<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">% 
% \iffalse
%&lt;*driver&gt;
\documentclass{tclldoc}
\PageIndex\CodelineNumbered
\IndexPrologue{%
   \section*{Index}%
   All numbers in this index are page numbers.
   Underlined entries refer to places where the item in
   question is defined.%
}
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\begin{document}
\DocInput{pdf.dtx}
\end{document}
%&lt;/driver&gt;
% \fi
% 
% \title{A simple PDF writer in \Tcllogo}
% \author{Lars Hellstr\"om}
% \maketitle
% 
% \begin{abstract}
%   This file contains some basic routines that allow a \Tcllogo\ 
%   script to write PDF files.
% \end{abstract}
% 
% \tableofcontents
% 
% \section{PDF files and objects}
% 
% A Portable Document Format (PDF) file is, when compared with for example 
% a PostScript file or HTML file, a rather disorganised document. This 
% is because at the basic level, a PDF file is a heap rather than a 
% text; it \emph{can} be ``disorganised'' since its logical structure 
% is based on cross-referencing rather than on sequentiality. The first 
% step is therefore to provide support for writing well-formed heaps.
% 
% \changes{0.0}{2003/01/02}{Initial version. (LH)}
% 
% \begin{tcl}
%&lt;*pkg&gt;
package require Tcl 8.1
package provide writepdf 0.1
namespace eval pdf {}
% \end{tcl}
% \setnamespace{pdf}
% 
% 
% \subsection{Building objects}
% 
% The independent units in a PDF file are called objects. An 
% \emph{object} is essentially a value (which includes a type). The 
% procedures below construct strings of PDF code that encode objects of 
% various types. The strings returned are generally such that one must 
% insert whitespace between two such strings if the data is to be 
% properly encoded. The strings may contain newlines if some building 
% routine thinks the lines should otherwise be too long.
% 
% \begin{proc}{boolean_obj}
%   The |boolean_obj| procedure returns a boolean object, corresponding 
%   to the string passed as its only argument. Most of it is about 
%   parsing this string: \texttt{true}, \texttt{yes}, \texttt{on}, and 
%   nonzero numbers are interpreted as boolean true, whereas 
%   \texttt{false}, \texttt{no}, \texttt{off}, and the zero number is 
%   interpreted as boolean false. The matching is case-insensitive.
%   \begin{tcl}
proc pdf::boolean_obj {value} {
   switch -nocase -- $value {
     true - yes - on {return true}
     false - no - off {return false}
     default {
       if {$value} then {return true} else {return false}
     }
   }
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{int_obj}
%   The |int_obj| procedure returns the PDF object corresponding to 
%   the integer supplied as argument.
%   \begin{tcl}
proc pdf::int_obj {value} {format %d $value}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{real_obj}
% \begin{variable}{precision}
%   The |real_obj| procedure returns the PDF object corresponding to 
%   the real number supplied as argument. The syntax is
%   \begin{quote}
%     |pdf::real_obj| \word{value} \word{precision}\regopt
%   \end{quote}
%   where \word{precision} is the number of decimals that will be 
%   included in the object. If omitted, the value of the |precision| 
%   variable is used, and that defaults to $3$.
%   \begin{tcl}
set pdf::precision 3
proc pdf::real_obj {value {precision -1}} {
   if {$precision&lt;0} then {
      unset precision
      variable precision
   }
   format %.[format %d $precision]f $value
}
%   \end{tcl}
% \end{variable}\end{proc}
% 
% \begin{proc}{string_obj}
%   The |string_obj| procedure returns the PDF string object 
%   corresponding to the argument. Backslashes and parentheses are 
%   escaped. Control characters are converted to escape sequences. 
%   Characters with character code above 255 cause an error to be 
%   thrown (PDF strings correspond more to \Tcllogo\ byte arrays than to 
%   general strings). If the string produced is longer than 100 
%   characters, then backslash--newline sequences are inserted in 
%   suitable places.
