Most Unix-based newsreaders parse and extract your newsgroup
information from a .newsrc file. This file contains an
entry for each newsgroup, with the name of the group and a comma-separated
list of article numbers from 1 to the current article. The first entry
in the list shows articles that have been read; the remaining entries
list unread articles. Each entry also
has a colon (
:) following the name if you
are subscribed to that newsgroup
or an exclamation point (
!) if you are currently unsubscribed.
In order for you to read a newsgroup, your newsreader needs to be connected to an NNTP server. The newsreader then checks the .newsrc entry for that newsgroup to determine which articles you haven't yet read, and displays the first unread article. You can then read the articles sequentially or select which articles you want to read. When you "catch-up" a newsgroup by marking all the articles as "read," or when you exit from the newsreader program, your .newsrc file is updated to reflect your activity during that session.
The News::Newsrc module provides methods for managing your .newsrc file. Some of the functions it provides include letting you add, remove, or reorder newsgroups; subscribe to or unsubscribe from newsgroups; and mark articles as read or unmark them. Unless you tell it to rearrange the order of the newsgroups in .newsrc, News::Newsrc leaves the order unchanged.