If you are making changes inside of Eclipse, the pending local changes (in the "Unresolved" folder) should appear automatically, otherwise you will be required to use the Refresh button in the Pending Changes view (click the down arrow beside the refresh button and select "Refresh Sandbox and Remote Changes". You can change what the default action will be when pressing the Refresh button in the Preference page located at: "Team" --> "Jazz Source Control" --> "Changes" --> "Default Refresh Action:".

There is a preference to have changes automatically detected when making changes outside of Eclipse, however this is only available on Widows. The Preference page is located at: "Team" --> "Jazz Source Control" --> "Local Changes" --> "External Changes". This feature depends on support at the OS level which I don't think was available for Linux at the time the feature was added. Additional information on this preference is mention in the following jazz.net article: https://jazz.net/library/article/531.

Eclipse also has similar features that may help, try turning on the "Refresh automatically" option (or "Refresh using native hooks or polling", depending on the Eclipse version) on the "General" --> "Workspace" preference page