/*
 *  call-seq:
 *     ios.gets(sep_string=$/)   => string or nil
 *  
 *  Reads the next ``line'' from the I/O stream; lines are separated by
 *  <i>sep_string</i>. A separator of <code>nil</code> reads the entire
 *  contents, and a zero-length separator reads the input a paragraph at
 *  a time (two successive newlines in the input separate paragraphs).
 *  The stream must be opened for reading or an <code>IOError</code>
 *  will be raised. The line read in will be returned and also assigned
 *  to <code>$_</code>. Returns <code>nil</code> if called at end of
 *  file.
 *     
 *     File.new("testfile").gets   #=> "This is line one\n"
 *     $_                          #=> "This is line one\n"
 */

static VALUE
rb_io_gets_m(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE rs, str;

    if (argc == 0) {
        rs = rb_rs;
    }
    else {
        rb_scan_args(argc, argv, "1", &rs);
        if (!NIL_P(rs)) StringValue(rs);
    }
    str = rb_io_getline(rs, io);
    rb_lastline_set(str);

    return str;
}