Windows api read

Printable characters in the character set will always be readable by Notepad, whether you're using binary or text orientation. If you want your strings to be unreadable, you need to encrypt them somehow rather than just write them straight to the file:. However, you can directly write numbers and other non-string data without the encryption, and it will be unrecognizable when opened with Notepad:.

Can you suggest me other, better, way of doing this if this is not OK. I am not sure if writing strigs in binary mode is a good idea. Either you will end up writing the memory locations to the file, which would not be useful in the second time around when you open it or you will end up writng human readable stuff any way. I think what you are looking for is some encrypting mechanism so that you could hide the strings from the others. But as long as the file is consistently read and written as binary, there's no problem.

WriteFile takes a pointer and writes the contents of that pointer, so the only way to get WriteFile to write the addresses is if you had an array of pointers representing the strings and passed it like this:. Thank you all for replies. Usually I do all file manipulation stuff with fopen, fwrite, fread and etc, but I wanted to know how this is done with API. Also I've read somewhere that C function fopen end up on CreateFile under windows os and that "would be wise" to use it directly to gain better performance.

I don't know if this is true, I doubt it. Bottom line: use win32 api directly only if speed is important to your program. Otherwise use either fstream or FILE and associated functions. Personally, I hate fstream because I think its ugly and very clumbsy.

The only advantage is getline used with std::string object. The file extension has nothing to do about file contents. Changing the file extension from. No it doesn't, as the code you posted illustrates. The file extension has nothing to do with whether the file is in binary or text mode. If you are the windows application or driver developer, then might be you need to access the windows registry.

In this article, I will describe the way to how to create and access the key in windows registry. Here, I am assuming you are familiar with windows internals and API. You can find here a complete list of registry functions — MSDN. Before creating the key we need to understand the windows registry hives. The hives are the group of registry keys, subkey, and the registry values.

You can see the registry hives in registry editor left-hand side of the screen. You can open the registry editor to running the command regedit in the search box or Run window. I think now time to see the example code. In this code, you just need to pass the registry hives and key name which you want to create. When opening a new encrypted file, the file inherits the discretionary access control list from its parent directory.

For additional information, see File Encryption. If the function succeeds, the return value is an open handle to the specified file, device, named pipe, or mail slot. To get extended error information, call GetLastError. The text attempts to use the word file only when referring specifically to data stored in an actual file on a file system. This liberal use of the term file is particularly prevalent in constant names and parameter names because of the previously mentioned historical reasons.

When an application is finished using the object handle returned by CreateFile , use the CloseHandle function to close the handle. This not only frees up system resources, but can have wider influence on things like sharing the file or device and committing data to disk. Specifics are noted within this topic as appropriate. To avoid the sharing violation in this scenario, open the remote file or directory with the DELETE access right only, or call DeleteFile without first opening the file or directory for deletion.

Some file systems, such as the NTFS file system, support compression or encryption for individual files and directories. On volumes that have a mounted file system with this support, a new file inherits the compression and encryption attributes of its directory. You cannot use CreateFile to control compression, decompression, or decryption on a file or directory. Windows Server and Windows XP: For backward compatibility purposes, CreateFile does not apply inheritance rules when you specify a security descriptor in lpSecurityAttributes.

To support inheritance, functions that later query the security descriptor of this file may heuristically determine and report that inheritance is in effect. As stated previously, if the lpSecurityAttributes parameter is NULL , the handle returned by CreateFile cannot be inherited by any child processes your application may create. The following information regarding this parameter also applies:.

Note that CreateFile with supersede disposition will fail if performed on a file where there is already an open alternate data stream. Some of these flags should not be combined. Performance gains can be even more noticeable for applications that read large files mostly sequentially, but occasionally skip forward over small ranges of bytes.

If an application moves the file pointer for random access, optimum caching performance most likely will not occur. However, correct operation is still guaranteed. The operating system also requests a write-through of the hard disk's local hardware cache to persistent media. Using these flags together avoids those penalties. For general information about the caching of files and metadata, see File Caching.

Also, the file metadata may still be cached for example, when creating an empty file. To ensure that the metadata is flushed to disk, use the FlushFileBuffers function. In that case, the system can entirely avoid writing the data. If you call CreateFile on a file that is pending deletion as a result of a previous call to DeleteFile , the function fails.

The operating system delays file deletion until all handles to the file are closed. The dwDesiredAccess parameter can be zero, allowing the application to query file attributes without accessing the file if the application is running with adequate security settings.

To avoid the error, specify the same attributes as the existing file. The resulting code is faster, because the redirector can use the cache manager and send fewer SMBs with more data.

For more information, see Creating and Opening Files. Access to the directory is denied if this is done. For more information, see About Directory Management.

Windows Server and Windows XP: Direct access to the disk or to a volume is not restricted in this manner. You can use the CreateFile function to open a physical disk drive or a volume, which returns a direct access storage device DASD handle that can be used with the DeviceIoControl function. This enables you to access the disk or volume directly, for example such disk metadata as the partition table.

However, this type of access also exposes the disk drive or volume to potential data loss, because an incorrect write to a disk using this mechanism could make its contents inaccessible to the operating system. To ensure data integrity, be sure to become familiar with DeviceIoControl and how other APIs behave differently with a direct access handle as opposed to a file system handle. This control code returns the disk number and offset for each of the volume's one or more extents; a volume can span multiple physical disks.

For an example of opening a physical drive, see Calling DeviceIoControl. The following table shows some examples of drive strings. You can also open a volume by referring to its volume name. For more information, see Naming a Volume. A volume contains one or more mounted file systems. Volume handles can be opened as noncached at the discretion of the particular file system, even when the noncached option is not specified in CreateFile.

You should assume that all Microsoft file systems open volume handles as noncached. A file system may or may not require buffer alignment even though the data is noncached.

However, if the noncached option is specified when opening a volume, buffer alignment is enforced regardless of the file system on the volume.

For more information, see Backup. This syntax works for all port numbers and hardware that allows COM port numbers to be specified. For more information about communications, see Communications. To get the standard input handle, use the GetStdHandle function. To get the standard output handle, use GetStdHandle.

For more information, see Mailslots. For more information, see Pipes. Working with a mailslot is shown in Writing to a Mailslot. A tape backup code snippet can found at Creating a Backup Application.

The fileapi.