.TH CPP 8
.CT 1 prog_c
.SH NAME
cpp \- C language preprocessor
.SH SYNOPSIS
.B /lib/cpp
[
.I option ...
]
[
.I ifile
[
.I ofile
]
]
.SH DESCRIPTION
.I Cpp\^
interprets preprocessor directives
and does macro substitution
for
.IR cc (1)
and other compilers.
The input
.I ifile
and output
.I ofile
default to standard input and standard output respectively.
.PP
The options are:
.TP
.B -P
Do not place line number markings in output.
.TP
.B -C
Do not remove comments.
.TP
.BI -U name\^
.PD 0
.TP
.BI -D name\^
.TP
.BI -D name=def\^
.TP
.BI -I dir\^
Same as in
.IR cc (1).
.B -U
overrides
.BR -D .
.PD
.TP
.B -H
Report all included files on standard error file,.
.TP
.B -M
Attach modification date to file names in line number
directives thus:
.IB file @ modtime,
where modtime is the integer number of seconds since the epoch.
.TP
.B -T
Truncate preprocessor symbols to eight characters.
.TP
.BI -Y dir
Use
.I dir
instead of
.F /usr/include
as the last resort in searching for include files.
.PP
The output file contains processed text sprinkled
with lines that show the original input line numbering:
.IP
.B #
.I linenumber
.L
"\fIifile\fP"
.PP
The input language is as described in the reference,
with a few additions:
.PP
The
.B #
.I linenumber
marks placed in the output are accepted as an alternative
to the official
.B #line
directive.
.PP
These symbols are predefined in various implementations:
.IP
.EX
ibm gcos os tss unix
interdata pdp11 u370 u3b u3b5 vax
RES RT
lint
.EE
.PP
Preprocessor formal parameters are recognized within
quoted strings in the replacement text.
.PP
When comments are removed they are replaced by null strings;
this unofficial feature makes it possible to construct
identifiers by concatenation.
.SH FILES
.TF /usr/include
.TP
.F /usr/include
standard directory for include files
.SH SEE ALSO
B. W. Kernighan and D. M. Ritchie,
.I The C Programming Language,
Prentice-Hall,
1988