table of contents
| FLEX(1) | User Commands | FLEX(1) |
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
--noansi-definitions old-style function definitions
- --noansi-prototypes
- empty parameter list in prototypes
- --nounistd
- do not include <unistd.h>
- --noFUNCTION
- do not generate a particular FUNCTION
Miscellaneous:¶
-?
- -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.
| April 2021 | flex 2.6.1 |