h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Worldwide assistance needed to help me name a book I once read and would like to read again but can't remember the title (must have been good eh?) It was about this guy, born in Edinburgh, father wants him to become a lawyer or a solder or something. Prefers younger brother to this main character, but that's the way families go - anyway this guy goes into the war as a photographer and then goes on to make 'real' war movies for the new cinema-going public but is ousted by another movie guy who makes up the war scenes, trenches,mud guts blood,etc.for his films because it is more sanitised for the fragile public who aren't 'over there' in it up to their necks, poor s**s. But it is this 'phoney' guy who gets all the acclaim, and our good guy goes gradually down the pan. And so the story goes on, a few marriages, more films, no money et al. So, OK, what is the title of this wretched book? Please.