<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ --> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Paging Screen Output (GNU Octave (version 5.1.0))</title> <meta name="description" content="Paging Screen Output (GNU Octave (version 5.1.0))"> <meta name="keywords" content="Paging Screen Output (GNU Octave (version 5.1.0))"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="makeinfo"> <link href="index.html#Top" rel="start" title="Top"> <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> <link href="Terminal-Output.html#Terminal-Output" rel="up" title="Terminal Output"> <link href="Terminal-Input.html#Terminal-Input" rel="next" title="Terminal Input"> <link href="Terminal-Output.html#Terminal-Output" rel="prev" title="Terminal Output"> <style type="text/css"> <!-- a.summary-letter {text-decoration: none} blockquote.indentedblock {margin-right: 0em} blockquote.smallindentedblock {margin-right: 0em; font-size: smaller} blockquote.smallquotation {font-size: smaller} div.display {margin-left: 3.2em} div.example {margin-left: 3.2em} div.lisp {margin-left: 3.2em} div.smalldisplay {margin-left: 3.2em} div.smallexample {margin-left: 3.2em} div.smalllisp {margin-left: 3.2em} kbd {font-style: oblique} pre.display {font-family: inherit} pre.format {font-family: inherit} pre.menu-comment {font-family: serif} pre.menu-preformatted {font-family: serif} pre.smalldisplay {font-family: inherit; font-size: smaller} pre.smallexample {font-size: smaller} pre.smallformat {font-family: inherit; font-size: smaller} pre.smalllisp {font-size: smaller} span.nolinebreak {white-space: nowrap} span.roman {font-family: initial; font-weight: normal} span.sansserif {font-family: sans-serif; font-weight: normal} ul.no-bullet {list-style: none} --> </style> <link rel="stylesheet" type="text/css" href="octave.css"> </head> <body lang="en"> <a name="Paging-Screen-Output"></a> <div class="header"> <p> Up: <a href="Terminal-Output.html#Terminal-Output" accesskey="u" rel="up">Terminal Output</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> </div> <hr> <a name="Paging-Screen-Output-1"></a> <h4 class="subsubsection">14.1.1.1 Paging Screen Output</h4> <p>When running interactively, Octave normally sends all output directly to the Command Window. However, when using the CLI version of Octave this can create a problem because large volumes of data will stream by before you can read them. In such cases, it is better to use a paging program such as <code>less</code> or <code>more</code> which displays just one screenful at a time. With <code>less</code> (and some versions of <code>more</code>) you can also scan forward and backward, and search for specific items. The pager is enabled by the command <code>more on</code>. </p> <p>Normally, no output is displayed by the pager until just before Octave is ready to print the top level prompt, or read from the standard input (for example, by using the <code>fscanf</code> or <code>scanf</code> functions). This means that there may be some delay before any output appears on your screen if you have asked Octave to perform a significant amount of work with a single command statement. The function <code>fflush</code> may be used to force output to be sent to the pager (or any other stream) immediately. </p> <p>You can select the program to run as the pager with the <code>PAGER</code> function, and configure the pager itself with the <code>PAGER_FLAGS</code> function. </p> <a name="XREFmore"></a><dl> <dt><a name="index-more"></a><em></em> <strong>more</strong></dt> <dt><a name="index-more-1"></a><em></em> <strong>more</strong> <em>on</em></dt> <dt><a name="index-more-2"></a><em></em> <strong>more</strong> <em>off</em></dt> <dd><p>Turn output pagination on or off. </p> <p>Without an argument, <code>more</code> toggles the current state. </p> <p>The current state can be determined via <code>page_screen_output</code>. </p> <p><strong>See also:</strong> <a href="#XREFpage_005fscreen_005foutput">page_screen_output</a>, <a href="#XREFpage_005foutput_005fimmediately">page_output_immediately</a>, <a href="#XREFPAGER">PAGER</a>, <a href="#XREFPAGER_005fFLAGS">PAGER_FLAGS</a>. </p></dd></dl> <a name="XREFPAGER"></a><dl> <dt><a name="index-PAGER"></a><em><var>val</var> =</em> <strong>PAGER</strong> <em>()</em></dt> <dt><a name="index-PAGER-1"></a><em><var>old_val</var> =</em> <strong>PAGER</strong> <em>(<var>new_val</var>)</em></dt> <dt><a name="index-PAGER-2"></a><em></em> <strong>PAGER</strong> <em>(<var>new_val</var>, "local")</em></dt> <dd><p>Query or set the internal variable that specifies the program to use to display terminal output on your system. </p> <p>The default value is normally <code>"less"</code>, <code>"more"</code>, or <code>"pg"</code>, depending on what programs are installed on your system. See <a href="Installation.html#Installation">Installation</a>. </p> <p>When called