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<A NAME="PAGENUM-1168"><P>Page 1168</P></A>
<P>If the file contains passwords, it should not be world-readable.
</P>
<P><B>
HISTORY
</B></P>
<P>Written by Rich $alz (rsalz@uunet.uu.net) for InterNetNews.
</P>
<P><B>
SEE ALSO
</B></P>
<P>
innd(8), newsfeeds(5), nnrpd(8), wildmat(3)
</P>
<H3><A NAME="ch05_ 39">
nntpsend.ctl
</A></H3>
<P>nntpsend.ctl—List of sites to feed via
nntpsend.
</P>
<P><B>
DESCRIPTION
</B></P>
<P>The file /news/lib/nntpsend.ctl specifies the default list of sites to be fed by
nntpsend(8).
</P>
<P>Comments begin with a number sign (#) and continue through the end of the line. Blank lines and comments are
ignored. All other lines should consist of four fields separated by a colon.
</P>
<P>The first field is the name of the site as specified in the
newsfeeds(5) file.
</P>
<P>The second field should be the hostname or IP address of the remote site.
</P>
<P>The third field, if non-empty, specifies the default tail truncation size of site's batchfile. This is passed to
shrinkfile as the _s flag. If this field is empty, no truncation is performed.
</P>
<P>The fourth field specifies some default flags passed to
innxmit(8). The flag _a is always given to innxmit and need not
appear here. If no _t timeout flag is given in this field and on the
nntpsend command line, _t 180 will be given to
innxmit.
</P>
<P><B>
HISTORY
</B></P>
<P>Written by Landon Curt Noll (chongo@toad.com) for InterNetNews.
</P>
<P><B>
SEE ALSO
</B></P>
<P>
innxmit(8), newsfeeds(5), nntpsend(8), trunc(1)
</P>
<H3><A NAME="ch05_ 40">
nologin
</A></H3>
<P>nologin—Prevent usual users from logging into the system.
</P>
<P><B>
DESCRIPTION
</B></P>
<P>If the file /etc/nologin exists, login(1) will allow access only to root. Other users will be shown the contents of this file
and their logins refused.
</P>
<P><B>
FILES
</B></P>
<!-- CODE SNIP //-->
<PRE>
/etc/nologin
</PRE>
<!-- END CODE SNIP //-->
<P><B>
SEE ALSO
</B></P>
<P>login(1), shutdown(8)
</P>
<P>Linux, 29 December 1992
</P>
<H3><A NAME="ch05_ 41">
overview.fmt
</A></H3>
<P>overview.fmt—Format of news overview database.
</P>
<A NAME="PAGENUM-1169"><P>Page 1169</P></A>
<P><B>
DESCRIPTION
</B></P>
<P>The file /news/lib/overview.fmt specifies the organization of the news overview database. Blank lines and lines
beginning with a number sign (#) are ignored. The order of lines in this file is important; it determines the order in which the fields
will appear in the database.
</P>
<P>Most lines will consist of an article header name, optionally followed by a colon. A trailing set of lines can have the word
full appear after the colon; this indicates that the header should appear as well as its value.
</P>
<P>If this file is changed, it is usually necessary to rebuild the existing overview database using
expireover(8) after removing all existing overview files.
</P>
<P>The default file, show here, is compatible with Geoff Collyer's
nov package:
</P>
<!-- CODE //-->
<PRE>
Subject:
From:
Date:
Message-ID:
References:
Bytes:
Lines:
## Some newsreaders get better performance if Xref is present
#Xref:full
</PRE>
<!-- END CODE //-->
<P><B>
HISTORY
</B></P>
<P>Written by Rich $alz (rsalz@uunet.uu.net) for InterNetNews. Intended to be compatible with the
nov package written by Geoff Collyer
(geoff@world.std.com).
</P>
<H3><A NAME="ch05_ 42">
passwd
</A></H3>
<P>
passwd—Password file.
