diff options
| -rw-r--r-- | io.c | 18 |
1 files changed, 13 insertions, 5 deletions
@@ -1302,13 +1302,21 @@ io_readpartial(argc, argv, io) /* * call-seq: - * ios.read([integer [, buffer]]) => string, buffer, or nil + * ios.read([length [, buffer]]) => string, buffer, or nil * - * Reads at most <i>integer</i> bytes from the I/O stream, or to the - * end of file if <i>integer</i> is omitted or is <code>nil</code>. + * Reads at most <i>length</i> bytes from the I/O stream, or to the + * end of file if <i>length</i> is omitted or is <code>nil</code>. + * <i>length</i> must be a non-negative integer or nil. * If the optional <i>buffer</i> argument is present, it must reference - * a String, which will receive the data. Returns <code>nil</code> - * if called at end of file. + * a String, which will receive the data. + * + * At end of file, it returns <code>nil</code> or <code>""</code> + * depend on <i>length</i>. + * <code><i>ios</i>.read()</code> and + * <code><i>ios</i>.read(nil)</code> returns <code>""</code>. + * <code><i>ios</i>.read(<i>positive-integer</i>)</code> returns nil. + * + * <code><i>ios</i>.read(0)</code> returns <code>""</code>. * * f = File.new("testfile") * f.read(16) #=> "This is line one" |