%   \begin{tcl}
proc pdf::string_obj {str} {
   if {[regexp "\[^\n\r -\xff\]" $str]} then {
      set estr [string map [list \\ \\\\ ( \\( ) \\) \r \\r \n \\n] $str]
      set str "("
      set len 1
      foreach ch [split $estr {}] {
         scan $ch %c code
         if {$code==92} then {
            append str \\
            incr len
            continue
         } elseif {$code&lt;32} then {
            append str "\\[format %03o $code]"
            incr len 4
         } elseif {$code&lt;256} then {
            append str $ch
            incr len
         } else {
            error "Bad character $ch [format (U+%04x) $code]\
              in PDF string."
         }
         if {$len &gt; 100} then {
            append str \\\n
            set len 0
         }
      }
      append str ")"
   } else {
      set L [list]
      while {[string length $str]&gt;=100} {
         lappend L [string map [list \\ \\\\ ( \\( ) \\) \r \\r \n \\n]\
           [string range $str 0 99]]
         set str [string range $str 100 end]
      }
      if {[string length $str]} then {
         lappend L\
           [string map [list \\ \\\\ ( \\( ) \\) \r \\r \n \\n] $str]
      }
      set str ([join $L \\\n])
   }
   return $str
} 
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{hexstring_obj}
%   The |hexstring_obj| procedure returns the PDF string object, 
%   encoded as hexadecimal digits, that corresponds to the argument. 
%   If the string is longer than 31 characters then it will be broken 
%   on several lines.
%   \begin{tcl}
proc pdf::hexstring_obj {str} {
   set hstr "&lt;"
   set len 1
   foreach ch [split $str {}] {
      scan $ch %c code
      if {$len&gt;=63} then {
         append hstr \n
         set len 0
      }
      if {$code&lt;256} then {
         append hstr [format %02x $code]
         incr len 2
      } else {
         error "Bad character $ch [format (U+%04x) $code]\
           in PDF string."
      }
   }
   append hstr "&gt;"
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{text_obj}
%   The |text_obj| procedure returns the PDF string object, encoded as 
%   hexadecimal digits, that corresponds to the argument string. This is 
%   meant to be used for \emph{text strings} 
%   (see~\cite[Ssec.~4.4.1]{PDFspec}), which are \Tcllogo-style strings 
%   rather than byte arrays. Text strings may contain general Unicode 
%   characters, although they will then be encoded using UTF-16BE.
%   
%   The implementation constructs the 8-bit and 16-bits encodings of the 
%   string in parallel, and only when it is done will it decide which to 
%   return.
%   \begin{tcl}
proc pdf::text_obj {str} {
   set hstr "&lt;"
   set ustr "&lt;FEFF"
   set lenh 1
   set lenu 5
   set eight_ok 1
   foreach {chh chl} [split [encoding convertto unicode $str] {}] {
      scan $chh %c codeh
      scan $chl %c codel
      if {$lenu&gt;=62} then {
         append ustr \n
         set lenu 0
      }
      append ustr [format %02x%02x $codeh $codel]
      incr lenu 4
      if {$codeh&gt;0} then {set eight_ok 0}
      if {!$eight_ok} then {continue}
      if {$lenh&gt;=63} then {
         append hstr \n
         set lenh 0
      }
      append hstr [format %02x $codel]
      incr lenh 2
   }
   append hstr "&gt;"
   append ustr "&gt;"
   if {$eight_ok &amp;&amp; ![string match {&lt;feff*} $hstr]} then {
      return $hstr
   } else {
      return $ustr
   }
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{name_obj}
%   The |name_obj| procedure returns the PDF name object corresponding 
%   to its argument. It is useful mainly for names with strange 
%   characters in them (such as spaces), but most names (e.g.\ dictionary 
%   keys) appearing in PDF files do not require any quoting and can 
%   therefore just as well be written as explicit PDF code.
%   \begin{tcl}
proc pdf::name_obj {str} {
   if {[string length $str]&gt;126} then {
      error "String too long to be a PDF name."
   }
   set res /
   foreach ch [split $str {}] {
      switch -glob -- $ch {
         ( - ) - &lt; - &gt; - \\[ - \\] - \{ - \} - / - % - # {
            scan $ch %c code
            append res [format #%02x $code]
         }
         [!-~] {append res $ch}
         default {
            scan $ch %c code
            append res [format #%02x $code]
         }
      }
   }
   return $res
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{array_obj}
%   The |array_obj| procedure builds an array object of the objects it 
%   is given as arguments. The syntax is
%   \begin{quote}
%     |pdf::array_obj| \word{object}\regstar
%   \end{quote}
%   Newlines are inserted between the objects if it does not appear as 
%   if the object would fit on a single (100 character) line.
