glenda.party
term% ls -F
term% pwd
$home/manuals/9front/1/lex
term% cat index.txt
LEX(1)                      General Commands Manual                     LEX(1)



NAME
       lex - generator of lexical analysis programs

SYNOPSIS
       lex [ -tvn9 ] [ file ...  ]

DESCRIPTION
       Lex  generates  programs to be used in simple lexical analysis of text.
       The input files (standard input default) contain regular expressions to
       be  searched  for  and actions written in C to be executed when expres‐
       sions are found.

       A C source program, lex.yy.c is generated.   This  program,  when  run,
       copies  unrecognized  portions of the input to the output, and executes
       the associated C action for each regular expression that is recognized.

       The options have the following meanings.

       -t     Place the result on the  standard  output  instead  of  in  file
              lex.yy.c.

       -v     Print  a  one-line  summary  of statistics of the generated ana‐
              lyzer.

       -n     Opposite of -v; -n is default.

       -9     Adds code to be able to compile through the native C compilers.

EXAMPLES
       This program converts upper case to lower, removes blanks at the end of
       lines, and replaces multiple blanks by single blanks.

       %%
       [A-Z]     putchar(yytext[0]+'a'-'A');
       [ ]+$
       [ ]+ putchar(' ');

FILES
       lex.yy.c
              output

       /sys/lib/lex/ncform
              template

SEE ALSO
       yacc(1), sed(1)
       M.  E.  Lesk and E. Schmidt, `LEX—Lexical Analyzer Generator', Unix Re‐
       search System Programmer's Manual, Tenth Edition, Volume 2.

SOURCE
       /sys/src/cmd/lex

BUGS
       Cannot handle UTF.

       The asteroid to kill this dinosaur is still in orbit.



                                                                        LEX(1)