# FileHelper

`FileHelper` class provides synchronous and asynchronous methods for the write, read and delete a single file.

## SaveFile()

Synchronously saves a byte array to a file by an absolute path.

```csharp
FileHelper.SaveFile("absolute_file_path", bytes);
```

By default, if the file exists, the `FileHelper` creates a new file with a unique name and returns that name.

```csharp
string existingFilePath = "D:\\readme.txt";
string newFilePath = FileHelper.SaveFile(existingFilePath, bytes); // Returns "D:\\readme_1.txt".
```

All parameters:

| Param name                    | Param type | Description                                                                                                                                                  |
| ----------------------------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| path                          | `string`   | The absolute file path to save to.                                                                                                                           |
| bytes                         | `byte[]`   | The bytes to save to the file.                                                                                                                               |
| createDirIfNotExists          | `bool`     | The flag indicates to create destination directory if not exists. Default value is `true`.                                                                   |
| useSequentialFileNameIfExists | `bool`     | The flag indicates that target file name should be changed by adding sequential postfix if file with specfied name already exists. Default value is `false`. |

## SaveFileAsync()

Asynchronously saves a byte array to a file by an absolute path.

```csharp
await FileHelper.SaveFileAsync("absolute_file_path", bytes);
```

By default, if the file exists, the `FileHelper` creates a new file with a unique name and returns that name.

```csharp
string existingFilePath = "D:\\readme.txt";
string newFilePath = await FileHelper.SaveFileAsync(existingFilePath, bytes); // Returns "D:\\readme_1.txt".
```

All parameters:

| Param name                    | Param type          | Description                                                                                                                                                  |
| ----------------------------- | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| path                          | `string`            | The absolute file path to save to.                                                                                                                           |
| bytes                         | `byte[]`            | The bytes to save to the file.                                                                                                                               |
| createDirIfNotExists          | `bool`              | The flag indicates to create destination directory if not exists. Default value is `true`.                                                                   |
| useSequentialFileNameIfExists | `bool`              | The flag indicates that target file name should be changed by adding sequential postfix if file with specfied name already exists. Default value is `false`. |
| cancellationToken             | `CancellationToken` | The token to monitor for cancellation requests. Default value is `None`.                                                                                     |

## ReadFile()

Synchronously reads a file from an absolute path to a byte array.

```csharp
byte[] bytes = FileHelper.ReadFile(filePath);
```

All parameters:

| Param name       | Param type | Description                                                                        |
| ---------------- | ---------- | ---------------------------------------------------------------------------------- |
| path             | `string`   | The absolute file path to read to.                                                 |
| throwIfNotExists | `bool`     | The flag indicates to throw exception if file not exists. Default value is `true`. |

You can also synchronously reads a file from a stream to a byte array.

```csharp
byte[] bytes = FileHelper.ReadFile(stream);
```

All parameters:

| Param name    | Param type | Description                                           |
| ------------- | ---------- | ----------------------------------------------------- |
| stream        | `Stream`   | The Stream (MemoryStream, FileStream, etc.).          |
| initialLength | `long`     | Length of returning byte array. Default value is `0`. |

## ReadFileAsync()

Asynchronously reads a file from an absolute path to a byte array.

```csharp
byte[] bytes = await FileHelper.ReadFileAsync(filePath);
```

All parameters:

| Param name        | Param type          | Description                                                                        |
| ----------------- | ------------------- | ---------------------------------------------------------------------------------- |
| path              | `string`            | The absolute file path to read to.                                                 |
| throwIfNotExists  | `bool`              | The flag indicates to throw exception if file not exists. Default value is `true`. |
| cancellationToken | `CancellationToken` | The token to monitor for cancellation requests. Default value is `None`.           |

You can also asynchronously reads a file from a stream to a byte array.

```csharp
byte[] bytes = await FileHelper.ReadFileAsync(stream);
```

All parameters:

| Param name        | Param type          | Description                                                              |
| ----------------- | ------------------- | ------------------------------------------------------------------------ |
| stream            | `Stream`            | The Stream (MemoryStream, FileStream, etc.).                             |
| initialLength     | `long`              | Length of returning byte array. Default value is `0`.                    |
| cancellationToken | `CancellationToken` | The token to monitor for cancellation requests. Default value is `None`. |

## DeleteFile()

Deletes a file if it exists.

```csharp
FileHelper.DeleteFile(filePath);
```

All parameters:

| Param name | Param type | Description                          |
| ---------- | ---------- | ------------------------------------ |
| path       | `string`   | The absolute file path to delete to. |

## GetFilePathWithSequentialFileName()

Returns an absolute path with variable destination file name with sequential postfix e.g. ("file\_1.txt", "file\_2.txt").

```csharp
string existingFilePath = "D:\\readme.txt";
string newFilePath = FileHelper.GetFilePathWithSequentialFileName(existingFilePath); // Returns "D:\\readme_1.txt".
```

All parameters:

| Param name | Param type | Description             |
| ---------- | ---------- | ----------------------- |
| path       | `string`   | The absolute file path. |