CPP(1)CPP(1)NAMEcpp - C language preprocessor
SYNOPSIScpp [ option ... ] [ ifile [ ofile ] ]
Cpp interprets ANSI C preprocessor directives and does macro substitu‐
tion. The input ifile and output ofile default to standard input and
standard output respectively.
The options are:
-Idir Same as in 8c(1): add dir to the search for directives.
-M Generate no output except a list of include files in a form
suitable for specifying dependencies to mk(1). Use twice to
list files in angle brackets.
-N Turn off default include directories. All must be specified
with -I, or in the environment variable include. Without this
option, /$objtype/include and /sys/include are used as the last
two searched directories for include directives, where $objtype
is read from the environment.
-V Print extra debugging information.
-P Do not insert ``#line'' directives into the output.
-+ Understand C++ comments.
-. Inhibit include search in the source's directory.
-i Print the list of directories searched when #include is found.
Last listed are searched first.
In the absence of the -P option, the processed text output is sprinkled
with lines that show the original input line numbering:
#line linenumber "ifile"
The command reads the environment variable include and adds its (blank-
separated) list of directories to the standard search path for direc‐
tives. They are looked at before any directories specified with -I,
which are looked at before the default directories.
The input language is as described in the ANSI C standard. The stan‐
dard Plan 9 C compilers do not use cpp; they contain their own simple
but adequate preprocessor, so cpp is usually superfluous.
directory for machine-independent include files
directory for machine-dependent include files