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lex(1) [ultrix man page]

lex(1)							      General Commands Manual							    lex(1)

       lex - generate lexical analyzer

       lex [-tvfn] file...

       The  command  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.  It is compiled using the following command line:
       cc lex.yy.c -ll
       This program copies unrecognized portions of the input to the output, and executes the associated C action for each regular expression that
       is recognized.

       -f   Runs a faster compilation (does not pack resulting tables).  This is limited to small programs.

       -n   Prints no summary information (default option).

       -t   Writes to standard output instead of to file

       -v   Prints one-line summary of generated statistics.

       In the following example, the command
       lex lexcommands
       draws instructions from the file lexcommands, and places the output in lex.yy.c.  The command
       [A-Z]	 putchar(yytext[0]+'a'-'A');
       [ ]+$
       [ ]+ putchar(' ');

       is  an example of a program that would be put into a 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
       sed(1), yacc(1)
       "LEX - Lexical Analyzer Generator", Supplementary Documents, Volume 2: Programmer


Check Out this Related Man Page

yacc(1) 						      General Commands Manual							   yacc(1)

       yacc - yet another compiler-compiler

       yacc [-vd] grammar

       The command converts a context-free grammar into a set of tables for a simple automaton which executes an left recursive parsing algorithm.
       The grammar may be ambiguous; specified precedence rules are used to break ambiguities.

       The output file, must be compiled by the C compiler to produce a program yyparse.  This program must be loaded with  the  lexical  analyzer
       program,  yylex, as well as main and yyerror, an error handling routine.  These routines must be supplied by the user; is useful for creat-
       ing lexical analyzers usable by

       -d Writes all define statements to file.  This allows source files other than to access the token codes.

       -v Writes description of parsing tables and report of grammatical conflicts to file.

       The number of reduce-reduce and shift-reduce conflicts is reported on the standard output; a more detailed report is  found  in	the  Simi-
       larly, if some rules are not reachable from the start symbol, this is also reported.

       Because file names are fixed, at most one process can be active in a given directory at a time.

       y.output		   defines for token names
       yacc.tmp, yacc.acts temporary files

See Also
       "YACC - Yet Another Compiler Compiler" ULTRIX Supplementary Documents Vol. II:Programmer

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