| PackageDescription | A fast lexical analyzer generator.
flex is a tool for generating scanners: programs which recognized lexical
patterns in text. flex reads the given input files for a description of a
scanner to generate. The description is in the form of pairs of regular
expressions and C code, called rules. flex generates as output a C source
file, lex.yy.c, which defines a routine yylex(). This file is compiled
and linked with the -lfl library to produce an executable. When the
executable is run, it analyzes its input for occurrences of the regular
expressions. Whenever it finds one, it executes the corresponding C code.
.
The behaviour of Flex has undergone a major change since version
2.5.4a; Flex scanners are now reenterant, you may have multiple
scanners in the same program with differing sets of defaults, and
they play nicer with modern C and C++ compilers. The Flip side is
that Flex no longer conforms to the POSIX lex behaviour, and the
scanners require conforming implementations when flex is used in ANSI
C mode. The package flex-old provides the older behaviour.
.
This product includes software developed by the University of California,
Berkeley and its contributors. The upstream source code can be found at
http://prdownloads.sourceforge.net/lex/flex-2.5.31.tar.bz2?download
The project web page is at http://lex.sf.net/ |