Download GMS CLI from the usual place, i.e. go to Console Panel | Management | Settings screen of GMS, and click on the link "Download CLI Client" to your Windows of Linux system
If the zip file was downloaded on a Windows system, scp the downloaded CLIClient.zip to your Linux system in a folder say ~/gmsCLI
Unzip the zip file using the command "unzip CLIClient.zip" this will unzip the file maintaining the folder hierarchy in ~/gmsCLI folder
Convert client.sh from DOS file to Linux file (i.e. correcting for the end-of-line character) by running the command "dos2unix client.sh"
Setup execute permission for client.sh (command: "chmod +x ./client.sh")
Make sure Java JRE 1.6 is installed and is in the path on your Linux system, i.e. the command "java" does not complain
Start using the GMS CLI on the Linux system using the command "client.sh" see the Administration Guide for use of client.bat for Windows for more information, and replace client.bat with client.sh for Linux