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Generating a Directory Listing

Not all web servers can generate directory listings (Static Sites), or if they
do (like apache, and nginx) the directory listing has been disabled at the
system level, and users are not allowed to re-enable.

Directory Listings Best Practices...
  https://community.wd.com/t/58397

  Which lists points such as...
  * breadcrumb path for the current directory, link to all parent directories
  * custom header and footer for each
  * folder sizes
  * thumbnail previews (images, videos, pdf's)
  * directory tree
  * select and download multiple files

So far I have NOT found a simple but practical directory index file generator,
without all the extranious features of templating found in full SSG's.

Here are some ways of generating directory listings...

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Apache

If enabled Apache can generate quite good directory listings...
Complete with headers footers, file type icons, and individual file comments.

I have yet to find any altuernative that provides the equivelent generation,
and would love to see something that can generate this outside Apache.

I have actually used a local apache webserver to generate index files which
I then include in the file upload to a static web site.  In fact you're
probably using that sight right now, (the "Tower of Computational Sorcery")!

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To enable (if allowed), you need to create a ".htaccess" file (make sure it is
readable) with the options line...
  Options Indexes

However to go further you may also want to set the following options
to generate a 'fancy' listing, with out excess 'size/date' information.

  IndexOptions FancyIndexing IconWidth=12 NameWidth=*
  IndexOptions SuppressColumnSorting SuppressLastModified SuppressSize

You can specifically remove files from the directory listing using...

  IndexIgnore .* *.gif do_not_list_this_file.txt

NOTE: 'IndexIgnore' will automatically ignore files or directories that are not
readable or accessible.  But does not prevent the files from being accessed,
for example the 'GIF' images in the above ignore are not listed but can still
be used by other pages, including in the directory listing itself (see below).

The FancyIndexing also has 'filetype' icons which normally comes from the
server's "/icon" aliases image directory, and which are normally defined in the
apache "autoindex.conf" file.  Of course a remote static site will not have
these, so you will want to set them to images you do upload.

For example the default settings to use the "text.gif" image for text files
are..

   # By mime filetype
   AddIconByType (TXT,/icons/text.gif) text/*

   # By filename suffix
   AddIcon /icons/text.gif .txt

You can use these in your ".htaccess" file too.

You can also specify the mime types for specific files, or suffixes, which
also helps when a client tries to download that file!  For example I have...

   DefaultIcon  /images/Symbols/scroll.gif
   AddIconByType (TXT,/images/Symbols/scroll.gif) text/*
   AddType text/plain .txt
   AddType text/plain .notes
   AddType text/plain .info
   AddType text/plain .txt

Next you can specify the HTML you want to appear before and after the
directory listing (which can also specify document colours, and CSS settings
for the directory..

  HeaderName ".header.html"
  ReadmeName ".footer.html"

As the name implies 'ReadmeName' nowmally points to a README file, which by
default is output after the directory listing.

Finally Apache lets you add a text decription of the file being listed,
if it is listed...

  AddDescription "Generating Directory Listing Indexes"    dir_listings.txt

As you are using a Apache ".htaccess" (if you are not generating and uploading)
you may also like to improve your security by looking at this document.

   https://antofthy.gitlab.io/info/www/passwd_protect_101.txt

This includes techniques on how to prevent some files from being served (and
also remove them from directory listings)

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Simple HTML Directory Listing Generators

The Linux "tree" command can generate a simple listing with some colors...
And can even do it recursivally!

  tree -H '.' -L 1 -T "Listing" --noreport --charset utf-8

To remove sub-directories add:  --prune
Only list 'zip files' use:      -p '*.zip'
Remove the 'tree' credits:      tree ... | sed -e '/<hr>/,+7d'

It does not however let you easily ass headers and footers.

A example "tree" command is given in...
  https://stackoverflow.com/a/46383157/701532

And a recursive script
  https://gist.github.com/glowinthedark/625eb4caeca12c5aa52778a3b4b0adb4

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