pg(1) (Directory and File Management Utilities) pg(1)
NAME
pg - file perusal filter for CRTs
SYNOPSIS
pg [ -number ] [ -p string ] [ -cefnrs ] [ +linenumber ] [ +/pattern/
] [ file ... ]
DESCRIPTION
The pg command is a filter that allows the examination of files one
screenful at a time on a CRT. (If no file is specified or if it
encounters the file name -, pg reads from standard input.) Each
screenful is followed by a prompt. If the user types a carriage
return, another page is displayed; other possibilities are listed
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.
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).
-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) 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 (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.
-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 ``:''.
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pg(1) (Directory and File Management Utilities) pg(1)
-r Restricted mode. The shell escape is disallowed. pg will
print an error message but does not exit.
-s Causes pg to 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.
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 that 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>
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.
if Skip i screens of text.
iz Same as <newline> except that i, if present, becomes the new
default number of lines per screenful.
The following perusal commands take no address.
. or ^L
Typing a single period causes the current page of text to be
redisplayed.
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pg(1) (Directory and File Management Utilities) pg(1)
$ Displays 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 ^ notation is useful for Adds 100 terminals
which will not properly handle the ?.
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.
The user of pg 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.
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pg(1) (Directory and File Management Utilities) pg(1)
!command
Command is passed 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, the user 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, because 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).
EXAMPLE
The following command line uses pg to read the system news:
news | pg -p "(Page %d):"
FILES
/usr/share/lib/terminfo/?/*
terminal information database
/tmp/pg* temporary file when input is from a pipe
SEE ALSO
ed(1), grep(1), more(1)
terminfo(4) in the System Administrator's Reference Manual.
NOTES
While waiting for terminal input, pg responds to BREAK, DEL, and
CTRL-\ 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.
The terminal /, ^, or ? may be omitted from the searching commands.
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.
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