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LEX(1)              UNIX Programmer's Manual               LEX(1)



N\bNA\bAM\bME\bE
    lex - generator of lexical analysis programs

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
    l\ble\bex\bx [ -\b-t\btv\bvf\bfn\bn ] [ file ] ...

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
    _\bL_\be_\bx generates programs to be used in simple lexical analyis
    of text.  The input _\bf_\bi_\bl_\be_\bs (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.

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

    -\b-v\bv   Print a one-line summary of statistics of the generated
         analyzer.

    -\b-n\bn   Opposite of -\b-v\bv; -\b-n\bn is default.

    -\b-f\bf   "Faster" compilation: don't bother to pack the result-
         ing tables; limited to small programs.

E\bEX\bXA\bAM\bMP\bPL\bLE\bE
         lex lexcommands

    would draw _\bl_\be_\bx instructions from the file _\bl_\be_\bx_\bc_\bo_\bm_\bm_\ba_\bn_\bd_\bs, and
    place the output in _\bl_\be_\bx._\by_\by._\bc


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

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





Printed 7/9/88           April 14, 1986                         1






LEX(1)              UNIX Programmer's Manual               LEX(1)



S\bSE\bEE\bE A\bAL\bLS\bSO\bO
    yacc(1), sed(1)
    M. E. Lesk and E. Schmidt, _\bL_\bE_\bX - _\bL_\be_\bx_\bi_\bc_\ba_\bl _\bA_\bn_\ba_\bl_\by_\bz_\be_\br _\bG_\be_\bn_\be_\br_\ba_\bt_\bo_\br




















































Printed 7/9/88           April 14, 1986                         2