trn.1

早期freebsd实现

.IR more (1)
program does this.)
This feature works only if you have the requisite termcap
capabilities.
The switch has no effect unless the
.B \-e
switch is set.
.TP 5
.B \-m=<mode>
enables the marking of the last line of the previous page
printed, to help the user see where to continue reading.
This is most helpful when less than a full page is going to be displayed.
It may also be used in conjunction with the
.B \-e
switch, in which case the page is erased, and the first line (which is
the last line of the previous page) is highlighted.
If
.B \-m=s
is specified, the standout mode will be used, but if
.B \-m=u
is specified, underlining will be used.
If neither
.B =s
or
.B =u
is specified, standout is the default.
Use
.B +m
to disable highlighting.
.TP 5
.B \-M
forces mailbox format in creating new save files.
Ordinarily you are asked which format you want.
.TP 5
.B \-N
forces normal (non-mailbox) format in creating new save files.
Ordinarily you are asked which format you want.
.TP 5
.B \-o
will act like old versions of trn and not junk cross-referenced articles
when using thread commands to junk articles in the current group (such as
the selector's \*(L'X\*(R' command).
.TP 5
.B \-O<mode>{<order>}
specifies the selector's mode and (optionally) the sort order.
The modes are \*(L'a\*(R'rticle, \*(L's\*(R'ubject, or \*(L't\*(R'hread.
The orders are \*(L'd\*(R'ate, \*(L's\*(R'ubject, \*(L'a\*(R'uthor,
article \*(L'c\*(R'ount per group, or subject-date \*(L'g\*(R'roups.
The order can be capitalized to reverse the indicated order.
For example, to choose the article selector in subject order specify
\*(L"-Oas\*(R".
.TP 5
.B \-p
tells trn to auto-select your postings and their replies as it encounters them
in the various groups you read.
.TP 5
.B \-q
bypasses the automatic check for new newsgroups when starting 
.IR trn .
.TP 5
.B \-r
causes
.I trn
to restart in the last newsgroup read during a previous session with
.IR trn .
It is equivalent to starting up normally and then getting to the newsgroup
with a g command.
.TP 5
.B \-s
with no argument suppresses the initial listing of newsgroups with unread
news, whether
.B \-c
is specified or not.
Thus
.B \-c
and
.B \-s
can be used together to test \*(L"silently\*(R" the status of news from
within your
.I .login
file.
If
.B \-s
is followed by a number, the initial listing is suppressed after that many
lines have been listed.
Presuming that you have your
.I .newsrc
sorted into order of interest,
.B \-s5
will tell you the 5 most interesting newsgroups that have unread news.
This is also a nice feature to use in your
.I .login
file, since it not only tells you whether there is unread news, but also how
important the unread news is, without having to wade through the entire
list of unread newsgroups.
If no 
.B \-s
switch is given 
.B \-s5
is assumed, so just putting \*(L"rn \-c\*(R"
into your
\&.login file is fine.
.TP 5
.B \-S<number>
causes
.I trn
to enter subject search mode (^N) automatically whenever an unthreaded
newsgroup is
started up with <number> unread articles or more.
Additionally, it causes any \*(L'n\*(R' typed while in subject search mode
to be interpreted as \*(L'^N\*(R' instead.
(To get back out of subject search mode, the best command is probably
\&\*(L'^\*(R'.)
If <number> is omitted, 3 is assumed.
.TP 5
.B \-t
puts
.I trn
into terse mode.
This is more cryptic but useful for low baud rates.
(Note that your system administrator may have compiled
.I trn
with either verbose or terse messages only to save memory.)
You may wish to use the baud-rate switch modifier below to enable terse mode
only at lower baud rates.
.TP 5
.B \-T
allows you to type ahead of rn.
Ordinarily rn will eat typeahead to prevent your autorepeating space bar from
doing a very frustrating thing when you accidentally hold it down.
If you don't have a repeating space bar, or you are working at low baud
rate, you can set this switch to prevent this behavior.
