texindex - sort Texinfo index files
texindex [OPTION]... FILE...
Generate a sorted index for each TeX output FILE. Usually FILE... is specified
  as `foo.??' for a document `foo.texi'.
  - -h, --help
- display this help and exit
- -o, --output FILE
- send output to FILE
- --version
- display version information and exit
Email bug reports to bug-texinfo@gnu.org, general questions and discussion to
  help-texinfo@gnu.org. Texinfo home page: http://www.gnu.org/software/texinfo/
Copyright © 2004 Free Software Foundation, Inc. There is NO warranty. You
  may redistribute this software under the terms of the GNU General Public
  License. For more information about these matters, see the files named
  COPYING.
The full documentation for texindex is maintained as a Texinfo manual. If
  the info and texindex programs are properly installed at your
  site, the command
  
  - info texindex
should give you access to the complete manual.