pg 1 "28 Mar 1995"
Table of contents
pg 1 "28 Mar 1995"
pg - files perusal filter for CRTs
pg
[
-number
] [
-p
string
] [
-cefnrs
] [
+linenumber
]
[
+/pattern/
] [
filename ...
]
SUNWcsu
The
\f3pg
command is a filter that allows the examination
of
filenames
one screenful
at a time on a \s-1CRT\s+1.
If the user types a 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,
\f3pg
scans the
terminfo(4)
data base for the terminal type specified by the
environment variable
\f3TERM\f1.
If
\f3TERM\f1
is not defined,
the terminal type
\f3dumb\f1
is assumed.
-
-number
-
An integer specifying the size (in lines)
of the window that
\f3pg
is to use instead of the default.
(On a terminal containing 24 lines, the default window size is 23).
-
-p string
-
pg
uses
string
as the prompt.
If the prompt string contains a \f3%d, the first occurrence
of \f3%d in the prompt will be replaced
by the current page number when the prompt is issued.
The default prompt string is ``\f3:\f1''.
-
-c
-
Home the cursor and clear the screen before displaying each page.
This option is ignored if
\f3clear_screen\f1
is not defined for this terminal type in the
terminfo(4)
data base.
-
-e
-
pg
does
not
pause at the end of each file.
-
-f
-
Normally,
\f3pg
splits lines longer than the screen width,
but some sequences of characters
in the text being displayed
(for instance, escape sequences for underlining)
generate undesirable results.
The
-f
option inhibits
\f3pg
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.
-
-r
-
Restricted mode.
The shell escape is disallowed.
\f3pg
prints an error message but does not exit.
-
-s
-
pg
prints all messages and prompts in the standard output
mode (usually inverse video).
-
+linenumber
-
Start up at
linenumber.
-
+/pattern/
-
Start up at the first line containing
the regular expression pattern.
The following operands are supported:
-
\f2filename\f1
-
A path name of a text file to be displayed.
If no
filename
is given, or if it is
-, the standard input is read.
The responses that may be typed when
\f3pg
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.
-
\f1(+1) \f3l\f1
-
With a relative address
this causes
\f3pg
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.
-
\f1(+1) \f3d\f1 or \f3^D\f1
-
Simulates scrolling half a screen forward or backward.
-
\f2i\f1\f3f\f1
-
Skip
i
screens of text.
-
\f2i\f1\f3z\f1
-
Same as <\f2newline\f1> except that
i,
if present, becomes the new default number of lines per screenful.
The following perusal commands take no
address.
-
\f3.\f1 or \f3^L\f1
-
Typing a single period causes the current page of text
to be redisplayed.
-
\f3$\f1
-
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 are described on the
regexp(5)
manual page.
They must always be terminated by a
<newline>,
even if the
-n
option is specified.
-
\f2i\f1\f3/\f1\f2pattern\f1\f3/\f1
-
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.
-
\f2i\f1\f3^\f1\f2pattern\f1\f3^\f1
-
-
\f2i\f1\f3?\f1\f2pattern\f1\f3?\f1
-
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,
\f3pg
will normally display the line found at the top of the screen.
This can be modified by appending
\f3m\f1
or
\f3b\f1
to the search
command to leave the line found in the middle or at the bottom of
the window from now on.
The suffix
\f3t\f1
can be used to restore the original situation.
The user of
\f3pg\f1
can modify the environment of perusal with the
following commands:
-
\f2i\f1\f3n\f1
-
Begin perusing the
ith
next file in the command line.
The
i
is an unsigned number, default value is 1.
-
\f2i\f1\f3p\f1
-
Begin perusing the
ith
previous file in the command line.
i
is an unsigned number, default is 1.
-
\f2i\f1\f3w\f1
-
Display another window of text.
If
i
is present, set the window size to
i.
-
\f3s \f1\f2filename\f1
-
Save the input in the named file.
Only the current file being perused is saved.
The white space between the
\f3s\f1
and
filename
is optional.
This command must always be terminated by a
<newline>,
even if the
-n
option is specified.
-
\f3h\f1
-
Help by displaying an abbreviated summary of available commands.
-
\f3q\f1 or \f3Q\f1
-
Quit
\f3pg\f1.
-
\f3!\f1\f2command\f1
-
Command
is passed to the shell, whose name is
taken from the
\f3SHELL\f1
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 \s-1CTRL\s+1-\) or the interrupt (break) key.
This causes
\f3pg
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
\f3pg
acts just like
cat(1),
except that a header is printed before each file (if there is
more than one).
The following command line uses
pg
to read the system news:
\f3example% news | pg -p "(Page %d):"\f1
See
environ(5)
for descriptions of the following environment variables that affect the
execution of
pg:
LC_CTYPE\f1,
LC_MESSAGES\f1,
and
NLSPATH\f1.
The following environment variables affect the execution of
pg:
-
.SB COLUMNS
-
Determine the horizontal screen size.
If unset or
use the value of
the window size, baud rate, or some combination of these,
to indicate the terminal type for the screen size calculation.
-
.SB LINES
-
Determine the number of lines to be displayed on the screen.
If unset or
use the value of
the window size, baud rate, or some combination of these,
to indicate the terminal type for the screen size calculation.
-
.SB SHELL
-
Determine the name of the command interpreter executed for a
!command.
-
.SB TERM
-
Determine terminal attributes.
Optionally attempt to search a system-dependent database,
keyed on the value of the
environment variable.
If no information is available, a terminal incapable of
cursor-addressable movement is assumed.
The following exit values are returned:
-
0
-
Successful completion.
-
>0
-
An error occurred.
-
/tmp/pg*
-
temporary file when input is from a pipe
-
/usr/share/lib/terminfo/?/\(**
-
terminal information database
cat(1),
grep(1),
more(1),
terminfo(4),
environ(5),
regexp(5)
While waiting for terminal input,
\f3pg
responds to
\s-1BREAK\s+1,
\s-1CTRL-C\s+1,
and
\s-1CTRL-\s+1
by terminating execution.
Between prompts, however, these signals interrupt
\f3pg'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
\f3/\f1,
\f3^\f1,
or
\f3?\f1
may be omitted
from the searching commands.
If terminal tabs are not set every eight positions,
undesirable results may occur.
When using
\f3pg
as a filter with another command that changes the terminal I/O options,
terminal settings may not be restored correctly.