|
flex is a tool for generating scanners (programs which
recognize lexical patterns in text).
flex reads the given input files, or its standard input if
no file names are given, 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.
|