NAME
ifdef - remove #ifdefs from a file
SYNOPSIS
ifdef [-t] [-dsymbol] [-Dsymbol] [-Usymbol] [-Isymbol]
[file]
OPTIONS
-D Define symbol permanently
-I Ignore symbol
-U Undefine symbol permanently
-d Define symbol. It may be #undef'ed later
-t Produce a table of the symbols on stdout
EXAMPLES
ifdef -DUNIX file.c >newfile.c
# Define UNIX
ifdef -D_MINIX -UDOS <x.c >y.c
# Define
DESCRIPTION
Ifdef allows conditional code [ #ifdef ... #endif ] to be
selectively removed from C files, but at the same time leav-
ing all other C preprocessor commands intact such as
#define, #include etc. Input to ifdef is either the file
named as the last argument, or stdin if no file is named.
Output goes to stdout.
Symbols may be defined with the -d or -D flags just like
cpp, except that the latter option ignores subsequent
#undefs. It is not permitted to give values to symbols.
Similarly, -U undefines a symbol and ignores subsequent
#definess. Symbols defined with -I are ignored; any #ifdef
using an ignored symbol will be left intact.