ifnames - Extract CPP conditionals from a set of files

       Written by David J. MacKenzie and Paul Eggert.

       Copyright © 2012 Free Software Foundation, Inc.  License GPLv3+/Autoconf: GNU  GPL  version  3  or  later
       <http://gnu.org/licenses/gpl.html>, <http://gnu.org/licenses/exceptions.html>
       This  is  free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent
       permitted by law.

       Scan  all  of  the  C  source  FILES (or the standard input, if none are given) and write to the standard
       output a sorted list of all the identifiers that appear in those files in `#if',  `#elif',  `#ifdef',  or
       `#ifndef'  directives.   Print each identifier on a line, followed by a space-separated list of the files
       in which that identifier occurs.

       -h, --help
              print this help, then exit

       -V, --version
              print version number, then exit

       ifnames - Extract CPP conditionals from a set of files

       Report bugs to <bug-autoconf@gnu.org>.
       GNU Autoconf home page: <http://www.gnu.org/software/autoconf/>.
       General help using GNU software: <http://www.gnu.org/gethelp/>.

autoconf(1), automake(1),  autoreconf(1),  autoupdate(1),  autoheader(1),  autoscan(1),  config.guess(1),
       config.sub(1), ifnames(1), libtool(1).

       The  full  documentation for ifnames is maintained as a Texinfo manual.  If the info and ifnames programs
       are properly installed at your site, the command

              infoifnames

       should give you access to the complete manual.

GNU Autoconf 2.68b.25-19513                        April 2012                                         IFNAMES(1)

ifnames [OPTION]... [FILE]...