%   \begin{tcl}
proc pdf::array_obj {args} {
   set res \[
   set len 1
   foreach item $args {
      if {[string length $item] + $len &gt;= 100} then {
         append res \n
         set len 0
      } elseif {[string length $res]&gt;1} then {
         append res " "
         incr len
      }
      append res $item
      incr len [string length $item]
   }
   if {$len &gt;= 100} then {
      append res \n
   }
   append res \]
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{dict_obj}
%   The |dict_obj| procedure builds a dictionary object from its 
%   arguments. The syntax is
%   \begin{quote}
%     |pdf::dict_obj| 
%     \begin{regexp}[\regstar]\word{key} \word{value}\end{regexp}
%   \end{quote}
%   where each \word{key} must be a name object and each \word{value} 
%   must be an object. It is checked that the number of elements is 
%   correct and that the keys begin with a slash.
%   \begin{tcl}
proc pdf::dict_obj {args} {
   if {[llength $args] % 2 != 0} then {
      error "Not the same number of keys and values."
   }
   set res "&lt;&lt;\n"
   foreach {key value} $args {
      if {![string match {/*} $key]} then {
         error "'$key' isn't a name object."
      }
      if {[string length $key] + [string length $value]&gt;99} then {
         append res $key \n $value \n
      } else {
         append res $key { } $value \n
      }
   }
   append res "&gt;&gt;"
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{null_obj}
%   The |null_obj| procedure returns a null object. It has no arguments.
%   \begin{tcl}
proc pdf::null_obj {} {return null}
%   \end{tcl}
% \end{proc}
% 
% 
% Objects can also be \emph{streams}, but those have a special relation 
% to the file structure and are therefore best treated in conjunction 
% with that. In particular, streams cannot be used as arguments of 
% |array_obj| or |dict_obj|. The arguments of these procedures can 
% however be \emph{indirect references} to objects of any type, but 
% these too are best treated in the context of the basic PDF file 
% structure.
% 
% 
% \subsection{File structure}
% 
% The body of a PDF file consists of a sequence of \emph{indirect 
% objects}, which are mainly a sort of declarations: a pair of integers 
% are associated with an object value. Since any composite object can 
% (and in several cases must) contain a reference to any indirect object, 
% this makes it possible to build up arbitrary data structures. It is 
% however also a complication, since it requires that there is a 
% mechanism for allocating these numbers.
% 
% \begin{arrayvar}{file\meta{fnum}}
%   Every file that \Tcllogo\ opens gets a unique identifier which is 
%   used in calls to |puts| and such. This identifier is also used as 
%   the name of an array in the |pdf| namespace, in which the 
%   procedures below store all auxiliary information they need to create 
%   a proper PDF file.
% \end{arrayvar}
% 
% \begin{arrayentry}{file\meta{fnum}}{!\meta{reference label}}
% \begin{arrayentry}{file\meta{fnum}}{last_object_num}
%   In this API, references to indirect objects can be arbitrary 
%   strings, called \emph{reference labels}. The correspondence to the 
%   object numbers actually found in the file is given by the 
%   \texttt{!}\meta{reference label} entries in the array of the file in 
%   question. The entries in this array are lists with the structure
%   \begin{quote}
%     \word{object number} \word{generation number} \word{file 
%     position}\regopt
%   \end{quote}
%   where the \word{file position} is present only if the indirect 
%   object in question has been written to file already. The 
%   \word{object number} is the number of the object referred to. The 
%   \word{generation number} is currently always zero; it appears that 
%   it can only be nonzero for files that have incrementally updated, 
%   and this API only supports creating a file from scratch. The 
%   \word{file position} is the position in the file of the beginning 
%   of the indirect object begin referred to.
%   
%   The |last_object_num| entry in the array holds the most recently 
%   allocated object number. It is incremented whenever a new reference 
%   label is encountered.
