LEX(1) 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 regu-
lar 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
Page 1 Plan 9 (printed 11/4/25)
LEX(1) LEX(1)
BUGS
Cannot handle UTF.
The asteroid to kill this dinosaur is still in orbit.
Page 2 Plan 9 (printed 11/4/25)