You may wish to use the baud-rate switch modifier below to disable typeahead
only at lower baud rates.
.TP 5
.B \-u
sets the unbroken-subject-line mode in the selector, which simply truncates
subjects that are too long instead of dumping the middle portion prior to
the last two words of the subject.
.TP 5
.B \-v
sets verification mode for commands.
When set, the command being executed is displayed to give some feedback that
the key has actually been typed.
Useful when the system is heavily loaded and you give a command that takes
a while to start up.
.TP 5
.B \-x{<number>}{<list>}
Enable the extended (threaded) features of
.I trn
beyond the
.I rn
compatibility mode
(this may be the default on your system, use +x if you yearn for the good
ol' days).
The <number> is the maximum number of article-tree lines (from 0 to 11)
you want displayed in your header.
Use the <list> to choose which thread selector styles you like
(\*(L's\*(R'hort, \*(L'm\*(R'edium, or \*(L'l\*(R'ong), and in what order
they are selected with the \*(L'L\*(R' command.
For example, use
.B \-xms
to start with the medium display mode and only switch between it and
the short mode.
You can omit either or both of the parameters, in which case a default of
.B \-x6lms
is assumed.
.TP 5
.B \-X{<number>}{<commands>}
If you like using the selector, you'll probably want to use this
option to make the selector command (+) the default when a newsgroup
is started up with at least <number> unread articles.
(Your installer may have chosen to make -X1 the default on your system.)
It is also used to select which commands you want to be the defaults while
using the thread selector.
For example,
.B \-X2XD
will make the thread selector the default command for entering a newsgroup
with at least 2 unread articles, and set the default command for the LAST
page of the thread selector to be the
.B X
command and the default command for all other pages to be the
.B D
command.
Either or both parameters can be omitted, as well as the second default
command (e.\|g.
.B \-XX
would change the default newsgroup entry to use the selector and the default
command for the last page of the selector to be \*(L'X\*(R').
The default is
.B \-X1Z>
if just
.B \-X
is specified.
To set the default selector commands without having \*(L'+\*(R' be the
default entry into a newsgroup, specify a high number, like 9999.
.TP 5
.B \-/
sets SAVEDIR to \*(L"%p/%c\*(R" and SAVENAME to \*(L"%a\*(R", which means
that by default articles are saved in a subdirectory of your private news
directory corresponding to the name of the the current newsgroup, with the
filename being the article number.
.B +/
sets SAVEDIR to \*(L"%p\*(R" and SAVENAME to \*(L"%^C\*(R", which by
default saves articles directly to your private news directory, with the
filename being the name of the current newsgroup, first letter capitalized.
(Either
.B +/
or
.B \-/
may be default on your system, depending on the feelings of your news
administrator when he, she or it installed
.IR trn .)
You may, of course, explicitly set SAVEDIR and SAVENAME to other
values \*(-- see discussion in the environment section.
.PP
Any switch may be selectively applied according to the current baud-rate.
Simply prefix the switch with +speed to apply the switch at that speed or
greater, and \%\-speed to apply the switch at that speed or less.
Examples: \%\-1200\-hposted suppresses the Posted line at 1200 baud or less;
\%+9600\-m enables marking at 9600 baud or more.
You can apply the modifier recursively to itself also: \%+300\-1200\-t sets
terse mode from 300 to 1200 baud.
.PP
Similarly, switches may be selected based on terminal type:
.Sp
	\-=vt100+T		set +T on vt100
.br
	\-=tvi920\-ETERM=mytvi	get a special termcap entry
.br
	\-=tvi920\-ERNMACRO=%./.rnmac.tvi
.br
				set up special key-mappings
.br
	+=paper\-v		set verify mode if not hardcopy
.PP
Some switch arguments, such as environment variable values, may require
spaces in them.
Such spaces should be quoted via ", ', or \e in the conventional fashion,
even when passed via TRNINIT or the & command.
.Sh "Regular Expressions"
The patterns used in article searching are regular expressions such as
those used by
.IR ed (1).
