FLEX(1) Programming FLEX(1)

flex - the fast lexical analyser generator

flex [OPTIONS] [FILE]...

Generates programs that perform pattern-matching on text.

-Ca, --align
trade off larger tables for better memory alignment
-Ce, --ecs
construct equivalence classes
do not compress tables; use -f representation
do not compress tables; use -F representation
-Cm, --meta-ecs
construct meta-equivalence classes
-Cr, --read
use read() instead of stdio for scanner input
-f, --full
generate fast, large scanner. Same as -Cfr
-F, --fast
use alternate table representation. Same as -CFr
default compression (same as --ecs --meta-ecs)

-d, --debug
enable debug mode in scanner
-b, --backup
write backing-up information to lex.backup
-p, --perf-report
write performance report to stderr
-s, --nodefault
suppress default rule to ECHO unmatched text
-T, --trace
flex should run in trace mode
-w, --nowarn
do not generate warnings
-v, --verbose
write summary of scanner statistics to stdout
use hexadecimal numbers instead of octal in debug outputs

-o, --outfile=FILE
specify output filename
-S, --skel=FILE
specify skeleton file
-t, --stdout
write scanner on stdout instead of lex.yy.c
name of C++ class
create a C header file in addition to the scanner

--tables-file[=FILE] write tables to FILE

-7, --7bit
generate 7-bit scanner
-8, --8bit
generate 8-bit scanner
-B, --batch
generate batch scanner (opposite of -I)
-i, --case-insensitive
ignore case in patterns
-l, --lex-compat
maximal compatibility with original lex
-X, --posix-compat
maximal compatibility with POSIX lex
-I, --interactive
generate interactive scanner (opposite of -B)
track line count in yylineno

-+, --c++
generate C++ scanner class
#define macro defn (default defn is '1')
-L, --noline
suppress #line directives in scanner
-P, --prefix=STRING
use STRING as prefix instead of "yy"
-R, --reentrant
generate a reentrant C scanner
scanner for bison pure parser.
include yylloc support.
initialize yyin/yyout to stdin/stdout
do not include <unistd.h>
do not generate a particular FUNCTION

do-nothing POSIX option
do-nothing POSIX option


-h, --help
produce this help message
-V, --version
report flex version

The full documentation for flex is maintained as a Texinfo manual. If the info and flex programs are properly installed at your site, the command
info flex

should give you access to the complete manual.

May 2017 The Flex Project