lex.1

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.TH LEX 1 "11/27/05" "Heirloom Development Tools" "User Commands"
.SH NAME
lex \- generator of lexical analysis programs
.SH SYNOPSIS
.HP
.ad l
.nh
\fBlex\fR [\fB\-ctvnVew\fR] [\fB\-Q\fR(\fBy\fR|\fBn\fR)]
[\fB\-o\ \fIoutputfile\fR]
[\fIfiles\fR\ ...]
.br
.ad b
.SH DESCRIPTION
.I Lex
generates programs to be used in simple lexical analyis of text.
The input
.I files
(standard input default)
contain regular expressions
to be searched for, and actions written in C to be executed when
expressions are found.
.PP
A C source program, `lex.yy.c' is generated, to be compiled thus:
.IP
cc lex.yy.c \-ll
.LP
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.
.PP
The following 
.I lex
program converts upper case to lower,
removes blanks at the end of lines,
and replaces multiple blanks by single blanks.
.IP ""
.nf
.ta \w'[A\-Z] 'u
%%
[A\-Z]	putchar(yytext[0]+\'a\'\-\'A\');
[ ]+$
[ ]+	putchar(\' \');
.fi
.PP
The options have the following meanings.
.TP
.B \-c
Generate output in the `C' language.
This is the default.
.TP
.B \-e
Generates output that can handle multibyte characters,
with \fIyytext[]\fR being of type \fIunsigned char[]\fR.
This option is an extension.
.TP
.B \-n
Opposite of
.BR \-v ;
.B \-n
is default.
.TP
\fB\-Q\fR(\fBy\fR|\fBn\fR)
With
.BR \-Qy ,
a version identification variable is put into lex.yy.c.
With
.B \-Qn
(the default), no such variable is generated.
.TP
.B \-t
Place the result on the standard output instead of in file
`lex.yy.c'.
.TP
.B \-v
Print a one-line summary of statistics of the generated analyzer.
.TP
.B \-V
Prints version information for
.I lex
on stderr and exits.
.TP
.B \-w
Generates output that can handle multibyte characters,
with \fIyytext[]\fR being of type \fIwchar_t[]\fR.
This option is an extension.
.TP
\fB\-o \fIoutputfile\fR
Use `\fIoutputfile\fR' instead of `lex.yy.c'.
This option is an extension.
.SH "SEE ALSO"
yacc(1)
.br
M. E. Lesk and E. Schmidt,
.I LEX \- Lexical Analyzer Generator