NAME

       ifnames - Extract CPP conditionals from a set of files

SYNOPSIS

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

DESCRIPTION

       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

AUTHOR

       Written by David J. MacKenzie and Paul Eggert.

REPORTING BUGS

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

COPYRIGHT

       Copyright © 2021 Free Software Foundation, Inc.  License GPLv3+/Autoconf: GNU  GPL  version  3  or  later
       <https://gnu.org/licenses/gpl.html>, <https://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.

SEE ALSO

       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

              info ifnames

       should give you access to the complete manual.

GNU Autoconf 2.71                                  August 2021                                        IFNAMES(1)