[Home Page] - [Reviews Main]

Sed & awk by Dale Doherty Recommended

ISBN: 0-937175-59-5       Publisher: O'Reilly       Pages: 395 pp       Price: £20-95.

Programming with curses by John Strang Recommended

ISBN: 0-937175-02-1       Publisher: O'Reilly       Pages: 72 pp       Price: £9-95.

Lex & yacc by Mason & Brown Recommended

ISBN: 0-937175-49-8       Publisher: O'Reilly       Pages: 217 pp       Price: £21-95.

Categories:   awk     unix

Reviewed by Francis Glassborow in C Vu 4-4 (May 1992)

All five programs are extensively available for both UNIX and other platforms. There are GNU substitutes for all of them and versions that run under MSDOS are available both as PD and commercially. It is sad that so many programmers and system users know so little about any of these programs. Each was designed to tackle real problems that programmers and system managers were likely to come across day by day.

Do you have a need to carry out specific types of edit on text files regularly? If so you would almost certainly find the time spent learning to use sed was well spent. Being a programmer you would quickly get to grips with writing appropriate script files to automate much of your regular editing.

The other part of this book is a guide to using awk and similar programs from other sources. Many of the small jobs that require a quick (and dirty) program can be done in awk. The result will run much more slowly than would a C program to do the same thing but you will have made very large savings in development time. The similarities between awk and C mean that if you decide you want an efficient long term program you will be able to convert your awk script to C without too much rethinking.

Basically curses is a C library for controlling a terminal's video display screen from a C program. If you have, or intend to get, one of the public domain versions of curses that are readily available it is well worth including the cost of this book(let) in your planned spending. That way you will have a reasonable manual to go with your free package.

I wonder how often you have realised that a particular task you were programming really wanted a special purpose language. For example, when developing a drop down menu system, you really develop a series of commands and then write functions to carry them out. The end result is that you specify your menus in your own menu language.

lex and yacc are designed to make development of tools for these simple little mini-languages easy. The name yacc is an acronym for yet another compiler compiler. The common mistake is assuming that this implies it is for creating compilers for massively complex eccentric languages. It isn't, though you could no doubt use it for such. yacc and its companion lex (for lexical analysis) are primarily intended to allow quick and easy development of small special purpose languages (I know that a portable C compiler has been developed with them and that the GNU C compiler relies on yacc but that is not what most programmers would be interested in).

If you look in our PD library you will find versions of all the programs and packages covered by these three books. If you want to get to grips with the software these are the books that will help you do so. Conversely, if you buy one of the books our library is a cheap source of software to help you use the book.

I have a definite feeling that many of you might find studying one or more of these items profitable. For some you might just find that you had satisfied your curiosity but for many you would find you had added some valuable tools to your toolbox. As the software is available for MSDOS machines as well as Unix the ignorance of many is no longer excusable.

Mason
Lex & yacc (2nd edition) by Brown & Mason [Recommended]  (Reviewed Jan 1993)