Encrypt and decrypt .zip files on Mac OS X

I just needed to compress and encrypt some files on Mac OS X. The following command does that:
zip -ejr TARGET SOURCEFOLDER
This will ask for a password (twice to confirm it), encrypt and compress the sourcefolder and put it into a file named target (and auto add the .zip extension).

To unzip it do this:
unzip SOURCE -d TARGETFOLDER
This will ask for the password, decrypt and uncompress it into the targetfolder.

How to find your external ip address from the command line

I often need to know what the external IP address for a client is. Thus I’ve cobbled together the following script. Simply copy the code below into externalip.cmd and when run from the command prompt it will do two things for you:

  1. the script will display the external IP address
  2. the script will set the environment variable ExternalIP to be whatever that IP is


@echo off
:: Find out what the External IP address is
:: Create the .vbs file first
Echo Option Explicit >externalipaddress.vbs
Echo Dim http : Set http = CreateObject( "MSXML2.ServerXmlHttp" ) >>externalipaddress.vbs
Echo http.Open "GET", "http://whatismyip.org", False >>externalipaddress.vbs
Echo http.Send >>externalipaddress.vbs
Echo Wscript.Echo http.responseText >>externalipaddress.vbs
Echo Set http = Nothing >>externalipaddress.vbs
:: run the resulting .vbs script and set the enviroment variable
for /f "skip=2 " %%G IN ('cscript externalipaddress.vbs') DO (Set ExternalIP=%%G)
:: Display the enviroment variable
Echo External IP is %ExternalIP%
:: tidy up and remove the temp file
del externalipaddress.vbs /q

Let me know if you find this useful, or if you can improve on it I’d love to hear from you.

Reading the Registry from the Command Line

Often I need to check windows registry values, for example, to see if an addon is working.

From the Microsoft Windows command line (Start | run | cmd) it is easy to see what value a registry key has:

REG QUERY "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\MS Project\Addins\Mindjet.Mm8MsProject.AddIn.4" /v "LoadBehavior"

In this example above, we see if the Mindjet Mindmanager add-on is loaded or not in Microsoft Project.

Using registry values in scripts

I’m often writing scripts to do stuff. It makes my job easier. I’ve often wanted to be able to script the discovery of registry values in the Windows Registry.

Thus here is a short example on using the vanilla windows command line to find the value of a Windows registry key. From my testing these commands are all present by default in Windows XP, Vista, 7, Server 2003 and Server 2008.

Assume we want to find the Microsoft Windows Common Files directory. Using `Regedit` we can find that here: `HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\CommonFilesDir`

So the first thing we want to do is query the registry, we do that with the command line tool `reg` as follows ([more about reg][]):

[more about reg]:http://www.petri.co.il/reg_command_in_windows_xp.htm
“Read up on how to use the reg command for more than just a query”

`reg query HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion /v CommonFilesDir >1.tmp`

This will spit out the following into the text file `1.tmp`:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
CommonFilesDir REG_SZ C:\Program Files\Common Files

However, this isn’t of much use in a script. Really, we just want the value of the folder itself, not all the extra info.

So what we do is use the command line tool ‘findstr’ which essentially is a windows regex tool ([more about findstr][]). We use it to do this:

[more about findstr]:http://www.netexpertise.eu/en/windows/findstr-an-alternative-to-grep.html
“Read up on findstr – regex goodness on windows by default”

`findstr /r REG_SZ 1.tmp >2.tmp`

This spits out just the line that contains REG_SZ and puts it into the text file `2.tmp`. Now that we’ve just just the one line, we want to strip the first 32 characters off it. We do this by first setting it as an enviroment variale and then trimming it down using the following two commands ([more on set][]):

[more on set]:http://www.computing.net/answers/windows-2000/use-file-contents-to-set-variables/63174.html
“Using file contents to set enviroment variables”

`set /p CommFiles=<2.tmp` And then we shorten that ([more on trimming][]): [more on trimming]:http://www.dostips.com/DtTipsStringManipulation.php "Read up on using set to trim environment variables" `set CommFiles=%CommFiles:~32%` Then we can echo the result to the screen using: `Echo The Common Files directory is: %CommFiles%` And here it is all in one easy to copy set: --- Set CommFiles=C:\Temp reg query HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion /v CommonFilesDir >1.tmp
findstr /r REG_SZ 1.tmp >2.tmp
set /p CommFiles=<2.tmp set CommFiles=%CommFiles:~32% Echo The Common Files directory is: %CommFiles% --- With a little editing I'm sure that you can turn this to your own uses, pulling out the value of registry keys and using them in script files. You're not limited to this registry key, you can use it to access all sorts of registry keys. Please do tell me what uses you put this to. Enjoy.