Extracting nth length of character from a variable to another variable

[hayloiuy]

Example, I want to extract the first four character from serial and store it into version.

Code:

serial= 10001100
version=...(codes)....
echo $version


output in the terminal:
1000

Just to show you guys i havent been lazy...

#!/bin/bash

serial=10110011
echo $serial> serial.txt

version= cut -c1-4  serial.txt

echo $version

but this code saves the value into a text file. I want a code that does not save into any file whatsoever. Help? Thanks.

[heliumhe]

Example, I want to extract the first four character from serial and store it into version.

Code:

serial= 10001100
version=...(codes)....
echo $version


output in the terminal:
1000

Just to show you guys i havent been lazy...

#!/bin/bash

serial=10110011
echo $serial> serial.txt

version= cut -c1-4  serial.txt

echo $versiong

but this code saves the value into a text file. I want a code that does not save into any file whatsoever. Help? Thanks.

Something like this?

#!/bin/bash

serial=10110011
version=$(echo serial|cut -c1-4)

echo $version

[Rubberman]

Actually, you can do this pretty easily by using back-quotes around the cut command so you can take the output and assign it to the $version variable. IE,

#!/bin/bash

serial=10110011
echo $serial

version=`echo $serial | cut -c1-4`  

echo $version

Remember, however, that $version is only going to be visible inside this script. If you want to make it available in your runtime environment, then source it. IE, file getversion.sh =

serial=10110011
echo $serial

version=`echo $serial | cut -c1-4`  

echo $version

Now, you can see $version if you do this from your command line:

source getversion.sh