pg(1)
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pg Command
file perusal filter for CRT terminals in DG/UX
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SYNTAX
pg [-number] [-p string] [-cefns] [+linenumber] [+/pattern/]
[files...]
DESCRIPTION
The pg command is a filter which allows the examination of files
one screenful at a time on a CRT terminal. (The file name -
and/or NULL arguments indicate that pg should read from the
standard input.) Each screenful is followed by a prompt. If the
user types a carriage return, another page is displayed; other
possibilities are enumerated below.
This command is different from previous paginators in that it
allows you to back up and review something that has already
passed. The method for doing this is explained below.
In order to determine terminal attributes, pg scans the
terminfo(4) data base for the terminal type specified by the
environment variable TERM. If TERM is not defined, the terminal
type dumb is assumed.
The command line options are:
-number
An integer specifying the size (in lines) of the window that
pg is to use instead of the default. (On a terminal
containing 24 lines, the default window size is 23).
-p string
Causes pg to use string as the prompt. If the prompt string
contains a ``%d'', the first occurrence of ``%d'' in the
prompt will be replaced by the current page number when the
prompt is issued. The default prompt string is ``:''.
-c Home the cursor and clear the screen before displaying each
page. This option is ignored if clearscreen is not defined
for your terminal type in the terminfo(4) data base.
-e Causes pg not to pause at the end of each file.
-f Normally, pg splits lines longer than the screen width, but
some sequences of characters in the text being displayed
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(e.g., escape sequences for underlining) generate
undesirable results. The -f option inhibits pg from
splitting lines.
-n Normally, commands must be terminated by a <newline>
character. This option causes an automatic end of command
as soon as a command letter is entered.
-s Causes pg to print all messages and prompts in standout mode
(usually reverse video).
+linenumber
Start up at linenumber.
+/pattern/
Start up at the first line containing the regular expression
pattern.
The responses that may be typed when pg pauses can be divided
into three categories: those causing further perusal, those that
search, and those that modify the perusal environment.
Commands which cause further perusal normally take a preceding
address, an optionally signed number indicating the point from
which further text should be displayed. This address is
interpreted in either pages or lines depending on the command. A
signed address specifies a point relative to the current page or
line, and an unsigned address specifies an address relative to
the beginning of the file. Each command has a default address
that is used if none is provided; it is shown in parentheses
below. Control characters are indicated with a caret, e.g., ^c
for <Control-C> .
The perusal commands and their defaults are as follows:
(+1)<newline> or <space>
This causes one page to be displayed. The address is
specified in pages.
(+1) l
With a relative address this causes pg to simulate scrolling
the screen, forward or backward, the number of lines
specified. With an absolute address this command prints a
screenful beginning at the specified line.
(+1) d or ^D
Simulates scrolling half a screen forward or backward.
The following perusal commands take no address.
. or ^L
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pg(1)
Typing a single period causes the current page of text to be
redisplayed.
$ Displays the last windowful in the file. Use with caution
when the input is a pipe because pg will wait until the
process writing to the pipe is completely finished before
displaying anything.
The following commands are available for searching for text
patterns in the text. The regular expressions described in ed(1)
are available. They must always be terminated by a <newline>,
even if the -n option is specified.
[i]/pattern/
Search forward for the ith (default i=1) occurrence of
pattern. Searching begins immediately after the current
page and continues to the end of the current file, without
wrap-around.
[i]^pattern^
[i]?pattern?
Search backwards for the ith (default i=1) occurrence of
pattern. Searching begins immediately before the current
page and continues to the beginning of the current file,
without wrap-around. The ^ notation is useful for Adds 100
terminals which will not properly handle the ?.
After searching, pg will normally display a screen of text with
the found line at the top of the screen. This can be modified by
appending m or b to the search command to position the found line
in the middle or at the bottom of the window from now on. The
suffix t can be used to restore the original situation.
The user of pg can modify the environment of perusal with the
following commands:
[i]n Begin perusing the ith next file in the command line. The i
is an unsigned number, and its default value is 1.
[i]p Begin perusing the ith previous file in the command line.
The prompt reads Next File. The i is an unsigned number,
and its default is 1.
[i]w Display another window of text. If i is present, set the
window size to i. (The actual size will be i-1).
s filename
Save the input in the named file. Only the current file
being perused is saved. The white space between the s and
filename is optional. This command must always be
terminated by a <newline>, even if the -n option is
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pg(1)
specified.
h Provide help by displaying an abbreviated summary of
available commands.
q or Q
Quit pg.
!command
Command is passed to the shell, whose name is taken from the
SHELL environment variable. If this is not available, the
default shell /bin/sh is used. This command must always be
terminated by a <newline>, even if the -n option is
specified.
At any time when output is being sent to the terminal, the user
can type the quit key (normally control-\) or the interrupt
(break) key to interrupt the display. This causes pg to stop
sending output and display the prompt. The user may then enter
one of the above commands in the normal manner. Unfortunately,
some output is lost when this is done, due to the fact that any
characters waiting in the terminal's output queue are flushed
when the quit signal occurs.
If the standard output is not a tty device, then pg acts just
like cat(1), except that a header is printed before each file if
there is more than one.
EXAMPLE
A sample usage of pg in reading system news would be
news | pg -p "(Page %d):"
NOTES
While waiting for terminal input, pg responds to interrupt and
quit characters by terminating execution. Between prompts,
however, these signals interrupt pg's current task and place the
user in prompt mode. These should be used with caution when
input is being read from a pipe, since an interrupt is likely to
terminate the other commands in the pipeline.
Users of more(1) will find that the z and f commands are
available, and that the terminating /, ^, or ? character may be
omitted from the searching commands.
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pg(1)
FILES
/usr/lib/terminfo/?/*
Terminal information data base
/tmp/pg* Temporary file when input is from a pipe
SEE ALSO
crypt(1), ed(1), more(1), cat(1).
terminfo(4) in the Programmer's Reference for the DG/UX System
BUGS
If terminal tabs are not set every eight positions, undesirable
results may occur.
When using pg as a filter with another command that changes the
terminal I/O options (e.g., crypt(1)), terminal settings may not
be restored correctly.
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