My understanding, based on what people who have been there say, is that the prohibitions on knives in the UK and France are being wildly exaggerated. A lot of the legal issues are a matter of context.

Any adult can buy a large kitchen/chef's knife or utility knives at any number of stores. These can amount to virtual short swords in size. You can buy it and carry it home and use it in and around your home for the usual, perfectly legitimate, purposes. Tradesmen are not prohibited in keeping suitable knives for work. Gardeners and groundskeepers can buy, keep and use large knives, machetes and other large edged tools.

On the other hand if your observed carrying it openly on the streets or a subway your going to have some explaining to do. then again if the knife is part of a roll of chef's knives, was kept in their roll and your employed as a chef your not likely to have any problem explaining and being allowed to go on your way. Similarly if the knife is part of a tool kit you use in you trade and you haven't been showing it around your also unlikely to have any problems beyond just answering a few easy questions.

As I understand it even if you have no particular use a pen knife of small SAK generally gets a pass as long as the blades don't lock. And even then your not likely to be questioned by police if you keep it in your pocket.

I was told that an original Leatherman with a non-locking blade is likely to get a pass even though the blade length is a bit long. A judgment call by the police who are likely to give a pass to a working stiff with no record if he works with his hands. But if you fit the description of a thug, drunk or suspicious person they are more likely to confiscate the knife.