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Command: ifdef | Section: 1 | Source: MINIX | File: ifdef.1
IFDEF(1) General Commands Manual IFDEF(1)
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 _MINIX, undefine DOS
DESCRIPTION
Ifdef allows conditional code [ #ifdef ... #endif ] to be selectively
removed from C files, but at the same time leaving all other C pre-
processor 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 ig-
nores subsequent #definess. Symbols defined with -I are ignored; any
#ifdef using an ignored symbol will be left intact.
IFDEF(1)