The book is structured, as its name suggests, into two distinct parts, one for each programming language, BCPL and C. The major topics concerning the programming languages--declarations, commands, structure, expressions, operators, libraries, programming examples and techniques--are briefly presented in chapters 1 to 4 for BCPL and in chapters 6 to 9 for C. In addition, chapter 10 emphasizes the use of the C programming language with the UNIX operating system. The logical relation between these two main parts is presented in chapter 5, which introduces the programming language B, closely related to BCPL and C. The introduction presents the programming language CPL and its connection to BCPL and C. The two appendices illustrate the syntax for each language in the form of easy-to-understand diagrams.

The book provides a concise definition of the system programming languages BCPL and C and emphasizes their close connection with and the features they have inherited from CPL (the language from which they are thought to have descended). The essential concepts of the programming languages--the block structure, data type and scope, the parameter substitution mechanism, left and right values, input and output operations, and the connection of separately compiled modules--are explained well and in an easy-to-understand way that requires no special background on the part of the reader. The book provides examples of the same programming algorithms in both languages and also gives examples of several different features of each language. So I consider this book to be useful for beginners who want a brief overview of both BCPL and C.

However, this book is primarily directed at those who know BCPL and C. They will find in this book a concise presentation of the evolution of concepts concerning the system programming languages exemplified in CPL, BCPL, B, and C. BCPL--with its typeless, oversimplified structure--is deeply connected to low-level programming languages from an early period in the conception of system programming when the efficiency of the generated code was crucial. C--with its complex, strongly typed, structure--is essentially a high-level programming language. This shows that system programming is no longer vitally connected to the efficiency of the generated code--a new orientation imposed both by the technological evolution of recent years and by the demand for quick improvements in operating system programming. The worldwide success of the UNIX-like operating systems--fully based upon the system programming language C--is a strong indication of this new orientation. Moreover, this success has also, definitively, imposed C as a general high-level programming language.