index.txt
LEX(1) General Commands Manual LEX(1) NAME lex - generator of lexical analysis programs SYNOPSIS lex [ -tvn ] [ 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. 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)