% \end{arrayentry}\end{arrayentry}
% 
% \begin{proc}{obj_ref}
%   The |obj_ref| procedure returns PDF code for an indirect reference 
%   to an object. The syntax is
%   \begin{quote}
%     |pdf::obj_ref| \word{file} \word{reference label}
%   \end{quote}
%   where \word{file} is the indentifier of the PDF file in question. 
%   If the \word{reference label} has not been encountered before for 
%   this particular file, then a new object number is allocated for it.
%   \begin{tcl}
proc pdf::obj_ref {F label} {
   upvar #0 [namespace current]::$F A
   if {![info exists A(!$label)]} then {
      incr A(last_object_num)
      set A(!$label) [list $A(last_object_num) 0]
   }
   format {%d %d R} [lindex $A(!$label) 0] [lindex $A(!$label) 1]
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{begin_stream}
% \begin{proc}{end_stream}
%   The |begin_stream| and |end_stream| procedures delimit the creation 
%   of a \emph{stream object}. Between two such commands, it is possible 
%   to write arbitrary text (usually page descriptors or some sort of 
%   embedded data) to the PDF file and have it inserted correctly into 
%   the file as the data stored in the stream object.
%   
%   The syntax for |begin_stream| is
%   \begin{quote}
%     |pdf::begin_stream| \word{file} \word{reference label}
%     \begin{regexp}[\regstar]\word{key} \word{value}\end{regexp}
%   \end{quote}
%   where \word{file} of course is the file to write to and 
%   \word{reference label} is the string that should be used to 
%   reference this object. Each stream consists of one dictionary part 
%   and one data part, where the primary task of the dictionary part is 
%   to specify how the data part should be interpreted. The most 
%   important element in the dictionary is the \texttt{/Length} key and 
%   its value---these are inserted by the |begin_stream| and 
%   |end_stream| commands, so one needs not worry about those---but if 
%   for example the data part is encoded in some special way (for 
%   example, it might be compressed) then it is necessary to include 
%   additional elements in the dictionary. This is what the \word{key} 
%   and \word{value} arguments are for.
%   
%   \begin{arrayentry}{file\meta{fnum}}{current_stream}
%     The |current_stream| entry in a PDF file array is set if and only 
%     if the current position in that file is inside a stream. It is 
%     not possible to begin a new stream when this entry is set. The 
%     value of this entry is a list with the structure
%     \begin{quote}
%       \word{reference label} \word{start}
%     \end{quote}
%     where \word{reference label} is the reference label of the stream 
%     and \word{start} is the position in the file of the first byte in 
%     the stream data. Both of these are needed at |end_stream| to 
%     record the length of the stream data.
%   \end{arrayentry}
%   
%   \begin{arrayentry}{file\meta{fnum}}{?\meta{reference label}}
%     This kind of entry is used for indirect objects that are lengths 
%     of the stream whose reference label is the \meta{reference label}. 
%     They have the same syntax as their |!| ordinary counterparts.
%   \end{arrayentry}
%   
%   \begin{tcl}
proc pdf::begin_stream {F label args} {
   upvar #0 [namespace current]::$F A
   if {[info exists A(current_stream)]} then {
      error "There is already a stream ([lindex $A(current_stream) 0])\
        being written to in this file."
   }
   if {![info exists A(!$label)]} then {
      incr A(last_object_num)
      set A(!$label) [list $A(last_object_num) 0]
   }
   set A(?$label) [list [incr A(last_object_num)] 0]
   lappend A(!$label) [tell $F]
   puts $F\
     [format {%d %d obj} [lindex $A(!$label) 0] [lindex $A(!$label) 1]]
   puts $F [eval\
     [list dict_obj /Length [format {%d 0 R} $A(last_object_num)]]\
     $args]
   puts $F stream
   set A(current_stream) [list $label [tell $F]]
}
%   \end{tcl}
%   
%   The |end_stream| procedure takes the target file as its only argument. 
%   It finishes off the stream as necessary. It also evaluates 
%   everything that has been placed in the backlog of the file.
