read()

static int32 xtd::console::read ( )

static

Reads the next character from the standard input stream.

Returns

int32 The next character from the input stream, or negative one (-1) if there are currently no more characters to be read

Remarks

The Read method blocks its return while you type input characters; it terminates when you press the Enter key.

Pressing Enter appends a platform-dependent line termination sequence to your input (for example, Windows appends a carriage return-linefeed sequence).

Subsequent calls to the Read method retrieve your input one character at a time. After the final character is retrieved, Read blocks its return again and the cycle repeats.

Note that you will not get a property value of -1 unless you perform one of the following actions: simultaneously press the Control modifier key and Z console key (CTRL+Z),

which signals the end-of-file condition; press an equivalent key that signals the end-of-file condition, such as the F6 function key in Windows; or redirect the input stream to a source,

such as a text file, that has an actual end-of-file character.

Example

The following example demonstrates the Read method.

#include <xtd/char_object>
#include <xtd/console>
#include <xtd/convert>
 
using namespace xtd;
 
auto main() -> int {
  auto m1 = "\nType a string of text then press Enter. "
  "Type '+' anywhere in the text to quit:\n";
  auto m2 = "Character '{0}' is hexadecimal 0x{1:x4}.";
  auto m3 = "Character     is hexadecimal 0x{0:x4}.";
  auto ch = U'0';
  //
  console::write_line(m1);
  do {
    auto x = console::read();
    try {
      ch = convert::to_char32(x);
      if (char_object::is_white_space(ch)) {
        console::write_line(m3, x);
        if (ch == 0x0a)
          console::write_line(m1);
      } else
        console::write_line(m2, ch, x);
    } catch (const overflow_exception& e) {
      console::write_line("{0} Value read = {1}.", e.message(), x);
      ch = char_object::min_value;
      console::write_line(m1);
    }
  } while (ch != '+');
}
 
// This code produces the following output :
//
// Type a string of text then press Enter. Type '+' anywhere in the text to quit:
//
// The quick brown fox.
// Character 'T' is hexadecimal 0x0054.
// Character 'h' is hexadecimal 0x0068.
// Character 'e' is hexadecimal 0x0065.
// Character     is hexadecimal 0x0020.
// Character 'q' is hexadecimal 0x0071.
// Character 'u' is hexadecimal 0x0075.
// Character 'i' is hexadecimal 0x0069.
// Character 'c' is hexadecimal 0x0063.
// Character 'k' is hexadecimal 0x006b.
// Character     is hexadecimal 0x0020.
// Character 'b' is hexadecimal 0x0062.
// Character 'r' is hexadecimal 0x0072.
// Character 'o' is hexadecimal 0x006f.
// Character 'w' is hexadecimal 0x0077.
// Character 'n' is hexadecimal 0x006e.
// Character     is hexadecimal 0x0020.
// Character 'f' is hexadecimal 0x0066.
// Character 'o' is hexadecimal 0x006f.
// Character 'x' is hexadecimal 0x0078.
// Character '.' is hexadecimal 0x002e.
// Character     is hexadecimal 0x000d.
// Character     is hexadecimal 0x000a.
//
// Type a string of text then press Enter. Type '+' anywhere in the text to quit:
//
// ^Z
// Value was either too large or too small for a character. Value read = -1.
//
// Type a string of text then press Enter. Type '+' anywhere in the text to quit:
//
// +
// Character '+' is hexadecimal 0x002b.