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<a name="String-Input-and-Output"></a>
<div class="header">
<p>
Next: <a href="maxima_377.html#Characters" accesskey="n" rel="next">Characters</a>, Previous: <a href="maxima_375.html#Introduction-to-String-Processing" accesskey="p" rel="previous">Introduction to String Processing</a>, Up: <a href="maxima_374.html#stringproc_002dpkg" accesskey="u" rel="up">stringproc-pkg</a> &nbsp; [<a href="maxima_toc.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="maxima_423.html#Function-and-Variable-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="String-Input-and-Output-1"></a>
<h3 class="section">91.2 String Input and Output</h3>

<p>Example: Formatted printing to a file.
</p>
<div class="example">
<pre class="example">(%i1) s: openw(&quot;file.txt&quot;);
(%o1)                      #&lt;output stream file.txt&gt;
(%i2) control: 
&quot;~2tAn atom: ~20t~a~%~2tand a list: ~20t~{~r ~}~%~2t\
and an integer: ~20t~d~%&quot;$
(%i3) printf( s,control, 'true,[1,2,3],42 )$
(%o3)                                false
(%i4) close(s);
(%o4)                                true
(%i5) s: openr(&quot;file.txt&quot;);
(%o5)                      #&lt;input stream file.txt&gt;
(%i6) while stringp( tmp:readline(s) ) do print(tmp)$
  An atom:          true 
  and a list:       one two three  
  and an integer:   42 
(%i7) close(s)$
</pre></div>

<a name="close"></a><a name="Item_003a-stringproc_002fdeffn_002fclose"></a><dl>
<dt><a name="index-close"></a>Function: <strong>close</strong> <em>(<var>stream</var>) </em></dt>
<dd>
<p>Closes <var>stream</var> and returns <code>true</code> if <var>stream</var> had been open. 
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-input">File input</a>
&middot;<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="flength"></a><a name="Item_003a-stringproc_002fdeffn_002fflength"></a><dl>
<dt><a name="index-flength"></a>Function: <strong>flength</strong> <em>(<var>stream</var>)</em></dt>
<dd>
<p><var>stream</var> has to be an open stream from or to a file. 
<code>flength</code> then returns the number of bytes which are currently present in this file.
</p>
<p>Example: See <a href="#writebyte">writebyte</a> .
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-input">File input</a>
&middot;<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="flush_005foutput"></a><a name="Item_003a-stringproc_002fdeffn_002fflush_005foutput"></a><dl>
<dt><a name="index-flush_005foutput"></a>Function: <strong>flush_output</strong> <em>(<var>stream</var>)</em></dt>
<dd>
<p>Flushes <var>stream</var> where <var>stream</var> has to be an output stream to a file. 
</p>
<p>Example: See <a href="#writebyte">writebyte</a> .
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="fposition"></a><a name="Item_003a-stringproc_002fdeffn_002ffposition"></a><dl>
<dt><a name="index-fposition"></a>Function: <strong>fposition</strong> <em><br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>fposition</tt> (<var>stream</var>) <br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>fposition</tt> (<var>stream</var>, <var>pos</var>)</em></dt>
<dd>
<p>Returns the current position in <var>stream</var>, if <var>pos</var> is not used. 
If <var>pos</var> is used, <code>fposition</code> sets the position in <var>stream</var>.
<var>stream</var> has to be a stream from or to a file and 
<var>pos</var> has to be a positive number.
</p>
<p>Positions in data streams are like in strings or lists 1-indexed, 
i.e. the first element in <var>stream</var> is in position 1.
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-input">File input</a>
&middot;<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="freshline"></a><a name="Item_003a-stringproc_002fdeffn_002ffreshline"></a><dl>
<dt><a name="index-freshline"></a>Function: <strong>freshline</strong> <em><br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>freshline</tt> ()  <br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>freshline</tt> (<var>stream</var>) </em></dt>
<dd>
<p>Writes a new line to the standard output stream 
if the position is not at the beginning of a line and returns <code>true</code>.
Using the optional argument <var>stream</var> the new line is written to that stream. 
There are some cases, where <code>freshline()</code> does not work as expected. 
</p>
<p>See also <a href="#newline">newline</a>.
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="get_005foutput_005fstream_005fstring"></a><a name="Item_003a-stringproc_002fdeffn_002fget_005foutput_005fstream_005fstring"></a><dl>
<dt><a name="index-get_005foutput_005fstream_005fstring"></a>Function: <strong>get_output_stream_string</strong> <em>(<var>stream</var>)</em></dt>
<dd>
<p>Returns a string containing all the characters currently present in 
<var>stream</var> which must be an open string-output stream. 
The returned characters are removed from <var>stream</var>.
</p>
<p>Example: See <a href="#make_005fstring_005foutput_005fstream">make_string_output_stream</a> .
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="make_005fstring_005finput_005fstream"></a><a name="Item_003a-stringproc_002fdeffn_002fmake_005fstring_005finput_005fstream"></a><dl>
<dt><a name="index-make_005fstring_005finput_005fstream"></a>Function: <strong>make_string_input_stream</strong> <em><br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>make_string_input_stream</tt> (<var>string</var>) <br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>make_string_input_stream</tt> (<var>string</var>, <var>start</var>) <br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>make_string_input_stream</tt> (<var>string</var>, <var>start</var>, <var>end</var>)</em></dt>
<dd>
<p>Returns an input stream which contains parts of <var>string</var> and an end of file. 
Without optional arguments the stream contains the entire string 
and is positioned in front of the first character. 
<var>start</var> and <var>end</var> define the substring contained in the stream. 
The first character is available at position 1.
</p> 
<div class="example">
<pre class="example">(%i1) istream : make_string_input_stream(&quot;text&quot;, 1, 4);
(%o1)              #&lt;string-input stream from &quot;text&quot;&gt;
(%i2) (while (c : readchar(istream)) # false do sprint(c), newline())$
t e x 
(%i3) close(istream)$
</pre></div>

