.PP This is a test of the refer program. Because the bibliography supplied by Bell Labs contains nothing but programming references, that will be the subject here. .PP For serious programmers, there are several indispensable reference works. The book describing the C programming language is an excellent starting place for those who already know another language such as Pascal or Fortran.\*([.1\*(.] .ds [F 1 .]- .ds [T The C Programming Language .ds [A B. W. Kernighan .as [A " and D. M. Ritchie .ds [I Prentice-Hall .ds [C Englewood Cliffs, New Jersey .ds [D 1978 .ds [P 34-39 .nr [P 1 .nr [T 0 .nr [A 0 .nr [O 0 .][ 2 book It is rich with examples of programs that work, probably the most valuable resource a programming book can provide. .PP When learning the Unix system, it will be necessary to have a reference guide such as the Programmer's Manual. Section 1 is useful for everyone, but only programmers need sections 2 through 8.\*([.2\*(.] .ds [F 2 .]- .ds [T U\s-2NIX\s0 Programmer's Man\&ual .ds [A K. Thompson .as [A " and D. M. Ritchie .ds [K unix .ds [I Bell Laboratories .ds [O Seventh Edition. .ds [D 1978 .ds [O The version 6 manual is outdated by now. .nr [T 0 .nr [A 0 .nr [O 1 .][ 2 book Be sure to get the Version 7 edition, if you have a Version 7 installation. .PP One of the strong suits of the Unix system is the ability to build parsers and compilers for new languages. Several tools are provided to this end, most notably \fIlex\fP and \fIyacc\fP. For an introduction to the theory involved, see the book by Aho and Ullman on LALR parsing.\*([.3\*(.] .ds [F 3 .]- .ds [A A. V. Aho .as [A " and J. D. Ullman .ds [T Principles of Compiler Design .ds [I Addison-Wesley .ds [C Reading, Mass. .ds [D 1977 .nr [T 0 .nr [A 0 .nr [O 0 .][ 2 book Several of the most unusual Unix software tools, such as \fIeqn\fP, \fIawk\fP, and \fBbc\fP, were developed with the aid of \fIyacc\fP. Of course, the reference of last resort is\*([.4\*(.] .ds [F 4 .]- .ds [T U\s-2NIX\s0 Programmer's Man\&ual .ds [A K. Thompson .as [A " and D. M. Ritchie .ds [K unix .ds [I Bell Laboratories .ds [O Seventh Edition. .ds [D 1978 .nr [T 0 .nr [A 0 .nr [O 1 .][ 2 book as mentioned above.