</P>
<P><B>
DESCRIPTION
</B></P>
<P>passwd is an ASCII file that contains a list of the system's users and the passwords they must use for access. The password
file should have general read permission (many utilities, such as
ls(1), use it to map user IDs to usernames) but write access
only for the superuser.
</P>
<P>In the good old days, there was no great problem with this general read permission. Everybody could read the
encrypted passwords, but the hardware was too slow to crack a well-chosen password, and moreover, the basic assumption used to
be that of a friendly user community. These days, many people run some version of the shadow password suite, where
/etc/passwd has *s instead of passwords, and the encrypted passwords are in
/etc/shadow, which is readable by root only.
</P>
<P>When you create a new login, leave the password field empty and use
passwd(1) to fill it. A star (*) in the password
field means that this user cannot log in via login(1).
</P>
<P>There is one entry per line, and each line has the format:
</P>
<!-- CODE SNIP //-->
<PRE>
login_name:passwd:UID:GID:user_name:directory:shell
</PRE>
<!-- END CODE SNIP //-->
<P>The field descriptions are
</P>
<TABLE>
<TR><TD>
login_name
</TD><TD>
The name of the user on the system.
</TD></TR><TR><TD>
password
</TD><TD>
The encrypted optional user password.
</TD></TR><TR><TD>
UID
</TD><TD>
The numerical user ID.
</TD></TR><TR><TD>
GID
</TD><TD>
The numerical group ID for this user.
</TD></TR><TR><TD>
user_name
</TD><TD>
The (optional) comment field (often a full username).
</TD></TR><TR><TD>
directory
</TD><TD>
The user's $HOME directory.
</TD></TR><TR><TD>
shell
</TD><TD>
The program to run at login (if empty, use
/bin/sh).
</TD></TR></TABLE>
<A NAME="PAGENUM-1170"><P>Page 1170</P></A>
<P><B>
NOTE
</B></P>
<P>If your root file system is on /dev/ram, you must save a changed password file to your root filesystem floppy before you
shut down the system and check the access rights. If you want to create user groups, their GIDs must be equal and there must
be an entry in /etc/group, or no group will exist.
</P>
<P></B>
FILES
</B></P>
<!-- CODE SNIP //-->
<PRE>
/etc/passwd
</PRE>
<!-- END CODE SNIP //-->
<P><B>
SEE ALSO
</B></P>
<P>
passwd(1), login(1), group(5), shadow(5)
</P>
<P>Linux, 24 July 1993
</P>
<H3><A NAME="ch05_ 43">
passwd.nntp
</A></H3>
<P>passwd.nntp—Passwords for connecting to remote NNTP servers.
</P>
<P><B>
DESCRIPTION
</B></P>
<P>The file /news/lib/passwd.nntp contains host-name-password triplets for use when authenticating client programs to
NNTP servers. This file is normally interpreted by the
NNTPsend-password routine in libinn(3). Blank lines and lines beginning
with a number sign (#) are ignored. All other lines should consist of three or fields separated by colons:
</P>
<!-- CODE SNIP //-->
<PRE>
host:name:password
host:name:password:style
</PRE>
<!-- END CODE SNIP //-->
<P>The first field is the name of a host and is matched in a case-insensitive manner. The second field is a username, and
the third is a password. The optional fourth field specifies the type of authentication to use. The default is
authinfo, which means that NNTP authinfo commands are used to authenticate to the remote host. If either the username or password
are empty, then the related command will not be sent. (The
authinfo command is a common extension to RFC 977.)
For example:
</P>
<!-- CODE SNIP //-->
<PRE>
## UUNET needs a password, MIT doesn't.
mit.edu:bbn::authinfo
uunet.uu.net:bbn:yoyoma:authinfo
</PRE>
<!-- END CODE SNIP //-->
<P>This file should not be world-readable.
