Create and access shell variable having a name created by another string

This took sometime to find. Apparently this was not something possible with any direct way. I wanted to have 2 dimentional array but in the end i decided to use dynamic strings to create variables which would simulate the 2d array.

Say i want n variables like “test1,test2,test3 …… testn” where n is decided at the time the script it running. So what I should do to create the variable is pretty simple. I will show you how to create the nth variable.

say,

$ n=123

$ let test$n=$n*2

at this point there is a variable now ‘test123’ and it have the value 246. to get the value is a little tricky. This is what took me a lot of time to find. In the end i found the solution in http://www.usenet-forums.com/linux-general/78879-shell-script-variable-variable-name.html.

First you have to create a variable which contains our dynamic variable name.

$ varName=test$n

Now the variable “varName” contains our  dynamic variable name. If you print the value of this variable

$ echo ${varName}

test123

but if you specify “!” mark infront of our variable then the value denoted by the variable whos name is the value of “varName” is shown.

$ echo ${!varName}

246

well thats it actually. Hope this saved some time for someone.

Tags: bash create variable from string, dynamic string to create variables in bash script, dynamically create variables in bash script, new variable using custom string