Unix in a Nutshell, 4th Edition

Name

flex

Synopsis

    flex [options] [file]

flex (Fast Lexical Analyzer Generator) is a faster variant of lex. It generates a lexical analysis program (named lex.yy.c) based on the regular expressions and C statements contained in one or more input files. See also lex, bison, yacc, and lex & yacc, cited in the Bibliography.

URL: http://www.gnu.org/software/flex.

Options

-b

Generate backup information to lex.backup.

-B

Generate a batch (noninteractive) scanner.

-c

Ignored; for POSIX compliance only.

-C

Compress scanner tables but do not use equivalence classes or metaequivalence classes.

-Ca

Align tables for memory access and computation. This creates larger tables but gives faster performance.

-Ce

Construct equivalence classes. This creates smaller tables and sacrifices little performance (default).

-Cf

Generate full scanner tables, not compressed.

-CF

Generate faster scanner tables, like -F.

-Cm

Construct metaequivalence classes (default).

-Cr

Bypass use of the standard I/O library; use read(2) system calls instead.

-d

Debug mode.

-f

Create a faster but larger scanner.

-F

Use the fast scanner table representation.

-h, -?, --help

Help summary.

-i

Create a case-insensitive scanner.

-I

Generate an interactive scanner (default).

-l

Maximum lex compatibility.

-L

Suppress #line directives in lex.yy.c.

-n

Ignored; for POSIX compliance only.

-o file

Write output to file instead of lex.yy.c.

-p

Print performance report to standard error.

-P prefix

Change default yy prefix to prefix for all globally ...