%   
%   \begin{arrayentry}{file\meta{fnum}}{backlog}
%     It is not possible to output a new indirect object when a stream 
%     is being written to, but it can still be at such a time that the 
%     need for such an object is discovered. The |backlog| entry 
%     provides a way around that limitation---this entry is a script 
%     that is evaluated (and cleared) at the end of every |end_stream|, 
%     hence commands can be delayed by appending them to this script, 
%     instead of evaluating them immediately.
%     
%     New commands are appended to the |backlog|, and must be preceeded 
%     by a command separator.
%   \end{arrayentry}
%   
%   \begin{tcl}
proc pdf::end_stream {F} {
   upvar #0 [namespace current]::$F A
   if {![info exists A(current_stream)]} then {
      error "There is no stream to end."
   }
   set length [expr {[tell $F] - [lindex $A(current_stream) 1]}]
   set label [lindex $A(current_stream) 0]
   unset A(current_stream)
   puts $F "endstream endobj"
   lappend A(?$label) [tell $F]
   puts $F [format {%d %d obj %d endobj} [lindex $A(?$label) 0]\
     [lindex $A(?$label) 1] $length]
   eval "set A(backlog) {}; $A(backlog)"
}
%   \end{tcl}
% \end{proc}\end{proc}
% 
% \begin{proc}{put_obj}
%   The |put_obj| procedure writes a direct object to a PDF file. The 
%   syntax is
%   \begin{quote}
%     |pdf::put_obj| \word{file} \word{reference label} \word{object}
%   \end{quote}
%   \begin{tcl}
proc pdf::put_obj {F label obj} {
   upvar #0 [namespace current]::$F A
   if {[info exists A(current_stream)]} then {
      append A(backlog) \n [list put_obj $F $label $obj]
      return
   }
   if {![info exists A(!$label)]} then {
      incr A(last_object_num)
      set A(!$label) [list $A(last_object_num) 0]
   }
   lappend A(!$label) [tell $F]
   puts $F\
     [format {%d %d obj} [lindex $A(!$label) 0] [lindex $A(!$label) 1]]
   puts $F $obj
   puts $F endobj
}
%   \end{tcl}
% \end{proc}
% 
% \begin{proc}{rewrite_pdf}
%   The |rewrite_pdf| procedure opens a new PDF file for writing and 
%   initialises the associated data structures. The syntax is
%   \begin{quote}
%     |pdf::rewrite_pdf| \word{file name} \meta{options}
%   \end{quote}
%   and the return value is the identifier of the file opened. The 
%   \word{file name} is of course the name of that file. The 
%   \meta{options} is zero or more of
%   \begin{quote}
%     |-permissions| \word{integer}\\
%     |-header| \word{string}
%   \end{quote}
%   The permissions are the default permissions for the file in question. 
%   If this is not specified, then no such value is specified to |open|, 
%   The header is a string that will be put first in the file (as header). 
%   It defaults to
%   \begin{quote}
%     \texttt{\%PDF-1.3}\\
%     \texttt{\%\r{a}\"a\"o}
%   \end{quote}
%   where the first line is a standard header line, and the second line 
%   is there to help some software understand that the file should be 
%   treated as a binary file. \textbf{Note} that no newline is inserted 
%   after this string; be sure to include it in the string if necessary.
%   \begin{tcl}
proc pdf::rewrite_pdf {name args} {
   set Opt(-header) %PDF-1.3\n%\xe5\xe4\xf6\n
   array set Opt $args
   if {[info exists Opt(-permissions)]} then {
      set F [open $name w $Opt(-permissions)]
   } else {
      set F [open $name w]
   }
   fconfigure $F -translation binary
   puts -nonewline $F $Opt(-header)
   upvar #0 [namespace current]::$F A
   array unset A
   set A(last_object_num) 0
   set A(backlog) ""
   return $F
}
%   \end{tcl}
% \end{proc}
% 
% 
% \begin{proc}{close_pdf}
%   The |close_pdf| procedure performs the non-trivial task of finishing 
%   off the PDF file and closing it. The syntax is
%   \begin{quote}
%     |pdf::close_pdf| \word{file} \word{catalog label}
%     \begin{regexp}[\regstar]\word{key} \word{value}\end{regexp}
%   \end{quote}
%   and the return value is a report detailing any problems 
%   encountered (such as objects that are referred to but never 
%   defined). This is a report rather than an error, because there is 
%   in many cases no sharp distinction. If the return value is 
%   non-empty, then there is probably a bug in your program that needs 
%   to be fixed.
