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(flex.info)Overview

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Overview
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   This manual describes `flex', a tool for generating programs that
perform pattern-matching on text.  The manual includes both tutorial
and reference sections:

Description
     a brief overview of the tool

Some Simple Examples

Format Of The Input File

Patterns
     the extended regular expressions used by flex

How The Input Is Matched
     the rules for determining what has been matched

Actions
     how to specify what to do when a pattern is matched

The Generated Scanner
     details regarding the scanner that flex produces; how to control
     the input source

Start Conditions
     introducing context into your scanners, and managing
     "mini-scanners"

Multiple Input Buffers
     how to manipulate multiple input sources; how to scan from strings
     instead of files

End-of-file Rules
     special rules for matching the end of the input

Miscellaneous Macros
     a summary of macros available to the actions

Values Available To The User
     a summary of values available to the actions

Interfacing With Yacc
     connecting flex scanners together with yacc parsers

Options
     flex command-line options, and the "%option" directive

Performance Considerations
     how to make your scanner go as fast as possible

Generating C++ Scanners
     the (experimental) facility for generating C++ scanner classes

Incompatibilities With Lex And POSIX
     how flex differs from AT&T lex and the POSIX lex standard

Diagnostics
     those error messages produced by flex (or scanners it generates)
     whose meanings might not be apparent

Files
     files used by flex

Deficiencies / Bugs
     known problems with flex

See Also
     other documentation, related tools

Author
     includes contact information