The
cpp
utility is a macro preprocessor used by the
pcc(1)
compiler.
It is used to include header files,
expand macro definitions,
and perform conditional compilation.
The
infile
input file is optional.
If not provided or the file name is
"-"
(dash),
cpp
reads its initial file from standard input.
The
outfile
output file is also optional.
It writes by default to standard output.
The options are as follows:
-?
Show command line usage for
cpp.
-C
Do not discard comments.
-D macro[=value]
Fake a definition at the beginning by using
“#define
macro=value”.
If
value
is not set on command-line, then define it as 1.
-dM
Print list of
“#define”
statements to standard output for all defined macros other than
builtin macros (see below).
The normal results of preprocessing are not output.
-I path
Add
path
to the list of directories containing needed header files.
This may be used to override system include directories
(see
-S
option).
-I
may be specified multiple times.
-i file
Include a file at the beginning by using
“#include
file”.
Inhibit generation of line markers. This is sometimes useful when
running the preprocessor on something other than C code.
-S path
Add
path
to the list of system directories containing needed header files.
The
-S
option may be specified multiple times.
Note:
cpp
does not have a default include directory defined.
-t
Traditional cpp syntax.
Do not define the
__TIME__,
__DATE__,
__STDC__,
and
__STDC_VERSION__
macros.
-U macro
Undefine a macro at the beginning by using
“#undef
macro”.
-V
Verbose debugging output.
-V
can be repeated for further details.
-v
Display version.
Builtin Macros
A few macros are interpreted inside the
cpp
program:
Expands to the date in abbreviated month, day, and year format from
ctime(3)
in quotes.
Expands to the name of the current input file in quotes.
When read from standard input, it expands to
"‹stdin›".
Expands to the line number of the current line containing the macro.
Expands to the constant 1.
This means the compiler conforms to
(also known as
“C90 ”).
Expands to
“199901L”
which indicates that
cpp
supports
(commonly referred to as
“C99 ”).
Expands to the time in hour, minutes, and seconds from
ctime(3)
in quotes.
Also see the
-t
option.
EXIT STATUS
The
cpp
utility exits with one of the following values:
The
cpp
command comes from the original Portable C Compiler by S. C. Johnson,
written in the late 70's.
The code originates from the V6 preprocessor with some additions
from V7 cpp and ansi/c99 support.
A lot of the PCC code was rewritten by Anders Magnusson.
This product includes software developed or owned by Caldera
International, Inc.