LEX(1)                               BSD                                LEX(1)



NAME
     lex - generator of lexical analysis programs

SYNOPSIS
     lex [ -tvfn ] [ file ] ...

DESCRIPTION
     lex generates programs to be used in simple lexical analyis of text.  The
     input files (standard input is the default) contain regular expressions
     to be searched for, and actions written in C to be executed when
     expressions are found.

     lex generates a C source program, lex.yy.c, 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.

OPTIONS
     -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        The opposite of -v; -n is the default.

     -f        Compile faster: don't bother to pack the resulting tables. This
               option is limited to small programs.

EXAMPLE
     To draw lex instructions from the file scanner.l and place the output in
     lex.yy.c, execute the following:

          % lex scanner.l

     The following text is an example of a lex program that would be put into
     a lex command file. This program converts uppercase to lowercase, removes
     blanks at the end of lines, and replaces multiple blanks by single
     blanks.

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


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