Hey all!

Recently I came across what seems a quite common problem. Specially if you travel or have had to connect to different networks where you need different configurations to get your job done.

As I got tired of manually changing the IP Configuration from the Network Settings window, my next goal was to create a simple script file that would allow me to do this in a very simple way.

Batch scripting can be VERY tricky, specially if you are not careful with the syntax, and you are using it as you are learning :).

So here it goes:

@ECHO OFF

set varIP=192.168.0.2
set varMK=255.255.255.0
set varGW=192.168.0.1
set vardns1=127.0.0.1
set intID="Wireless Network Connection"

ECHO Setting IP properties.

netsh int ipv4 set address %intID% static %varIP% %varMK% %varGW% 1

ECHO IP Properties set.
ECHO Setting DNS Properties

netsh int ipv4 set dns %intID% static %vardns1%

pause

Easy.

Now, this solves the issue, but unfortunately I needed a couple more files for different tests, so I decided to write something a bit longer (and tidier).

First, I want to know what interfaces are active, and easily be able to choose them. Hence, the following:

@ECHO OFF

ECHO Choose the interface (input the id):

setlocal EnableDelayedExpansion

FOR /F "tokens=1,5,*" %%A IN (‘netsh int ipv4 show interfaces’) DO (
SET initString=%%A

REM These next three lines just format the output table nicely,
REM they will be explained later.
call :strlen resLen !initString!
call :getNiceString resultString !resLen! 5 !initString!
ECHO !resultString! %%B %%C
)

REM Get the input from the user
set /P intID=Type interface ID: %=%

And the output nicely put:

Note in the code above that the FOR loop goes through all each line of what comes out of the ‘netsh int ipv4 show interfaces’ command, and this gives a lot of unwanted information.
I just want the first and fifth columns, which is why I select the 1^st, the 5^th and whatever comes after that (in case an interface has a name consisting of 1+ words). Note that by default, ” ” (space) is taken as the delimiter.

Now that I have the interface, I want to know whether to choose the default DHCP configuration, or whether I need a specific profile:

[bat firstline=”19″] ECHO Do you want DHCP? (y/n)

set /P answer=Type answer: %=%

if "%answer%"=="y" (

REM configure IP and DNS for the given DHCP
netsh int ipv4 set address %intID% dhcp
netsh int ipv4 set dns %intID% dhcp

) ELSE (
ECHO Choose your configuration file:
set /a var=1
REM list the files in the directory which contain ".bat" in their names
REM and save them in an array (there are no arrays in batch scripting), explained later.
FOR /F %%F IN (‘DIR /B /oN^|FIND /i "bat"’) DO (
REM check that the file being listed is not the running file
set varF=false
if %%F == %0 set varF=true
if /I "%%F" EQU "%0.bat"; set varF=true
if !varF!==false (
set __Files.!var! = %%F
ECHO !var! – %%F
set /a var = !var!+1
)
)
REM Ask for the file number
set /P file=Type file number: %=%

REM this might seem confusing at first. The SET __Files.X command
REM where X is a number, returns a line similar to this:
REM __Files.X = some_value. And because "some_value" is what matters,
REM we need to split that line in two tokens. How to do it:
FOR /F "tokens=2* delims=.=" %%A IN (‘SET __Files.!file!’) DO (
ECHO Starting profile %%B
START %%B %intID%
ECHO Profile %%B succesfully started.
)
)
endlocal
pause
goto :eof
[/bat]

Finally, if you check out lines 12 and 13 in the second block of code (“Getting the available interfaces”), the code for those function calls is the following:

[bat firstline=”62″ title=”Printing a table nicely” collapse=”1″] REM the following portion of code is here just to print things nicely
REM gets the necessary number of spaces to add to a string and returns
REM the value in the first parameter.
:getNiceString <resultString> <strLength> <resultLength> <initString>
(
set /a diff = %~3 – %~2
set resString=%~4
FOR /L %%i in (1,1,!diff!) DO (
REM note the space at the end of the following line
set resString=!resString!
REM right here ^
)
set "%~1=!resString!"
exit /b
)

REM gets the length of a string variable
:strlen <resultVar> <stringVar>
(
set string=%~2
set len=0
:loop
if "!string!" NEQ "" (
set string=!string:~1!
set /a len=!len!+1
goto loop
)
)
(
set "%~1=%len%"
exit /b
)
[/bat]

Done!
Now all you need is to put the main file in a folder along with the profile files that you want, and then just select the profile of your choice.
Hope you found this useful!

The main file:

IPSetup

Sample profiles:

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