.TH CPP 6ACK
.ad
.SH NAME
cpp \- C Pre-Processor
.SH SYNOPSIS
cpp [\-options] [ file ]
.SH DESCRIPTION
.I Cpp
reads a file, expands macros and include
files, and writes an input file for the C compiler.
All output is to standard output.
.br
The following options are supported.
.IP -\fBI\fIdirectory\fR
.br
add this directory to the list of
directories searched for #include "..." and #include <...>
commands.  Note that there is no space between the
"-I" and the directory string.  More than one -I command
is permitted.
.IP -\fBI\fR
end the list of directories to be searched, and also do not look in
default places.
.IP -\fBD\fIname\fR=\fItext\fR
.br
define 
.I name
as a macro with
.I text
as its replacement text.
.IP -\fBD\fIname\fR
the same as -\fBD\fIname\fR=1.
.IP -\fBU\fIname\fR
.br
undefine the macro name
.IR name .
.IP -\fBC\fR
leave comments in. By default, C-comments are deleted.
.IP -\fBP\fR
do not generate line directives
.IP -\fBM\fIn\fR
set maximum identifier length to
.IR n .
.IP -\fBd\fR[\fIfile\fR]
.br
if \fIfile\fR is not given, do not preprocess, but instead generate a list
of makefile dependencies and write them to the standard output.
If \fIfile\fP is given, generate preprocessor output on standard output,
and generate the list of makefile dependencies on file \fIfile\fP.
.IP -\fBxs\fR
when generating makefile dependencies, do not include files from
/usr/include.
.IP -\fBxm\fR
when generating makefile dependencies, generate them in the following format:
.RS
.IP "file.o: file1.h"
.RE
.IP ""
where "file.o" is derived from the source file name. Normally, only a list
of files included is generated.
.IP -\fBundef\fR
.br
this flag is silently ignored, for compatibility with other preprocessors.
.PP
The following names are always available unless undefined:
.IP __FILE__
The input (or #include) file being compiled
(as a quoted string).
.IP __LINE__
The line number being compiled.
.IP __DATE__
The date and time of compilation as
a Unix ctime quoted string (the trailing newline is removed).