PR(P) POSIX Programmer's Manual PR(P)NAMEpr - print files
SYNOPSISpr [+page][-column][-adFmrt][-e[char][ gap]][-h header][-i[char][gap]]
[-l lines][-n[char][width]][-o offset][-s[char]][-w width][-fp]
[file...]
DESCRIPTION
The pr utility is a printing and pagination filter. If multiple input
files are specified, each shall be read, formatted, and written to
standard output. By default, the input shall be separated into 66-line
pages, each with:
* A 5-line header that includes the page number, date, time, and the
pathname of the file
* A 5-line trailer consisting of blank lines
If standard output is associated with a terminal, diagnostic messages
shall be deferred until the pr utility has completed processing.
When options specifying multi-column output are specified, output text
columns shall be of equal width; input lines that do not fit into a
text column shall be truncated. By default, text columns shall be sepa‐
rated with at least one <blank>.
OPTIONS
The pr utility shall conform to the Base Definitions volume of
IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines, except
that: the page option has a '+' delimiter; page and column can be
multi-digit numbers; some of the option-arguments are optional; and
some of the option-arguments cannot be specified as separate arguments
from the preceding option letter. In particular, the -s option does not
allow the option letter to be separated from its argument, and the
options -e, -i, and -n require that both arguments, if present, not be
separated from the option letter.
The following options shall be supported. In the following option
descriptions, column, lines, offset, page, and width are positive deci‐
mal integers; gap is a non-negative decimal integer.
+page Begin output at page number page of the formatted input.
-column
Produce multi-column output that is arranged in column columns
(the default shall be 1) and is written down each column in the
order in which the text is received from the input file. This
option should not be used with -m. The options -e and -i shall
be assumed for multiple text-column output. Whether or not text
columns are produced with identical vertical lengths is unspeci‐
fied, but a text column shall never exceed the length of the
page (see the -l option). When used with -t, use the minimum
number of lines to write the output.
-a Modify the effect of the - column option so that the columns are
filled across the page in a round-robin order (for example, when
column is 2, the first input line heads column 1, the second
heads column 2, the third is the second line in column 1, and so
on).
-d Produce output that is double-spaced; append an extra <newline>
following every <newline> found in the input.
-e[char][gap]
Expand each input <tab> to the next greater column position
specified by the formula n* gap+1, where n is an integer > 0. If
gap is zero or is omitted, it shall default to 8. All <tab>s in
the input shall be expanded into the appropriate number of
<space>s. If any non-digit character, char, is specified, it
shall be used as the input <tab>.
-f Use a <form-feed> for new pages, instead of the default behavior
that uses a sequence of <newline>s. Pause before beginning the
first page if the standard output is associated with a terminal.
-F Use a <form-feed> for new pages, instead of the default behavior
that uses a sequence of <newline>s.
-h header
Use the string header to replace the contents of the file oper‐
and in the page header.
-i[char][gap]
In output, replace multiple <space>s with <tab>s wherever two or
more adjacent <space>s reach column positions gap+1, 2* gap+1,
3* gap+1, and so on. If gap is zero or is omitted, default tab
settings at every eighth column position shall be assumed. If
any non-digit character, char, is specified, it shall be used as
the output <tab>.
-l lines
Override the 66-line default and reset the page length to lines.
If lines is not greater than the sum of both the header and
trailer depths (in lines), the pr utility shall suppress both
the header and trailer, as if the -t option were in effect.
-m Merge files. Standard output shall be formatted so the pr util‐
ity writes one line from each file specified by a file operand,
side by side into text columns of equal fixed widths, in terms
of the number of column positions. Implementations shall sup‐
port merging of at least nine file operands.
-n[char][width]
Provide width-digit line numbering (default for width shall be
5). The number shall occupy the first width column positions of
each text column of default output or each line of -m output. If
char (any non-digit character) is given, it shall be appended to
the line number to separate it from whatever follows (default
for char is a <tab>).
-o offset
Each line of output shall be preceded by offset <space>s. If the
-o option is not specified, the default offset shall be zero.
The space taken is in addition to the output line width (see the
-w option below).
-p Pause before beginning each page if the standard output is
directed to a terminal ( pr shall write an <alert> to standard
error and wait for a <carriage-return> to be read on /dev/tty).
-r Write no diagnostic reports on failure to open files.
-s[char]
Separate text columns by the single character char instead of by
the appropriate number of <space>s (default for char shall be
<tab>).
-t Write neither the five-line identifying header nor the five-line
trailer usually supplied for each page. Quit writing after the
last line of each file without spacing to the end of the page.
-w width
Set the width of the line to width column positions for multiple
text-column output only. If the -w option is not specified and
the -s option is not specified, the default width shall be 72.
If the -w option is not specified and the -s option is speci‐
fied, the default width shall be 512.
For single column output, input lines shall not be truncated.
OPERANDS
The following operand shall be supported:
file A pathname of a file to be written. If no file operands are
specified, or if a file operand is '-' , the standard input
shall be used.
