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 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.
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.
LEX(1)
