To interface with Twitter services I used the Twitter extension located at http://code.google.com/p/python-twitter/, which has a pretty straightforward API.

The script shown below gives you back what average percentage of your last 20 tweets have been wasted.

import  twitter
import  sys
 
if len(sys.argv) != 2:
        print   "Provide a Twitter Username as Argument"
        exit(-1)
 
api = twitter.Api()
st = api.GetUserTimeline(sys.argv[1])
sum = 0.0
for s in st:
        sum += (140.0 - len(s.text.encode("utf-8")))/140.0
 
print "%s internal fragmentation is %.2f%s" % (sys.argv[1], round(sum / len(st) * 100, 2), "%")

And now some results:

$ python twinternal.py GabrielGonzalez
GabrielGonzalez internal fragmentation is 39.89%
$ python twinternal.py 48bits
48bits internal fragmentation is 36.79%
$ python twinternal.py reversemode
reversemode internal fragmentation is 38.72%
$ python twinternal.py aramosf
aramosf internal fragmentation is 32.41%


• Checking for adminstrator privileges:

userInfo::getAccountType

Pop $0

StrCmp $0 “Admin” +3

MessageBox MB_OK “Debe tener privilegios de administrador para correr este programa de instalación: $0″

Return

StrCmp $0 “Admin” +3

MessageBox MB_OK “You need Administrator privileges: $0″

Return

This chunk of code will pop up a windows with the propoer notification. The StrCmp sentence compares the $0 variable poped from the stack against “Admin” and if they are equal continue the execution with the 3rd line of code, the one below Return.

• Downloading and Executing, e.g. an external installer:

NSISdl::download /TIMEOUT=30000 “http://www.advansen.com/this/is/a/test/advansen.msi” “$INSTDIR\advansen.msi”

Pop $R0 ;Get the return value

StrCmp $R0 “success” +3

MessageBox MB_OK “Download failed: $R0″

Quit

ExecWait  ’”msiexec” /i “$INSTDIR\advansen.msi” /quiet’

• Unziping :

To use the unzip feature you need to download the unzip external plugin, follow the installation guidelines (basically copying the dll to the plugins directory) and that’s it.

nsisunz::Unzip “$INSTDIR\squid.zip” “C:\”

Pop $R0

StrCmp $R0 “success” +2

DetailPrint “$R0″

• Modifying the environment variables:

Adding to PATH

${EnvVarUpdate} $0 “PATH” “A” “HKLM” “C:\some\path”

Removing a PATH

${un.EnvVarUpdate} $0 “PATH” “R” “HKLM” “C:\some\path”

To use the code above you also need external help, just download the EnvVarUpdate extension and will able to update the $PATH variable easily

• Download files
• Unzip Files to a specific folder
• Execute external installers
• Modify Environment Variables

Since NSIS supports plug-ins there are quite a few available which provide extra functionalities such as the unzipping one.

Before going into these extra features, which will be subject of a new post, I prefer writing down how a more complex script is structure, just to keep in to the future.

NSIS is structured in pages (page == panels show each time a “next button” is clicked), most of them are predefined, where you can only change tittle or add extra text in them. Following are the pages definition using the MUI2 interface:

!insertmacro MUI_PAGE_LICENSE “path\to\license.txt”

!insertmacro MUI_PAGE_COMPONENTS

!insertmacro MUI_PAGE_DIRECTORY

!insertmacro MUI_PAGE_INSTFILES

Except for the components page which is configured using the section described in the previous post.  Each Section name will appear as a component with its corresponding checkbox, groups can also be specified and the code inside each section will be only executed if the component is checked:

SectionGroup “Extra Plug-ins”

Section “Spreadsheet”

SectionEnd

Section “PDF”

SectionEnd

SectionGroupEnd

A section declared as follows is executed always :

Section “”

SectionEnd

The next chunk of code creates an entry in the program’s menu:

CreateDirectory “$SMPROGRAMS\Advansen\”

CreateShortCut “$SMPROGRAMS\Advansen\uninstall.lnk” “$INSTDIR\uninstall.exe”

And in order to execute external installers or additional programs the ExecWait sentences provides an easy way to achive that. In the next line python uninstaller is called with the quite flag so no window pops up:

ExecWait  ’”msiexec” /uninstall “$INSTDIR\python-2.6.2.msi” /quiet’

NSIS comes with a compiler which parses the sentences writting in its own language and produces a pretty decent installer. It also has a look-and-feeling similar to latets Windows versions, so it was the perfect choice!

The scripting language is really simple, we can generate a simple installer with only the next few lines:

OutFile “simpleAdvansenInstaller.exe”

InstallDir $DESKTOP

Section

SetOutPath $INSTDIR

WriteUninstaller $INSTDIR\uninstaller.exe

CreateShortCut “$SMPROGRAMS\simpleAdvansen.lnk” “$INSTDIR\uninstaller.exe”

SectionEnd

Section “Uninstall”

Delete $INSTDIR\uninstaller.exe

Delete $INSTDIR\test.txt

Delete “$SMPROGRAMS\simpleAdvansen.lnk”

SectionEnd

After compiling the script with the tool NSIS package’s comes with, two executables are generated:

simpleAdvansenInstaller.exe

Which will copy the uninstaller.exe to the Installation Dir set up to the Desktop and will add an entry in the Programs Menu for the uninstaller.

uninstaller.exe

Will delete itself and remove the entry in the Programs Menu.

NOTE: NotePad++ highlights the syntax of NSIS as well.