Can't Open pdf file using open in Ubuntu

Hi all,

I have recently created a GUI where I have to open a pdf help file using a push button.

I am using "open helpGUI.pdf" command for it. I am able to open the help pdf file on Windows & MAC but cannot open it on the ubuntu platform as this command requires adobe acrobat pdf which ubuntu does not have.

Is there any alternative to this specific problem. Like any other function which I can use for ubuntu to open a pdf file.

Thank in advance!!