diff options
Diffstat (limited to 'docsrc/xlisp/xlisp-doc/reference/read-byte.htm')
| -rw-r--r-- | docsrc/xlisp/xlisp-doc/reference/read-byte.htm | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/docsrc/xlisp/xlisp-doc/reference/read-byte.htm b/docsrc/xlisp/xlisp-doc/reference/read-byte.htm new file mode 100644 index 0000000..4047ae6 --- /dev/null +++ b/docsrc/xlisp/xlisp-doc/reference/read-byte.htm @@ -0,0 +1,100 @@ +<html><head><title>XLISP read-byte</title>
+
+<link rel="stylesheet" type="text/css" href="reference.css">
+
+</head>
+
+<body>
+
+<a href="../start.htm">Nyquist / XLISP 2.0</a> -
+<a href="../manual/contents.htm">Contents</a> |
+<a href="../tutorials/tutorials.htm">Tutorials</a> |
+<a href="../examples/examples.htm">Examples</a> |
+<a href="reference-index.htm">Reference</a>
+
+<hr>
+
+<h1>read-byte</h1>
+
+<hr>
+
+<p><table cellpadding="0" cellspacing="0" style="margin-left:10px"><tbody>
+<tr valign="top">
+ <td><nobr>Type:</nobr></td>
+ <td><nobr> - </nobr></td>
+ <td width="100%"><nobr>function (subr)</nobr></td>
+</tr>
+<tr valign="top">
+ <td><nobr>Source:</nobr></td>
+ <td><nobr> - </nobr></td>
+ <td width="100%"><nobr>xlfio.c</nobr></td>
+</tr>
+</tbody></table></p>
+
+<h2>Syntax</h2>
+
+<dl>
+<dt>(read-byte [<i>source</i>])</dt>
+<dd><i>source</i> - an optional source, must be a file pointer or stream,
+default is <a href="global-standard-input.htm">*standard-input*</a><br>
+returns - the byte as an integer</dd>
+</dl>
+
+<h2>Description</h2>
+
+<p>The 'read-byte' function reads a single character from the specified
+'source'. The character read is returned as an integer value for the result.
+The 'source' may be a file pointer or a stream. If there is no 'source',
+<a href="global-standard-input.htm">*standard-input*</a> is the default. If an
+end-of-file is encountered in the 'source', then
+<a href="nil.htm">NIL</a> will be returned as the result.</p>
+
+<h2>Examples</h2>
+
+<pre class="example">
+(setq fp (open "f" :direction :output)) <font color="#008844">; set up file</font>
+(print 12.34 fp)
+(close fp)
+
+(setq fp (open "f" :direction :input)) <font color="#008844">; now read the file</font>
+(read-byte fp) <font color="#008844">; returns 49 - equals "1"</font>
+(read-byte fp) <font color="#008844">; returns 50 - equals "2"</font>
+(read-byte fp) <font color="#008844">; returns 46 - equals "."</font>
+(read-byte fp) <font color="#008844">; returns 51 - equals "3"</font>
+(read-byte fp) <font color="#008844">; returns 52 - equals "4"</font>
+(read-byte fp) <font color="#008844">; returns 10 - equals "\n"</font>
+(read-byte fp) <font color="#008844">; returns NIL - empty</font>
+(close fp)
+</pre>
+
+<p><b>Common Lisp:</b> The XLISP and Common Lisp 'read-byte' functions are
+compatible for simple cases. They both allow for the optional 'source'.
+However, in Common Lisp, there are additional parameters which occur right
+after 'source'. So, when porting from Common Lisp to XLISP, remember there
+are additional arguments in Common Lisp's 'read-byte' function.</p>
+
+<p><b>Common Lisp:</b> Common Lisp specifies that 'read' operations with a
+'source' of <a href="nil.htm">NIL</a> will come from
+<a href="global-standard-input.htm">*standard-input*</a>. XLISP does not read the
+input from <a href="global-standard-input.htm">*standard-input*</a> with a
+'source' of <a href="nil.htm">NIL</a>. Common Lisp also
+specifies that a 'source' of <a href="t.htm"> T </a>
+will read from *terminal-io* which is not defined in XLISP by default. XLISP
+does not allow <a href="t.htm"> T </a> as a valid
+argument for 'source'.</p>
+
+<p>See the
+<a href="../manual/xlisp-man-029.htm#read-byte">read-byte</a>
+function in the <nobr>XLISP 2.0</nobr> manual.</p>
+
+<p><nobr> <a href="#top">Back to Top</nobr></a></p>
+
+<hr>
+
+<a href="../start.htm">Nyquist / XLISP 2.0</a> -
+<a href="../manual/contents.htm">Contents</a> |
+<a href="../tutorials/tutorials.htm">Tutorials</a> |
+<a href="../examples/examples.htm">Examples</a> |
+<a href="reference-index.htm">Reference</a>
+
+</body></html>
\ No newline at end of file |