UTF-8″
LC_TELEPHONE=”en_US.UTF-8″
LC_MEASUREMENT=”en_US.UTF-8″
LC_IDENTIFICATION=”en_US.UTF-8″
LC_ALL=

No more errors! I tried restarting the pure-ftpd deamon from my Terminal app and it now works as expected. Even the warnings and errors when installing applications in Debian (apt-get) are gone. In fact, it seems this is the way it is supposed to work.

Glad I’ve fixed this šŸ™‚

Update:Ā As Reza mentions in the comments, it’s also possible to fix this problem on the server side. This is the best way to go if you want to fix this for your users. Thanks Reza!

In Linux sysadmin, Mac OSX , , , ,
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