pg(1) General Commands Manual pg(1)
NAME
pg - file perusal filter for soft-copy terminals
SYNOPSIS
number] string] linenumber] pattern] [file ...]
Remarks
and are both used in similar situations (see more(1)). Text highlighting features supported by are not available from However, has some
useful features not provided by
DESCRIPTION
is a text file filter that allows the examination of files one screenful at a time on a soft-copy terminal. If is used as a file argument,
or detects NULL arguments in the comand line, the standard input is used. Each screenful is followed by a prompt. To display a new page,
press Return. Other possibilities are enumerated below.
This command is different from other paginators such as in that it can back up for reviewing something that has already passed. The method
for doing this is explained below.
In order to determine terminal attributes, scans the data base for the terminal type specified by the environment variable (see ter-
minfo(4)). If is not defined, terminal type is assumed.
Options
recognizes the following command line options:
number is an integer specifying the size (in lines) of the window that is to use instead of the default (on a terminal con-
taining 24 lines, the default window size is 23).
Causes to use string as the prompt. If the prompt string contains a the first occurrence of in the prompt is replaced by
the current page number when the prompt is issued. The default prompt string is a colon
Home the cursor and clear the screen before displaying each page.
This option is ignored if is not defined in the data base for this terminal type.
Causes to pause at the end of each file.
Normally, splits lines longer than the screen width, but some sequences of characters in the text being displayed (such as
escape sequences for underlining) generate undesirable results. The option inhibits from splitting lines.
Normally, commands must be terminated by a new-line character.
This option causes an automatic end-of-command as soon as a command letter is entered.
Restricted mode. The shell escape is disallowed.
will print an error message but does not exit.
Causes to print all messages and prompts in standout mode (usually inverse video).
Start display at
linenumber.
Start up at the first line
containing text that matches the regular expression pattern.
looks in the environment variable to preset any flags desired. For example, if you prefer to view files using the mode of operation, the
POSIX-shell command sequence or the C-shell command causes all invocations of including invocations by programs such as and to use this
mode. The command sequence to set up the environment variable is normally placed in the user or file. No form of quoting is provided, so
the string and pattern arguments are limited to single word.
The responses that can be typed when 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 either in pages or lines, depending on the command. A signed address specifies a
point relative to the current page or line; 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.
Perusal commands and their defaults are as follows:
(+1)<newline> or <blank>
Displays one page. The address is specified in pages.
With a relative address,
simulates scrolling the screen, forward or backward, the number of lines specified. With an absolute address prints
a screenful beginning at the specified line.
Simulates scrolling a half-screen forward or backward.
Skip screens of text.
Same as newline except that
, if present, becomes the new default number of lines per screenful.
The following perusal commands take no address:
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.
The following commands are available for searching for text patterns in the text. The Basic Regular Expression syntax (see regexp(5)) is
supported. The terminal or can be omitted from the pattern search commands. Regular expressions must always be terminated by a new-line
character, even if the option is specified.
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.
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 cannot prop-
erly handle the
After searching, normally displays the line found at the top of the screen. This can be modified by appending or to the search command to
leave the line found in the middle or at the bottom of the window from now on. The suffix can be used to restore the original situation.
users can modify the perusal environment with the following commands:
Begin perusing the
ith next file in the command line. The i is an unsigned number, default value is 1.
Begin perusing the
ith previous file in the command line. i is an unsigned number, default is 1.
Display another window of text.
If i is present, set the window size to i.
Save the input in the named file.
Only the current file being perused is saved. The white space between the and filename is optional. This command
must always be terminated by a new-line character, even if the option is specified.
Help by displaying an abbreviated summary of available commands.
Quit pg.
command is passed to the shell, whose name is taken from the environment variable. If this is not available, the default
shell is used. This command must always be terminated by a new-line character, even if the option is specified.
At any time when the output is being sent to the terminal, the user can press the quit key (normally CTRL-), the interrupt (break) key or
the DEL key. This causes to stop sending output, and display the prompt. The user may then enter one of the 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, is functionally equivalent to (see cat(1)), except that a header is printed before each file if
more than one file is specified.
EXTERNAL INFLUENCES
Environment Variables
determines the collating sequence used in evaluating regular expressions.
determines the interpretation of text as single and/or multi-byte characters, and the characters matched by character class expressions in
regular expressions.
determines the language in which messages are displayed.
If or is not specified in the environment or is set to the empty string, the value of is used as a default for each unspecified or empty
variable. If is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of If any internationalization
variable contains an invalid setting, behaves as if all internationalization variables are set to "C". See environ(5).
International Code Set Support
Single- and multi-byte character code sets are supported.
EXAMPLES
To use when reading system news:
WARNINGS
If terminal tabs are not set every eight positions, undesirable results may occur.
When using as a filter with another command that changes the terminal I/O options (such as crypt(1)), terminal settings may not be restored
correctly.
While waiting for terminal input, responds to 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, because an interrupt is
likely to terminate the other commands in the pipeline.
Users of will find that the and commands are available, and that the terminal or can be omitted from the pattern search commands.
FILES
terminal information data base
temporary file when input is from a pipe
SEE ALSO
crypt(1), grep(1), more(1), terminfo(4), environ(5), lang(5), regexp(5).
STANDARDS CONFORMANCE
pg(1)