PG(1) SysV PG(1)
NAME
pg - file perusal filter for CRTs
SYNOPSIS
pg [-number] [-p string] [-cefns] [+linenumber] [+/pattern/] [files ...]
DESCRIPTION
The pg program is a filter which allows the examination of files one
screenful at a time on a CRT. If you use a simple dash (-) and/or NULL
arguments in place of a filename, pg reads from the standard input. Each
screenful is followed by a prompt. If you hit a carriage return, pg
displays another page; 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)
database for the terminal type specified by the environment variable
TERM. If TERM is not defined, the terminal type dumb is assumed.
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.
The perusal commands and their defaults are as follows:
(+1)<newline> or <blank> Display one page. The address is specified in
pages.
(+1) l With a relative address, simulate scrolling the
screen, forward or backward, the number of lines
specified. With an absolute address, print a
screenful beginning at the specified line.
(+1) d or ^D Simulate scrolling half a screen forward or
backward.
The following perusal commands take no address.
. or ^L Redisplay the current page of text.
$ Display the last windowful in the file. Use with caution when
the input is a pipe.
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
circumflex (^) notation is useful for Adds 100 terminals which will
not properly handle the question mark (?).
After searching, pg will normally display the line found at the top of
the screen. This can be modified by appending m or b to the search
command to leave the line found in the middle or at the bottom of the
window from now on. The suffix t can be used to restore the original
situation.
You can modify the environment of perusal with the following commands:
in Begin perusing the ith next file in the command line.
The i is an unsigned number, default value is 1.
ip Begin perusing the ith previous file in the command
line. i is an unsigned number, default is 1.
iw Display another window of text. If i is present, set
the window size to i.
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 specified.
h Help by displaying an abbreviated summary of
available commands.
q or Q Quit pg.
!command Pass command to the shell, whose name is taken from
the SHELL environment variable. If this is not
available, the default shell 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, you can hit the
quit key (normally CTRL-\) or the interrupt (break) key. 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 terminal, then pg acts just like cat(1),
except that a header is printed before each file (if there is more than
one).
OPTIONS
-number Use number to specify 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 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 a colon (:).
-c Home the cursor and clear the screen before displaying
each page. This option is ignored if clear_screen is not
defined for this terminal type in the terminfo(4)
database.
-e Refrain from pausing at the end of each file.
-f Inhibit the splitting of lines. (Normally, pg splits
lines longer than screen width, but some character
sequences in the text being displayed (e.g., escape
sequences for underlining) generate undesirable results.)
-n Cause an automatic end of command as soon as a command
letter is entered. (Normally, commands must be terminated
by a <newline> character.)
-s Print all messages and prompts in standout mode (usually
inverse video).
+linenumber Start up at linenumber.
+/pattern/ Start up at the first line containing the regular
expression pattern.
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 BREAK, DEL, and ^ 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 Berkeley's more(1) will find that the z and f commands are
available, and that the terminal /, ^, or ? may be omitted from the
searching commands.
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, terminal settings may not be restored correctly.
FILES
/usr/lib/terminfo/?/* terminal information database
/tmp/pg* temporary file when input is from a pipe
SEE ALSO
ed(1), grep(1). terminfo(4).