Man1 - flex.1

Table of Contents

NAME

flex - the fast lexical analyser generator

SYNOPSIS

flex [/OPTIONS/] [/FILE/]…

DESCRIPTION

Generates programs that perform pattern-matching on text.

Table Compression:

-Ca, –align
trade off larger tables for better memory alignment
-Ce, –ecs
construct equivalence classes
-Cf
do not compress tables; use -f representation
-CF
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
-Cem
default compression (same as –ecs –meta-ecs)

Debugging:

-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
–hex
use hexadecimal numbers instead of octal in debug outputs

FILES

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

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

Scanner behavior:

-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)
–yylineno
track line count in yylineno

Generated code:

-, *–c*+
generate C++ scanner class
-Dmacro[=/defn/]
#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
–bison-bridge
scanner for bison pure parser.
–bison-locations
include yylloc support.
–stdinit
initialize yyin/yyout to stdin/stdout
–nounistd
do not include <unistd.h>
–noFUNCTION
do not generate a particular FUNCTION

Miscellaneous:

-c
do-nothing POSIX option
-n
do-nothing POSIX option

-?

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

SEE ALSO

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.

Author: dt

Created: 2022-02-22 Tue 17:15