<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="make_005fstring_005foutput_005fstream"></a><a name="Item_003a-stringproc_002fdeffn_002fmake_005fstring_005foutput_005fstream"></a><dl>
<dt><a name="index-make_005fstring_005foutput_005fstream"></a>Function: <strong>make_string_output_stream</strong> <em>()</em></dt>
<dd>
<p>Returns an output stream that accepts characters. Characters currently present 
in this stream can be retrieved by <a href="#get_005foutput_005fstream_005fstring">get_output_stream_string</a>.
</p> 
<div class="example">
<pre class="example">(%i1) ostream : make_string_output_stream();
(%o1)               #&lt;string-output stream 09622ea0&gt;
(%i2) printf(ostream, &quot;foo&quot;)$

(%i3) printf(ostream, &quot;bar&quot;)$

(%i4) string : get_output_stream_string(ostream);
(%o4)                            foobar
(%i5) printf(ostream, &quot;baz&quot;)$

(%i6) string : get_output_stream_string(ostream);
(%o6)                              baz
(%i7) close(ostream)$
</pre></div>

<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="newline"></a><a name="Item_003a-stringproc_002fdeffn_002fnewline"></a><dl>
<dt><a name="index-newline"></a>Function: <strong>newline</strong> <em><br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>newline</tt> ()  <br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>newline</tt> (<var>stream</var>) </em></dt>
<dd>
<p>Writes a new line to the standard output stream. 
Using the optional argument <var>stream</var> the new line is written to that stream. 
There are some cases, where <code>newline()</code> does not work as expected. 
</p>
<p>See <a href="#sprint">sprint</a> for an example of using <code>newline()</code>.
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="opena"></a><a name="Item_003a-stringproc_002fdeffn_002fopena"></a><dl>
<dt><a name="index-opena"></a>Function: <strong>opena</strong> <em>(<var>file</var>) </em></dt>
<dd>
<p>Returns a character output stream to <var>file</var>.
If an existing file is opened, <code>opena</code> appends elements at the end of <var>file</var>.
</p>
<p>For binary output see <a href="maxima_324.html#Functions-and-Variables-for-binary-input-and-output">opena_binary</a> .
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="openr"></a><a name="Item_003a-stringproc_002fdeffn_002fopenr"></a><dl>
<dt><a name="index-openr"></a>Function: <strong>openr</strong> <em><br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>openr</tt> (<var>file</var>) <br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>openr</tt> (<var>file</var>, <var>encoding</var>) </em></dt>
<dd>

<p>Returns a character input stream to <var>file</var>.
<code>openr</code> assumes that <var>file</var> already exists.
If reading the file results in a lisp error about its encoding
passing the correct string as the argument <var>encoding</var> might help.
The available encodings and their names depend on the lisp being used.
For sbcl a list of suitable strings can be found at
<a href="http://www.sbcl.org/manual/#External-Formats">http://www.sbcl.org/manual/#External-Formats</a>.
</p>
<p>For binary input see <a href="maxima_324.html#Functions-and-Variables-for-binary-input-and-output">openr_binary</a> .
See also <code><a href="#close">close</a></code> and <code><a href="#openw">openw</a></code>.
</p>
<div class="example">
<pre class="example">(%i1) istream : openr(&quot;data.txt&quot;,&quot;EUC-JP&quot;);
(%o1)     #&lt;FD-STREAM for &quot;file /home/gunter/data.txt&quot; {10099A3AE3}&gt;
(%i2) close(istream);
(%o2)                                true
</pre></div>


