NAME¶
snfetch - fetch articles.
SYNOPSIS¶
snfetch [-
r] [-
t timeout] [-
c depth]
group [
serial [
max]]
DESCRIPTION¶
snfetch expects to read NNTP from file descriptor 6, and write NNTP to
file descriptor 7, which descriptors must have already been open. Articles
retrieved are written to descriptor 1. Each article displayed is separated
from the next by a dot on a line by itself. These articles are NNTP safe, in
the sense that double-dot unquoting is not done, and all lines end in CR-LF.
snfetch expects to begin it's NNTP speech by giving the GROUP command.
The upstream server's greeting must have already been read some other way.
Likewise, when
snfetch is done, it will not send a QUIT command.
The output is suitable for feeding to
snstore.
snfetch always checks the article ID of the prospective article before
retrieving it. If the ID already exists in the ID database, the article will
not be retrieved. Note that this does
not guarantee that all articles
retrieved will be unique.
snfetch does not guarantee to leave the NNTP conversation in a decent
state (there might be more data to read, but
snfetch aborted part way).
You will need to be root or own /var/spool/sn in order to run this program.
It is not safe to direct the output of several
snfetches to the same pipe
descriptor, but a file descriptor is all right.
OPTIONS¶
- -t timeout
- snfetch will wait only timeout seconds (default 180) for
data before giving up, if the server doesn't respond.
- -r
- Output in news batch format instead. All articles will take the #!
rnews form only, even if there is just one article, all lines end in
bare linefeed, and dot-unquoting is performed.
- -c depth
- Employ a command pipeline of depth depth. NNTP command pipelining
is not officially sanctioned, so by default no pipeline is used. However,
a pipeline with a depth greater than 0 will substantally reduce
transaction latency if the server accepts it. A respectable value
for depth might be between 1 and 5.
ARGUMENTS¶
snfetch takes the name of a single newsgroup on its command line. If
serial is given, this is taken to be the first article number on
group on the server to fetch. If
max is specified, this is taken
to be the maximum number of articles to fetch. The first article retrieved may
be after
serial if
max would be violated. If
max is not
specified, there is no limit.
ENVIRONMENT VARIABLES¶
- SNROOT
- If this is set and is not empty, the value is used in place of
/var/spool/sn, the default news spool directory.
FILES¶
- /var/spool/sn/newsgroup/.serial
- If serial is not specified, the starting serial number is taken
from the file /var/spool/sn/newsgroup/.serial. This defaults
to 0 if the file can't be read.
- /var/spool/sn/newsgroup/.serial.tmp
- If snfetch exits with success (0), the new serial is written
into this file. The original file /var/spool/sn/newsgroup/.serial
is readonly by snfetch.
- /var/spool/sn/newsgroup/.max
- If max is not specified on the command line, max is read
from this file. If the file cannot be read or does not exist, there is no
limit.
EXIT CODES¶
snfetch exits 1 on usage error, 2 on system failure, 3 on protocol error,
4 on read timeout, and 0 on success.
SEE ALSO¶
snstore (8), snget (8)