open_read()

std::ifstream xtd::io::file_info::open_read

(

)

const

Creates a read-only std::ifstream.

Returns

A new read-only std::ifstream.

Exceptions

xtd::unauthorized_access_exception	name is read-only or is a directory.
xtd::io::directory_not_found_exception	The specified path is invalid, such as being on an unmapped drive.
xtd::io::io_exception	The file is already open.

Examples

The following example opens a file as read-only and reads from it.

#include <xtd/io/file_info>
#include <xtd/io/stream_reader>
#include <xtd/io/stream_writer>
#include <xtd/block_scope>
#include <xtd/console>
#include <xtd/startup>
 
using namespace xtd;
using namespace xtd::io;
 
class program {
public:
  static auto main() {
    auto path = "MyTest.txt";
    auto fi = file_info {path};
    
    //Create the file.
    block_scope_(auto fs = fi.create()) {
      auto sw = stream_writer {fs};
      sw.write_line("This is some text in the file.");
    }
    
    //Open the stream and read it back.
    block_scope_(auto fs = fi.open_read()) {
      auto sr = stream_reader {fs};
      while (!sr.end_of_stream())
        console::write_line(sr.read_line());
    }
  }
};
 
startup_(program::main);
 
// This code produces the following output :
// results may vary based on the computer/file structure/etc.:
//
// This is some text in the file.

Remarks

This method returns a read-only std::ifstream object.