</P>
<P><B>
HISTORY
</B></P>
<P>Written by Rich $alz (rsalz@uunet.uu.net) for InterNetNews.
</P>
<P><B>
SEE ALSO
</B></P>
<!-- CODE SNIP //-->
<PRE>
innd(8), libinn(3)
</PRE>
<!-- END CODE SNIP //-->
<H3><A NAME="ch05_ 44">
pbm
</A></H3>
<P>pbm—Portable bitmap file format.
</P>
<P><B>
DESCRIPTION
</B></P>
<P>The portable bitmap format is a lowest common denominator monochrome file format. It was originally designed to make
it reasonable to mail bitmaps between different types of machines using the typical stupid network mailers we have today.
Now it serves as the common language of a large family of bitmap conversion filters. The definition is as follows:
</P>
<P>A "magic number" for identifying the file type. A
pbm file's magic number is the two characters P1.
</P>
<A NAME="PAGENUM-1171"><P>Page 1171</P></A>
<P>Whitespace (blanks, Tabs, CRs, LFs).
</P>
<P>A width, formatted as ASCII characters in decimal.
</P>
<P>Whitespace.
</P>
<P>A height, again in ASCII decimal.
</P>
<P>Whitespace.
</P>
<P>Width * height bits, each either 1 or 0, starting at the top-left corner of the bitmap, proceeding in normal English
reading order.
</P>
<P>The character 1 means black; 0 means white.
</P>
<P>Whitespace in the bits section is ignored.
</P>
<P>Characters from a # to the next end-of-line are ignored (comments).
</P>
<P>No line should be longer than 70 characters.
</P>
<P>Here is an example of a small bitmap in this format:
</P>
<!-- CODE //-->
<PRE>
P1
# feep.pbm
24 7
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 1 1 1 1 0 0 1 1 1 1 0 0 1 1 1 1 0 0 1 1 1 1 0
0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 1 0
0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1 1 0
0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0
0 1 0 0 0 0 0 1 1 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
</PRE>
<!-- END CODE //-->
<P>Programs that read this format should be as lenient as possible, accepting anything that looks remotely like a bitmap.
</P>
<P>There is also a variant on the format, available by setting the
RAWBITS option at compile time. This variant is different in
the following ways:
</P>
<P>The "magic number" is P4 instead of
P1.
</P>
<P>The bits are stored eight per byte, high bit first and low bit last.
</P>
<P>No whitespace is allowed in the bits section, and only a single character of whitespace (typically a newline) is allowed
after the height.
</P>
<P>The files are eight times smaller and many times faster to read and write.
</P>
<P><B>
SEE ALSO
</B></P>
<!-- CODE //-->
<PRE>
atktopbm(1), brushtopbm(1), cmuwmtopbm(1), g3topbm(1), gemtopbm(1), icontopbm(1), macptopbm(1), mgrtopbm(1), pi3topbm(1),
xbmtopbm(1), ybmtopbm(1), pbmto10x(1), pnmtoascii(1), pbmtoatk(1), pbmtobbnbg(1), pbmtocmuwm(1), pbmtoepson(1), pbmtog3(1),
pbmtogem(1), pbmtogo(1), pbmtoicon(1), pbmtolj(1), pbmtomacp(1), pbmtomgr(1), pbmtopi3(1), pbmtoplot(1), pbmtoptx(1),
pbmtox10bm(1), pbmtoxbm(1), pbmtoybm(1), pbmtozinc(1), pbmlife(1), pbmmake(1), pbmmask(1), pbmreduce(1), pbmtext(1),
pbmupc(1), pnm(5), pgm(5), ppm(5)
</PRE>
<!-- END CODE //-->
<P><B>
AUTHOR
</B></P>
<P>Copyright 1989, 1991 by Jef Poskanzer.
</P>
<P>27 September 1991
</P>
<H3><A NAME="ch05_ 45">
pgm
</A></H3>
<P>pgm—Portable graymap file format.
</P>
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