Lex Manual Page

NAME

	lex – generator of lexical analysis programs

SYNOPSIS

	lex [ –tvn9 ] [ 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. 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. –9    Adds code to be able to compile through the native C compilers.

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 Research 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.

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