When installing or updating an IBM product using Installation Manager and the -repositories option points to an IBM HTTP url, you will need to provide your IBM username and password. One way to provide your username and password is by using the -prompt, which will prompt you to provide your username and password. These examples are based off of a Linux system.

/opt/IBM/InstallationManager/eclipse/tools/imcl 
listAvailablePackages
-repositories http://www.ibm.com/software/repositorymanager/com.ibm.websphere.BASE.v90
-prompt

Note that there is no need to provide your IBM username and password if the -repositories option points to a local directory.

/opt/IBM/InstallationManager/eclipse/tools/imcl 
listAvailablePackages
-repositories /tmp/foo

Instead of using the -prompt option, you can use the -secureStorageFile and -masterPasswordFile options. The secure storage file contains your IBM username and the IBM URL that you are connecting to. The master password file contains your IBM password. First, create the master password file.

echo 'your_password' > /path/to/master_password.txt

Then, create the secure storage file.

/opt/IBM/InstallationManager/eclipse/tools/imutilsc saveCredential
-url http://www.ibm.com/software/repositorymanager/com.ibm.websphere.BASE.v90
-userName your_username
-masterPasswordFile /path/to/master_password.txt
-secureStorageFile  /path/to/secure_storage_file.txt

If the creation of the secure storage file is successful, the following output should be displayed.

Successfully saved the credential to the secure storage file.

Now, you can use the -secureStorageFile and -masterPasswordFile options instead of the -prompt option, and you will not need to provide your username and password on the command line when installing or updating a product.

/opt/IBM/InstallationManager/eclipse/tools/imcl 
listAvailablePackages
-repositories http://www.ibm.com/software/repositorymanager/com.ibm.websphere.BASE.v90
-secureStorageFile  /path/to/secure_storage_file.txt
-masterPasswordFile /path/to/master_password.txt