from inside a function with the <code>"local"</code> option, the variable is changed locally for the function and any subroutines it calls. The original variable value is restored when exiting the function. </p> <p><strong>See also:</strong> <a href="#XREFPAGER_005fFLAGS">PAGER_FLAGS</a>, <a href="#XREFpage_005foutput_005fimmediately">page_output_immediately</a>, <a href="#XREFmore">more</a>, <a href="#XREFpage_005fscreen_005foutput">page_screen_output</a>. </p></dd></dl> <a name="XREFPAGER_005fFLAGS"></a><dl> <dt><a name="index-PAGER_005fFLAGS"></a><em><var>val</var> =</em> <strong>PAGER_FLAGS</strong> <em>()</em></dt> <dt><a name="index-PAGER_005fFLAGS-1"></a><em><var>old_val</var> =</em> <strong>PAGER_FLAGS</strong> <em>(<var>new_val</var>)</em></dt> <dt><a name="index-PAGER_005fFLAGS-2"></a><em></em> <strong>PAGER_FLAGS</strong> <em>(<var>new_val</var>, "local")</em></dt> <dd><p>Query or set the internal variable that specifies the options to pass to the pager. </p> <p>When called from inside a function with the <code>"local"</code> option, the variable is changed locally for the function and any subroutines it calls. The original variable value is restored when exiting the function. </p> <p><strong>See also:</strong> <a href="#XREFPAGER">PAGER</a>, <a href="#XREFmore">more</a>, <a href="#XREFpage_005fscreen_005foutput">page_screen_output</a>, <a href="#XREFpage_005foutput_005fimmediately">page_output_immediately</a>. </p></dd></dl> <a name="XREFpage_005fscreen_005foutput"></a><dl> <dt><a name="index-page_005fscreen_005foutput"></a><em><var>val</var> =</em> <strong>page_screen_output</strong> <em>()</em></dt> <dt><a name="index-page_005fscreen_005foutput-1"></a><em><var>old_val</var> =</em> <strong>page_screen_output</strong> <em>(<var>new_val</var>)</em></dt> <dt><a name="index-page_005fscreen_005foutput-2"></a><em></em> <strong>page_screen_output</strong> <em>(<var>new_val</var>, "local")</em></dt> <dd><p>Query or set the internal variable that controls whether output intended for the terminal window that is longer than one page is sent through a pager. </p> <p>This allows you to view one screenful at a time. Some pagers (such as <code>less</code>—see <a href="Installation.html#Installation">Installation</a>) are also capable of moving backward on the output. </p> <p>When called from inside a function with the <code>"local"</code> option, the variable is changed locally for the function and any subroutines it calls. The original variable value is restored when exiting the function. </p> <p><strong>See also:</strong> <a href="#XREFmore">more</a>, <a href="#XREFpage_005foutput_005fimmediately">page_output_immediately</a>, <a href="#XREFPAGER">PAGER</a>, <a href="#XREFPAGER_005fFLAGS">PAGER_FLAGS</a>. </p></dd></dl> <a name="XREFpage_005foutput_005fimmediately"></a><dl> <dt><a name="index-page_005foutput_005fimmediately"></a><em><var>val</var> =</em> <strong>page_output_immediately</strong> <em>()</em></dt> <dt><a name="index-page_005foutput_005fimmediately-1"></a><em><var>old_val</var> =</em> <strong>page_output_immediately</strong> <em>(<var>new_val</var>)</em></dt> <dt><a name="index-page_005foutput_005fimmediately-2"></a><em></em> <strong>page_output_immediately</strong> <em>(<var>new_val</var>, "local")</em></dt> <dd><p>Query or set the internal variable that controls whether Octave sends output to the pager as soon as it is available. </p> <p>Otherwise, Octave buffers its output and waits until just before the prompt is printed to flush it to the pager. </p> <p>When called from inside a function with the <code>"local"</code> option, the variable is changed locally for the function and any subroutines it calls. The original variable value is restored when exiting the function. </p> <p><strong>See also:</strong> <a href="#XREFpage_005fscreen_005foutput">page_screen_output</a>, <a href="#XREFmore">more</a>, <a href="#XREFPAGER">PAGER</a>, <a href="#XREFPAGER_005fFLAGS">PAGER_FLAGS</a>. </p></dd></dl> <a name="XREFfflush"></a><dl> <dt><a name="index-fflush"></a><em></em> <strong>fflush</strong> <em>(<var>fid</var>)</em></dt> <dd><p>Flush output to file descriptor <var>fid</var>. </p> <p><code>fflush</code> returns 0 on success and an OS dependent error value (-1 on Unix) on error. </p> <p>Programming Note: Flushing is useful for ensuring that all pending output makes it to the screen before some other event occurs. For example, it is always a good idea to flush the standard output stream before calling <code>input</code>. </p> <p><strong>See also:</strong> <a href="Opening-and-Closing-Files.html#XREFfopen">fopen</a>, <a href="Opening-and-Closing-Files.html#XREFfclose">fclose</a>. </p></dd></dl> <hr> <div class="header"> <p> Up: <a href="Terminal-Output.html#Terminal-Output" accesskey="u" rel="up">Terminal Output</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> </div> </body> </html>