<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-input">File input</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="openw"></a><a name="Item_003a-stringproc_002fdeffn_002fopenw"></a><dl>
<dt><a name="index-openw"></a>Function: <strong>openw</strong> <em>(<var>file</var>) </em></dt>
<dd>
<p>Returns a character output stream to <var>file</var>.
If <var>file</var> does not exist, it will be created.
If an existing file is opened, <code>openw</code> destructively modifies <var>file</var>.
</p>
<p>For binary output see <a href="maxima_324.html#Functions-and-Variables-for-binary-input-and-output">openw_binary</a> .
</p>
<p>See also <code><a href="#close">close</a></code> and <code><a href="#openr">openr</a></code>.
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="printf"></a><a name="Item_003a-stringproc_002fdeffn_002fprintf"></a><dl>
<dt><a name="index-printf"></a>Function: <strong>printf</strong> <em><br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>printf</tt> (<var>dest</var>, <var>string</var>) <br>&nbsp;&nbsp;&nbsp;&nbsp;<tt>printf</tt> (<var>dest</var>, <var>string</var>, <var>expr_1</var>, ..., <var>expr_n</var>)</em></dt>
<dd>
<p>Produces formatted output by outputting the characters of control-string 
<var>string</var> and observing that a tilde introduces a directive.
The character after the tilde, possibly preceded by prefix parameters 
and modifiers, specifies what kind of formatting is desired.
Most directives use one or more elements of the arguments 
<var>expr_1</var>, ..., <var>expr_n</var> to create their output.
</p>
<p>If <var>dest</var> is a stream or <code>true</code>, then <code>printf</code> returns <code>false</code>.
Otherwise, <code>printf</code> returns a string containing the output.
By default the streams <var>stdin</var>, <var>stdout</var> and <var>stderr</var> are defined.
If Maxima is running as a network client (which is the normal case if Maxima is communicating
with a graphical user interface, which must be the server) <code>setup-client</code>
will define <var>old_stdout</var> and <var>old_stderr</var>, too.
</p>
<p><code>printf</code> provides the Common Lisp function <code>format</code> in Maxima. 
The following example illustrates the general relation between these two 
functions.
</p>
<div class="example">
<pre class="example">(%i1) printf(true, &quot;R~dD~d~%&quot;, 2, 2);
R2D2
(%o1)                                false
(%i2) :lisp (format t &quot;R~dD~d~%&quot; 2 2)
R2D2
NIL
</pre></div>

<p>The following description is limited to a rough sketch of the possibilities of 
<code>printf</code>.
The Lisp function <code>format</code> is described in detail in many reference books. 
Of good help is e.g. the free available online-manual 
&quot;Common Lisp the Language&quot; by Guy L. Steele. See chapter 22.3.3 there. 
</p>
<p>In addition, <code>printf</code> recognizes two format directives which are not known to Lisp <code>format</code>.
The format directive <code>~m</code> indicates Maxima pretty printer output.
The format directive <code>~h</code> indicates a bigfloat number.
</p>
<div class="example">
<pre class="example">   ~%       new line
   ~&amp;       fresh line
   ~t       tab
   ~$       monetary
   ~d       decimal integer
   ~b       binary integer
   ~o       octal integer
   ~x       hexadecimal integer
   ~br      base-b integer
   ~r       spell an integer
   ~p       plural
   ~f       floating point
   ~e       scientific notation
   ~g       ~f or ~e, depending upon magnitude
   ~h       bigfloat
   ~a       uses Maxima function string
   ~m       Maxima pretty printer output
   ~s       like ~a, but output enclosed in &quot;double quotes&quot;
   ~~       ~
   ~&lt;       justification, ~&gt; terminates
   ~(       case conversion, ~) terminates 
   ~[       selection, ~] terminates 
   ~{       iteration, ~} terminates
</pre></div>

