how to add a flat text file to BaseX?

Question

What does it mean "content is not allowed in prolog"? Perhaps the input method needs to be set first? I'm trying to add data to an empty database in Basex with dummy data as below:

thufir@dur:~/flwor/people$ 
thufir@dur:~/flwor/people$ basex
BaseX 9.0.1 [Standalone]
Try 'help' to get more information.
> open people
Database 'people' was opened in 199.0 ms.
> 
> add to people /home/thufir/flwor/people/people.txt
"/home/thufir/flwor/people/people.txt" (Line 2): Content is not allowed in prolog.
> 
> exit
Have a nice day.
thufir@dur:~/flwor/people$ 
thufir@dur:~/flwor/people$ cat people.txt 

a
1
2
3
b
4
5
6
c
7
8
9

thufir@dur:~/flwor/people$ 

I could make it CSV or other, but would like to use just plain text.

Certainly it can be added through the GUI as:

Selecting the file:

Answer 1

Okay, that was perhaps a silly question:

> 
> list
Name                 Resources  Size    Input Path                               
-------------------------------------------------------------------------------
com.w3schools.books  1          6290    https://www.w3schools.com/xml/books.xml  
dummy                1          21119                                            
foo                  1          167152  /home/thufir/basex/foo/foo.fodt          
people               1          4610                                             
text                 1          55302   /home/thufir/Desktop/text.txt            
twitter              45         366800                                           
w3school_data        1          5209    https://www.w3schools.com/xml/note.xml   

7 database(s).
> drop database people
Database 'people' was dropped.
> 
> create database people
Database 'people' created in 79.03 ms.
> 
> open people
Database 'people' was opened in 0.05 ms.
> 
> set parser text
PARSER: text
> 
> add to people /home/thufir/flwor/people/people.txt
Resource(s) added in 9.18 ms.
> 
> list
Name                 Resources  Size    Input Path                               
-------------------------------------------------------------------------------
com.w3schools.books  1          6290    https://www.w3schools.com/xml/books.xml  
dummy                1          21119                                            
foo                  1          167152  /home/thufir/basex/foo/foo.fodt          
people               1          4610                                             
text                 1          55302   /home/thufir/Desktop/text.txt            
twitter              45         366800                                           
w3school_data        1          5209    https://www.w3schools.com/xml/note.xml   

7 database(s).
> 
> exit
Have fun.
thufir@dur:~/flwor/people$