IFNAMES(1)			  User Commands			      IFNAMES(1)

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', '#ifdef', '#ifndef', '#elif', '#elifdef',
     or '#elifndef' 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,	  or	via    Savannah:
     https://savannah.gnu.org/support/?group=autoconf.

COPYRIGHT
     Copyright (C) 2026 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),  au-
     toscan(1), config.guess(1), config.sub(1), ifnames(1), libtool(1).

     The  full documentation for Autoconf is maintained as a Texinfo manual.  To
     read the manual locally, use the command

	    info autoconf

     You   can	 also	consult	  the	Web   version	of   the    manual    at
     https://gnu.org/software/autoconf/manual/.

GNU Autoconf 2.73		   March 2026			      IFNAMES(1)