Saint Jack is a 1973 novel by Paul Theroux that was adapted into a 1979 film of the same name.
It tells the life of Jack Flowers, a pimp in Singapore.
Feeling hopeless and undervalued, Jack tries to make money by setting up his own bordello, and clashes with Chinese triad members in the process.
A film adaptation directed by Peter Bogdanovich was released in 1979.