When a web server does not allow directory listing of files inside, for whatever reasons. tree command can be used to generate a simple index.html file, that lists the contents of your directory, which can then be used to browse the contents of your directory from web server.

tree -H '.' -L 1 -P "*.html" --noreport --prune -T "Doc title" > index.html

Above command will generate a simple index.html file which contains the link to all .html files in your current directory.

• -H '.' - enables html output with current directory as the base path.
• -L 1 - limit directory listing to 1 level deep.
• -P "*.html" - list only files/directories matching “.html” pattern
• --noreport - omits file and directory stats at the end of report
• --prune - removes empty directories from listed in the output.
• -T "Title" - sets the document and H1 header to ‘Title’ instead of default string.

tree command also supports JSON and XML outputs using -J and -X options respectively.

References:

1. stackoverflow.com
2. man tree