STDIN
The standard input shall be used only if no file operands are speci‐
fied, or if a file operand is '-' . See the INPUT FILES section.
INPUT FILES
The input files shall be text files.
The file /dev/tty shall be used to read responses required by the -p
option.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of pr:
LANG Provide a default value for the internationalization variables
that are unset or null. (See the Base Definitions volume of
IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
ables for the precedence of internationalization variables used
to determine the values of locale categories.)
LC_ALL If set to a non-empty string value, override the values of all
the other internationalization variables.
LC_CTYPE
Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte as
opposed to multi-byte characters in arguments and input files)
and which characters are defined as printable (character class
print). Non-printable characters are still written to standard
output, but are not counted for the purpose for column-width and
line-length calculations.
LC_MESSAGES
Determine the locale that should be used to affect the format
and contents of diagnostic messages written to standard error.
LC_TIME
Determine the format of the date and time for use in writing
header lines.
NLSPATH
Determine the location of message catalogs for the processing of
LC_MESSAGES .
TZ Determine the timezone used to calculate date and time strings
written in header lines. If TZ is unset or null, an unspecified
default timezone shall be used.
ASYNCHRONOUS EVENTS
If pr receives an interrupt while writing to a terminal, it shall flush
all accumulated error messages to the screen before terminating.
STDOUT
The pr utility output shall be a paginated version of the original file
(or files). This pagination shall be accomplished using either <form-
feed>s or a sequence of <newline>s, as controlled by the -F or -f
option. Page headers shall be generated unless the -t option is speci‐
fied. The page headers shall be of the form:
"\n\n%s %s Page %d\n\n\n", <output of date>, <file>, <page number>
In the POSIX locale, the <output of date> field, representing the date
and time of last modification of the input file (or the current date
and time if the input file is standard input), shall be equivalent to
the output of the following command as it would appear if executed at
the given time:
date "+%b %e %H:%M %Y"
without the trailing <newline>, if the page being written is from stan‐
dard input. If the page being written is not from standard input, in
the POSIX locale, the same format shall be used, but the time used
shall be the modification time of the file corresponding to file
instead of the current time. When the LC_TIME locale category is not
set to the POSIX locale, a different format and order of presentation
of this field may be used.
If the standard input is used instead of a file operand, the <file>
field shall be replaced by a null string.
If the -h option is specified, the <file> field shall be replaced by
the header argument.
STDERR
The standard error shall be used for diagnostic messages and for alert‐
ing the terminal when -p is specified.
OUTPUT FILES
None.
EXTENDED DESCRIPTION
None.
EXIT STATUS
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
CONSEQUENCES OF ERRORS
Default.
The following sections are informative.
APPLICATION USAGE
None.
EXAMPLES
1. Print a numbered list of all files in the current directory:
ls -a | pr-n -h "Files in $(pwd)."
2. Print file1 and file2 as a double-spaced, three-column listing
headed by "file list'':
pr-3d -h "file list" file1 file2
3. Write file1 on file2, expanding tabs to columns 10, 19, 28, ...:
pr-e9 -t <file1 >file2
RATIONALE
This utility is one of those that does not follow the Utility Syntax
Guidelines because of its historical origins. The standard developers
could have added new options that obeyed the guidelines (and marked the
old options obsolescent) or devised an entirely new utility; there are
examples of both actions in this volume of IEEE Std 1003.1-2001.
Because of its widespread use by historical applications, the standard
developers decided to exempt this version of pr from many of the guide‐
lines.
Implementations are required to accept option-arguments to the -h, -l,
-o, and -w options whether presented as part of the same argument or as
a separate argument to pr, as suggested by the Utility Syntax Guide‐
lines. The -n and -s options, however, are specified as in historical
practice because they are frequently specified without their optional
arguments. If a <blank> were allowed before the option-argument in
these cases, a file operand could mistakenly be interpreted as an
option-argument in historical applications.
The text about the minimum number of lines in multi-column output was
included to ensure that a best effort is made in balancing the length
of the columns. There are known historical implementations in which,
for example, 60-line files are listed by pr-2 as one column of 56
lines and a second of 4. Although this is not a problem when a full
page with headers and trailers is produced, it would be relatively use‐
less when used with -t.
Historical implementations of the pr utility have differed in the
action taken for the -f option. BSD uses it as described here for the
-F option; System V uses it to change trailing <newline>s on each page
to a <form-feed> and, if standard output is a TTY device, sends an
<alert> to standard error and reads a line from /dev/tty before the
first page. There were strong arguments from both sides of this issue
concerning historical practice and as a result the -F option was added.
XSI-conformant systems support the System V historical actions for the
-f option.
The <output of date> field in the -l format is specified only for the
POSIX locale. As noted, the format can be different in other locales.
No mechanism for defining this is present in this volume of
IEEE Std 1003.1-2001, as the appropriate vehicle is a message catalog;
that is, the format should be specified as a "message".
FUTURE DIRECTIONS
None.
SEE ALSO
expand , lp
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 PR(P)
