Amiga binaries require ixemul.library.
Flex is a tool for generating scanners, programs which recognized 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. 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.