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<a name="Paging-Screen-Output"></a>
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Up: <a rel="up" accesskey="u" href="Terminal-Output.html#Terminal-Output">Terminal Output</a>
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<h5 class="subsubsection">14.1.1.1 Paging Screen Output</h5>
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<p>When running interactively, Octave normally sends any output intended
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for your terminal that is more than one screen long to a paging program,
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such as <code>less</code> or <code>more</code>. This avoids the problem of having a
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large volume of output stream by before you can read it. With
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<code>less</code> (and some versions of <code>more</code>) you can also scan forward
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and backward, and search for specific items.
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<p>Normally, no output is displayed by the pager until just before Octave
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is ready to print the top level prompt, or read from the standard input
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(for example, by using the <code>fscanf</code> or <code>scanf</code> functions).
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This means that there may be some delay before any output appears on
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your screen if you have asked Octave to perform a significant amount of
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work with a single command statement. The function <code>fflush</code> may be
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used to force output to be sent to the pager (or any other stream)
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<p>You can select the program to run as the pager using the <code>PAGER</code>
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function, and you can turn paging off by using the function
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<p><a name="doc_002dmore"></a>
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— Command: <b>more</b><var><a name="index-more-663"></a></var><br>
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— Command: <b>more</b><var> on<a name="index-more-664"></a></var><br>
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— Command: <b>more</b><var> off<a name="index-more-665"></a></var><br>
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<blockquote><p>Turn output pagination on or off. Without an argument, <code>more</code>
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toggles the current state.
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</p></blockquote></div>
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<p><a name="doc_002dPAGER"></a>
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— Built-in Function: <var>val</var> = <b>PAGER</b> ()<var><a name="index-PAGER-666"></a></var><br>
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— Built-in Function: <var>old_val</var> = <b>PAGER</b> (<var>new_val</var>)<var><a name="index-PAGER-667"></a></var><br>
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<blockquote><p>Query or set the internal variable that specifies the program to use
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to display terminal output on your system. The default value is
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normally <code>"less"</code>, <code>"more"</code>, or
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<code>"pg"</code>, depending on what programs are installed on your system.
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See <a href="Installation.html#Installation">Installation</a>.
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<strong>See also:</strong> more, page_screen_output, page_output_immediately, PAGER_FLAGS.
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</p></blockquote></div>
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<p><a name="doc_002dPAGER_005fFLAGS"></a>
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— Built-in Function: <var>val</var> = <b>PAGER_FLAGS</b> ()<var><a name="index-PAGER_005fFLAGS-668"></a></var><br>
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— Built-in Function: <var>old_val</var> = <b>PAGER_FLAGS</b> (<var>new_val</var>)<var><a name="index-PAGER_005fFLAGS-669"></a></var><br>
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<blockquote><p>Query or set the internal variable that specifies the options to pass
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<strong>See also:</strong> PAGER.
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</p></blockquote></div>
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<p><a name="doc_002dpage_005fscreen_005foutput"></a>
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— Built-in Function: <var>val</var> = <b>page_screen_output</b> ()<var><a name="index-page_005fscreen_005foutput-670"></a></var><br>
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— Built-in Function: <var>old_val</var> = <b>page_screen_output</b> (<var>new_val</var>)<var><a name="index-page_005fscreen_005foutput-671"></a></var><br>
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<blockquote><p>Query or set the internal variable that controls whether output intended
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for the terminal window that is longer than one page is sent through a
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pager. This allows you to view one screenful at a time. Some pagers
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(such as <code>less</code>—see <a href="Installation.html#Installation">Installation</a>) are also capable of moving
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backward on the output.
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</p></blockquote></div>
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<p><a name="doc_002dpage_005foutput_005fimmediately"></a>
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— Built-in Function: <var>val</var> = <b>page_output_immediately</b> ()<var><a name="index-page_005foutput_005fimmediately-672"></a></var><br>
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— Built-in Function: <var>val</var> = <b>page_output_immediately</b> (<var>new_val</var>)<var><a name="index-page_005foutput_005fimmediately-673"></a></var><br>
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<blockquote><p>Query or set the internal variable that controls whether Octave sends
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output to the pager as soon as it is available. Otherwise, Octave
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buffers its output and waits until just before the prompt is printed to
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flush it to the pager.
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</p></blockquote></div>
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<p><a name="doc_002dfflush"></a>
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— Built-in Function: <b>fflush</b> (<var>fid</var>)<var><a name="index-fflush-674"></a></var><br>
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<blockquote><p>Flush output to <var>fid</var>. This is useful for ensuring that all
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pending output makes it to the screen before some other event occurs.
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For example, it is always a good idea to flush the standard output
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stream before calling <code>input</code>.
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<p><code>fflush</code> returns 0 on success and an OS dependent error value
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(−1 on unix) on error.
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<strong>See also:</strong> fopen, fclose.
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</p></blockquote></div>
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