LEX(1)									LEX(1)

NAME
       lex - generator of lexical analysis programs

SYNOPSIS
       lex [ -tvfn ] [ 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
       expressions are found.

       A C source program, 'lex.yy.c' is generated, to be compiled thus:

	      cc lex.yy.c -ll

       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
	      analyzer.

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

       -f     "Faster" compilation: don't bother to pack the resulting tables;
	      limited to small programs.

EXAMPLE
	      lex lexcommands

       would  draw  lex	 instructions from the file lexcommands, and place the
       output in lex.yy.c

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

       is an example of a lex program that would be put	 into  a  lex  command
       file.  This program converts upper case to lower, removes blanks at the
       end of lines, and replaces multiple blanks by single blanks.

SEE ALSO
       yacc(1), sed(1)
       M. E. Lesk and E. Schmidt, LEX - Lexical Analyzer Generator

7th Edition			April 14, 1986				LEX(1)

Vote for polarhome