My title is the question.I'm looking at a script which makes a popen call to debconf-communicate with a cli argument -fnoninteractive.What does the -fnoninteractive do?
What does -fnoninteractive mean in a call to debconf-communicate?
debconf
The -f option specifies a frontend.  This is documented in the debconf-communicate --help message:  -f,  --frontend               Specify debconf frontend to use.So, -fnoninteractive specifies the noninteractive frontend.  The behavior of this frontend is explained in man 7 debconf (or the online version here) which reads:   noninteractive          This is the anti-frontend. It never interacts with you  at  all,          and  makes  the  default  answers  be used for all questions. It          might mail error messages to root, but thats it;  otherwise  it          is  completely  silent  and  unobtrusive, a perfect frontend for          automatic installs.   If  you  are  using  this  front-end,  and          require  non-default  answers  to  questions,  you  will need to          preseed  the  debconf  database;  see  the  section   below   on          Unattended Package Installation for more details.In other words, -fnoninteractive means what is says: the program doesn't try to interact with you, making it suitable for automated scripts.If you want still more detail, the perl source code for noninteractive and the other frontends is in /usr/share/perl5/Debconf/Element.