In addition, \ew matches an alphanumeric character and \eW a non-alphanumeric.
Word boundaries may be matched by \eb, and non-boundaries by \eB.
The bracketing construct \e(\ ...\ \e) may also be used, and \edigit matches
the digit'th substring, where digit can range from 1 to 9.
\e0 matches whatever the last bracket match matched.
Up to 10 alternatives may given in a pattern, separated by \e|, with the
caveat that \e(\ ...\ \e|\ ...\ \e) is illegal.
.Sh "Interpretation and Interpolation"
Many of the strings that
.I trn
handles are subject to interpretations of several types.
Under filename expansion, an initial \*(L"~/\*(R" is translated to the name
of your home directory, and \*(L"~name\*(R" is translated to the login
directory for the user specified.
Filename expansion will also expand an initial environment variable, and
also does the backslash, caret and percent expansion mentioned below.
.PP
All interpreted strings go through backslash, caret and percent
interpretation.
The backslash escapes are the normal ones (such as \en, \et, \e033, etc.).
The caret escapes indicate control codes (such as ^i, ^l, etc.).
If you wish to pass through a backslash or a caret it must be escaped with
a backslash.
The special percent escapes are similar to printf percent escapes.
These cause the substitution of various run-time values into the string.
The following are currently recognized:
.Ip %a 8
Current article number.
.Ip %A 8
Full name of current article (%P/%c/%a).
.Ip %b 8
Destination of last save command, often a mailbox.
.Ip %B 8
The byte offset to the beginning of the part of the article to be saved,
set by the save command.
The \*(L's\*(R' and \*(L'S\*(R' commands set it to 0, and the \*(L'w\*(R'
and \*(L'W\*(R' commands set it to the byte offset of the body of the article.
.Ip %c 8
Current newsgroup, directory form.
.Ip %C 8
Current newsgroup, dot form.
.Ip %d 8
Full name of newsgroup directory (%P/%c).
.Ip %D 8
\*(L"Distribution:\*(R" line from the current article.
.Ip %e 8
The last command executed to extract data from an article.
.Ip %E 8
The last directory where an extracted file went.
.Ip %f 8
\*(L"From:\*(R" line from the current article, or the \*(L"Reply-To:\*(R"
line if there is one.
This differs from %t in that comments (such as the full name) are not
stripped out with %f.
.Ip %F 8
\*(L"Newsgroups:\*(R" line for a new article, constructed from
\*(L"Newsgroups:\*(R" and \*(L"Followup-To:\*(R" lines of current article.
.Ip %h 8
Name of the header file to pass to the mail or news poster,
containing all the information that the poster program needs in the
form of a message header.
It may also contain a copy of the current article.
The format of the header file is controlled by the MAILHEADER and NEWSHEADER
environment variables.
.Ip %H 8
Host name (your machine's name).
.Ip %i 8
\*(L"Message-I.D.:\*(R" line from the current article, with <> guaranteed.
.Ip %I 8
The reference indication mark (see the
.B \-F
switch.)
.Ip %l 8
The news administrator's login name, if any.
.Ip %L 8
Login name (yours).
.Ip %m 8
The current mode of
.I trn,
for use in conditional macros.
.Sp
.nf
	i	Initializing.
	n	Newsgroup-selection level.
	f	end (Finis) of newsgroup-selection level.
	t	the Thread/subject/article selector.
	a	Article level (What next?).
	e	End of the article level.
	p	Pager level (MORE prompt).
	u	Set-unread prompt.
	d	selector moDe prompt.
	o	selector Order prompt.
	m	Memorize thread command prompt.
	r	memoRize subject command prompt.
	k	processing memorized (KILL file) commands.
	A	Add this newsgroup?
	B	aBandon confirmation.
	C	Catchup confirmation.
	D	Delete bogus newsgroups?
	F	Is follow-up a new topic?
	M	Use mailbox format?
	R	Resubscribe to this newsgroup?
.fi
.Sp
Note