Originální popis anglicky:
pr - print files
Návod, kniha: POSIX Programmer's Manual
pr
[+page][-column][-adFmrt
][-e[char][
gap]][-h
header][-i[char
][gap]]
[-l
lines][-n[char][width]][-o
offset][-s[char]][-w
width][-fp]
[file...]
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 separated with at least one
<blank>.
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 decimal 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 unspecified,
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 operand 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 utility 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 support
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 specified, the default width shall be 512.
For single column output, input lines shall not be truncated.
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.
The standard input shall be used only if no
file operands are specified,
or if a
file operand is
'-' . See the INPUT FILES section.
The input files shall be text files.
The file
/dev/tty shall be used to read responses required by the
-p option.
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
Variables 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.
If
pr receives an interrupt while writing to a terminal, it shall flush
all accumulated error messages to the screen before terminating.
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 specified. 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:
without the trailing <newline>, if the page being written is from standard
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.
The standard error shall be used for diagnostic messages and for alerting the
terminal when
-p is specified.
None.
None.
The following exit values shall be returned:
- 0
- Successful completion.
- >0
- An error occurred.
Default.
The following sections are informative.
None.
- 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, ...:
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 guidelines.
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 Guidelines. 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 useless 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".
None.
expand ,
lp
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
.
