# pr

## PROLOG



           This manual page is part of the POSIX Programmer's Manual.  The
           Linux implementation of this interface may differ (consult the
           corresponding Linux manual page for details of Linux behavior), or
           the interface may not be implemented on Linux.
    


## NAME



           pr — print files
    


## SYNOPSIS



           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_...**]**
    


## 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 separated with at least one <blank>.
    


## OPTIONS



           The _pr_ utility shall conform to the Base Definitions volume of
           POSIX.1‐2017, _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> characters in the input shall be
                     expanded into the appropriate number of <space>
                     characters. If any non-digit character, _char_ , is
                     specified, it shall be used as the input <tab>.  If the
                     first character of the **-e** option-argument is a digit,
                     the entire option-argument shall be assumed to be _gap_.
    
           **-f** Use a <form-feed> for new pages, instead of the default
                     behavior that uses a sequence of <newline> characters.
                     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> characters.
    
           **-h** _header_ Use the string _header_ to replace the contents of the
                     _file_ operand in the page header.
    
           **-i[**_char_**][**_gap_**]**
                     In output, replace <space> characters with <tab>
                     characters wherever one or more adjacent <space>
                     characters 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>.  If the first
                     character of the **-i** option-argument is a digit, the
                     entire option-argument shall be assumed to be _gap_.
    
           **-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>
                     characters. 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>
                     characters (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.
    


## 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
           specified, 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 POSIX.1‐2017, _Section 8.2_ ,
                     _Internationalization Variables_ 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> characters or a sequence of <newline>
           characters, 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:
    
               date "+%b %e %H:%M %Y"
    
           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.
    


## STDERR



           The standard error shall be used for diagnostic messages and for
           alerting 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



           A conforming application must protect its first operand, if it
           starts with a <plus-sign>, by preceding it with the **"--"** argument
           that denotes the end of the options. For example, _pr_ +_x_ could be
           interpreted as an invalid page number or a _file_ operand.
    


## 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
           POSIX.1‐2017. 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>
           characters 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 POSIX.1‐2017, as the appropriate vehicle is a message catalog;
           that is, the format should be specified as a ``message''.
    


## FUTURE DIRECTIONS



           None.
    


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