One great strength and simultaneous challenge of the UNIX system is its wealth of tools and subsystems, notably the multiple languages used to support various operations and scripts, including sed, awk, sh, csh, and now perl. Perl is a worthy addition to these tools for a middle ground of programming. Formed from a blend of features from the UNIX shell sh, C, and awk, perl has become widely used, as indicated by its own newsgroup, conference, published reference book, and this new tutorial.

This book is a member of the excellent practical series of handbooks from O’Reilly, and in that tradition is well suited for hands-on use by any programmer who wants an easy yet complete introduction to perl. The book describes the features and uses of perl by example. It supplements the more complete and definitive Programming perl [1]. This book developed out of a series of classes taught by the author, and it is designed for hands-on learning. It follows a traditional path through the introduction of language features--data, structures, control, and I/O. The more interesting aspects of perl follow, including its higher-level programming features of text manipulation, patterns, files, database, and system (process control) features. Examples often involve system programming or administration. The author does a good job of enumerating the perl support for each area, at a level that builds on and often references knowledge of similar features from other programming environments. For example, in fork/exec, the syntax of the features is given, but the semantics are defined as “what the fork system call does.” This assumption allows the text to be shorter, simpler, and more easily used by its targeted audience.

The book is not a complete reference to perl or to its programming environment, but it is certainly a good, gentle introduction to the foundations of the language. It describes perl 4.0 (5.0 is now out and is a major upgrade). The combination of GNU code and O’Reilly documentation is a boon for the computing community. The source code for perl, and all the exercises, are available online by anonymous ftp; get a copy of this book, and learn a new tool.