Your shirt is the Portuguese m63 pattern, frequently referred to as the Portuguese "all arms" pattern or the "purple lizard" pattern. It was first introduced in 1961 and a variation is still being worn by the Portuguese Marines (although remaining Armed Forces now wear a DPM pattern). There were many types of uniforms and hats produced in this purple variation as well as some color variants, but (as Philip illustrates) there was also a "red lizard" variant that saw use mostly in Africa.
As I recall, shirts like the one you have often had a very tiny size tag in the neck, but it was not sewn in - rather glued to the back with a sticky substance that easily peeled off.
The Portuguese infantry combat jacket is called the dolman.