<p>Note that the directive ~* is not supported.
</p>
<p>If <var>dest</var> is a stream or <code>true</code>, then <code>printf</code> returns <code>false</code>.
Otherwise, <code>printf</code> returns a string containing the output.
</p>
<div class="example">
<pre class="example">(%i1) printf( false, &quot;~a ~a ~4f ~a ~@r&quot;, 
              &quot;String&quot;,sym,bound,sqrt(12),144), bound = 1.234;
(%o1)                 String sym 1.23 2*sqrt(3) CXLIV
(%i2) printf( false,&quot;~{~a ~}&quot;,[&quot;one&quot;,2,&quot;THREE&quot;] );
(%o2)                          one 2 THREE 
(%i3) printf(true,&quot;~{~{~9,1f ~}~%~}&quot;,mat ),
          mat = args(matrix([1.1,2,3.33],[4,5,6],[7,8.88,9]))$
      1.1       2.0       3.3 
      4.0       5.0       6.0 
      7.0       8.9       9.0 
(%i4) control: &quot;~:(~r~) bird~p ~[is~;are~] singing.&quot;$
(%i5) printf( false,control, n,n,if n=1 then 1 else 2 ), n=2;
(%o5)                    Two birds are singing.
</pre></div>

<p>The directive ~h has been introduced to handle bigfloats. 
</p>
<div class="example">
<pre class="example">~w,d,e,x,o,p@H
 w : width
 d : decimal digits behind floating point
 e : minimal exponent digits
 x : preferred exponent
 o : overflow character
 p : padding character
 @ : display sign for positive numbers
</pre></div>

<div class="example">
<pre class="example">(%i1) fpprec : 1000$
(%i2) printf(true, &quot;|~h|~%&quot;, 2.b0^-64)$
|0.0000000000000000000542101086242752217003726400434970855712890625|
(%i3) fpprec : 26$
(%i4) printf(true, &quot;|~h|~%&quot;, sqrt(2))$
|1.4142135623730950488016887|
(%i5) fpprec : 24$
(%i6) printf(true, &quot;|~h|~%&quot;, sqrt(2))$
|1.41421356237309504880169|
(%i7) printf(true, &quot;|~28h|~%&quot;, sqrt(2))$
|   1.41421356237309504880169|
(%i8) printf(true, &quot;|~28,,,,,'*h|~%&quot;, sqrt(2))$
|***1.41421356237309504880169|
(%i9) printf(true, &quot;|~,18h|~%&quot;, sqrt(2))$
|1.414213562373095049|
(%i10) printf(true, &quot;|~,,,-3h|~%&quot;, sqrt(2))$
|1414.21356237309504880169b-3|
(%i11) printf(true, &quot;|~,,2,-3h|~%&quot;, sqrt(2))$
|1414.21356237309504880169b-03|
(%i12) printf(true, &quot;|~20h|~%&quot;, sqrt(2))$
|1.41421356237309504880169|
(%i13) printf(true, &quot;|~20,,,,'+h|~%&quot;, sqrt(2))$
|++++++++++++++++++++|
</pre></div>

<p>For conversion of objects to strings also see <code><a href="maxima_16.html#concat">concat</a></code>, <code><a href="maxima_16.html#sconcat">sconcat</a></code>,
<code><a href="maxima_16.html#string">string</a></code> and <code><a href="maxima_378.html#simplode">simplode</a></code>.
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="readbyte"></a><a name="Item_003a-stringproc_002fdeffn_002freadbyte"></a><dl>
<dt><a name="index-readbyte"></a>Function: <strong>readbyte</strong> <em>(<var>stream</var>)</em></dt>
<dd>
<p>Removes and returns the first byte in <var>stream</var> which must be a binary input stream. 
If the end of file is encountered <code>readbyte</code> returns <code>false</code>.
</p>
<p>Example: Read the first 16 bytes from a file encrypted with AES in OpenSSL. 
</p>
<div class="example">
<pre class="example">(%i1) ibase: obase: 16.$

(%i2) in: openr_binary(&quot;msg.bin&quot;);
(%o2)                       #&lt;input stream msg.bin&gt;
(%i3) (L:[],  thru 16. do push(readbyte(in), L),  L:reverse(L));
(%o3) [53, 61, 6C, 74, 65, 64, 5F, 5F, 88, 56, 0DE, 8A, 74, 0FD,
       0AD, 0F0]
(%i4) close(in);
(%o4)                                true
(%i5) map(ascii, rest(L,-8));
(%o5)                      [S, a, l, t, e, d, _, _]
(%i6) salt: octets_to_number(rest(L,8));
(%o6)                          8856de8a74fdadf0
</pre></div>