%   
%   The \word{file} is the identifier of the file to write. The 
%   \word{catalog label} is the reference label of the Catalog object 
%   in the document. The remaining arguments can be used to insert 
%   additional information (such as a reference to the Info dictionary 
%   of the document) in the trailer dictionary.
%   
%   \begin{tcl}
proc pdf::close_pdf {F label args} {
   upvar #0 [namespace current]::$F A
   set reportL [list]
%   \end{tcl}
%   The first step is to compile the cross-reference table of the 
%   document. I originally made one subsection for each range of defined 
%   indirect objects, giving the mandatory free entry \#0 a separate 
%   subsection, but for some reason Adobe software didn't like that at 
%   all.\footnote{Whether this means Adobe isn't following their own 
%   standard I leave to others to decide. Neither GhostScript nor 
%   Quartz (the PDF-based graphics system in Mac~OS~X) seemed to have 
%   any problems with this arrangement.} Hence the current 
%   implementation is to make a cross-reference table with only one 
%   subsection, with an explicit free entry for every missing item.
%   
%   \changes{0.1}{2003/02/24}{Changed cross-reference section to avoid 
%      what is probably a bug in Adobe PDF readers. (LH)}
%    
%   The |xrA| array constructed below is a prototype for the 
%   cross-reference section. It is indexed by object number and the 
%   entries have the list structure
%   \begin{quote}
%     \word{file position} \word{generation number} \word{type}
%   \end{quote}
%   Just as in a PDF file, the \word{type} is either \texttt{f} or 
%   \texttt{n} depending on whether the entry is ``free'' or 
%   ``in use''. The \word{file position} and \word{generation number} 
%   are however not padded with zeros, and the \word{file position} is 
%   initially an empty string in the ``free'' entries.
%   
%   This first round simply collects the information and detects 
%   collisions.
%   \begin{tcl}
   set xrA(0) [list "" 65535 f]
   foreach lbl [array names A {[!?]*}] {
      set idx [lindex $A($lbl) 0]
      set ent [list [lindex $A($lbl) 2] [lindex $A($lbl) 1] n]
      if {[llength $A($lbl)]&lt;3} then {
         lappend reportL "There is no indirect object with label:\
           [string range $lbl 1 end]"
         set ent [replace $ent 2 2 f]
      } elseif {[llength $A($lbl)]&gt;3} then {
         lappend reportL "Multiple indirect objects for label\
           [string range $lbl 1 end]; at\
           [join [lrange $A($lbl) 2 end]]."
      }
      if {![info exists xrA($idx)]} then {
         set xrA($idx) $ent
      } elseif {[lindex $xrA($idx) 2]=="f" &amp;&amp; [lindex $ent 2]=="n"}\
      then {
         lappend reportL "This shouldn't happen:\
           There are several reference labels for\
           indirect object $idx. Using that with label:\
           [string range $lbl 1 end]"
         set xrA($idx) $ent
      } else {
         lappend reportL "This shouldn't happen:\
           There are several reference labels for\
           indirect object $idx. Ignoring that with label:\
           [string range $lbl 1 end]"
      }
   }
%   \end{tcl}
%   The second round makes sure that there is a contiguous sequence of 
%   reference numbers and constructs the linked list of free entries.
%   \begin{tcl}
   set last_free 0
   set maxidx [lindex [lsort -integer -decreasing [array names xrA]] 0]
   for {set n $maxidx} {$n&gt;=0} {incr n -1} {
      if {![info exists xrA($n)]} then {
         set xrA($n) [list "" 0 f]
         lappend reportL "This shouldn't happen:\
           Object number $n was allocated, but not\
           assigned a reference label."
      }
      if {[lindex $xrA($n) 2]=="f"} then {
         set xrA($n) [lreplace $xrA($n) 0 0 $last_free]
         set last_free $n
      }
   }
%   \end{tcl}
%   Now the cross-reference section can be written to file.
%   \begin{tcl}
   set startxref [tell $F]
   puts $F xref
   puts $F [format {%d %d} 0 [expr {$maxidx + 1}]]
   for {set n 0} {$n&lt;=$maxidx} {incr n} {
      puts $F [eval [list format {%010d %05d %1s }] $xrA($n)]
   }
%   \end{tcl}
%   Having completed the cross-reference table, the second step is 
%   to write the trailer.
%   \begin{tcl}
   puts $F trailer
   if {[info exists A(!$label)]} then {
      lappend args /Root [format {%d %d R} [lindex $A(!$label) 0]\
        [lindex $A(!$label) 1]]
   } else {
      lappend reportL "ERROR: The document does not have a catalog."\
        "There is no indirect object with label: $label"
   }
   lappend args /Size [array size xrA]
   puts $F [eval [list dict_obj] $args]
   puts $F "startxref\n${startxref}\n%%EOF"
%   \end{tcl}
%   The final step is to close the file and compile the report.
%   \begin{tcl}
   close $F
   join $reportL \n
}
%&lt;/pkg&gt;
%   \end{tcl}
% \end{proc}
% 
% 
% \subsection{Hello World}
% 
% The code below creates a PDF file matching the basic ``Hello World'' 
% example \cite[Sec.~A.2]{PDFspec}.
% 
% \begin{tcl}
%&lt;*example1&gt;
set F [pdf::rewrite_pdf hello.pdf]
pdf::put_obj $F "The catalog" [pdf::dict_obj\
%
  /Type /Catalog\
%
  /Pages [pdf::obj_ref $F "The pages"]\
%
  /Outlines [pdf::obj_ref $F "The outlines"]]
pdf::put_obj $F "The outlines"\
  [pdf::dict_obj /Type /Outlines /Count [pdf::int_obj 0]]
pdf::put_obj $F "The pages" [pdf::dict_obj\
%
  /Type /Pages\
%
  /Count [pdf::int_obj 1]\
%
  /Kids [pdf::array_obj [pdf::obj_ref $F "Page 1"]]]
pdf::put_obj $F "Page 1" [pdf::dict_obj\
%
  /Type /Page\
%
  /Parent [pdf::obj_ref $F "The pages"]\
%
  /Resources [pdf::dict_obj\
%
    /Font [pdf::dict_obj /F1 [pdf::obj_ref $F "Helvetica"]]\
%
    /ProcSet [pdf::obj_ref $F "The procs"]]\
%
  /MediaBox [pdf::array_obj [pdf::int_obj 0] [pdf::int_obj 0]\
    [pdf::int_obj 612] [pdf::int_obj 792]]\
%
  /Contents [pdf::obj_ref $F "Page 1 contents"]]
pdf::begin_stream $F "Page 1 contents"
puts $F {BT}
puts $F {/F1 24 Tf}
puts $F {100 100 Td (Hello World) Tj}
puts $F {ET}
pdf::end_stream $F
pdf::put_obj $F "The procs" [pdf::array_obj /PDF /Text]
pdf::put_obj $F "Helvetica" [pdf::dict_obj\
  /Type /Font /Subtype /Type1\
  /Name /F1 /BaseFont /Helvetica /Encoding /MacRomanEncoding]
pdf::close_pdf $F "The catalog"
%&lt;/example1&gt;
% \end{tcl}
% 
% 
% \begin{thebibliography}{9}
% \bibitem{PDFspec}
%   Adobe Systems Incorporated:
%   \textit{Portable Document Format Reference Manual},
%   version~1.3 (second edition), Addison--Wesley, 1999;
%   ISBN 0-201-61588-6;
%   \textsc{http:}/\slash \texttt{partners.adobe.com}\slash
%   \texttt{asn}\slash \texttt{developer}\slash \texttt{acrosdk}\slash
%   \texttt{docs}\slash \texttt{filefmtspecs}\slash 
%   \texttt{PDFReference13.pdf}.
%   \emph{Note:} There is now a version~1.4 of this specification.
% \end{thebibliography}
% 
% \PrintIndex
% 
% 
\endinput</pre></body></html>