<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-input">File input</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="readchar"></a><a name="Item_003a-stringproc_002fdeffn_002freadchar"></a><dl>
<dt><a name="index-readchar"></a>Function: <strong>readchar</strong> <em>(<var>stream</var>)</em></dt>
<dd>
<p>Removes and returns the first character in <var>stream</var>. 
If the end of file is encountered <code>readchar</code> returns <code>false</code>.
</p>
<p>Example: See <a href="#make_005fstring_005finput_005fstream">make_string_input_stream</a>.
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-input">File input</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="readline"></a><a name="Item_003a-stringproc_002fdeffn_002freadline"></a><dl>
<dt><a name="index-readline"></a>Function: <strong>readline</strong> <em>(<var>stream</var>) </em></dt>
<dd>
<p>Returns a string containing all characters starting at the current position 
in <var>stream</var> up to the end of the line or <code>false</code> 
if the end of the file is encountered.
</p>
<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-File-input">File input</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="sprint"></a><a name="Item_003a-stringproc_002fdeffn_002fsprint"></a><dl>
<dt><a name="index-sprint"></a>Function: <strong>sprint</strong> <em>(<var>expr_1</var>, &hellip;, <var>expr_n</var>)</em></dt>
<dd>
<p>Evaluates and displays its arguments one after the other &lsquo;on a line&rsquo; starting at
the leftmost position.  The expressions are printed with a space character right next 
to the number, and it disregards line length.  
<code>newline()</code> might be used for line breaking.
</p>
<p>Example: Sequential printing with <code>sprint</code>. 
Creating a new line with <code>newline()</code>.
</p>
<div class="example">
<pre class="example">(%i1) for n:0 thru 19 do sprint(fib(n))$
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181
(%i2) for n:0 thru 22 do ( 
         sprint(fib(n)), 
         if mod(n,10) = 9 then newline() )$
0 1 1 2 3 5 8 13 21 34 
55 89 144 233 377 610 987 1597 2584 4181 
6765 10946 17711 
</pre></div>

<div class=categorybox>
Categories:<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div></dd></dl>

<a name="writebyte"></a><a name="Item_003a-stringproc_002fdeffn_002fwritebyte"></a><dl>
<dt><a name="index-writebyte"></a>Function: <strong>writebyte</strong> <em>(<var>byte</var>, <var>stream</var>)</em></dt>
<dd>
<p>Writes <var>byte</var> to <var>stream</var> which must be a binary output stream. 
<code>writebyte</code> returns <code>byte</code>.
</p>
<p>Example: Write some bytes to a binary file output stream. 
In this example all bytes correspond to printable characters and are printed 
by <code>printfile</code>. 
The bytes remain in the stream until <code>flush_output</code> or <code>close</code> have been called.
</p>
<div class="example">
<pre class="example">(%i1) ibase: obase: 16.$

(%i2) bytes: map(cint, charlist(&quot;GNU/Linux&quot;));
(%o2)                [47, 4E, 55, 2F, 4C, 69, 6E, 75, 78]
(%i3) out: openw_binary(&quot;test.bin&quot;);
(%o3)                      #&lt;output stream test.bin&gt;
(%i4) for i thru 3 do writebyte(bytes[i], out);
(%o4)                                done
(%i5) printfile(&quot;test.bin&quot;)$

(%i6) flength(out);
(%o6)                                  0
(%i7) flush_output(out);
(%o7)                                true
(%i8) flength(out);
(%o8)                                  3
(%i9) printfile(&quot;test.bin&quot;)$
GNU
(%i0A) for b in rest(bytes,3) do writebyte(b, out);
(%o0A)                               done
(%i0B) close(out);
(%o0B)                               true
(%i0C) printfile(&quot;test.bin&quot;)$
GNU/Linux
</pre></div>

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Categories:<a href="maxima_424.html#Category_003a-File-output">File output</a>
&middot;<a href="maxima_424.html#Category_003a-Package-stringproc">Package stringproc</a>
&middot;</div>
</dd></dl>

<a name="Item_003a-stringproc_002fnode_002fCharacters"></a><hr>
<div class="header">
<p>
Next: <a href="maxima_377.html#Characters" accesskey="n" rel="next">Characters</a>, Previous: <a href="maxima_375.html#Introduction-to-String-Processing" accesskey="p" rel="previous">Introduction to String Processing</a>, Up: <a href="maxima_374.html#stringproc_002dpkg" accesskey="u" rel="up">stringproc-pkg</a> &nbsp; [<a href="maxima_toc.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="maxima_423.html#Function-and-Variable-Index" title="Index" rel="index">Index</a>]</p>
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