Class Files

A file may only be opened if permission is granted by an entry in /opt/pigpio/access. This is intended to allow remote access to files in a more or less controlled manner.

Each entry in /opt/pigpio/access takes the form of a file path which may contain wildcards followed by a single letter permission. The permission may be R for read, W for write, U for read/write, and N for no access.

Where more than one entry matches a file the most specific rule applies. If no entry matches a file then access is denied.

Suppose /opt/pigpio/access contains the following entries

Files may be written in directory dir_1 with the exception of file.txt.

Files may be read in directory dir_2.

Files may be read and written in directory dir_3.

If a directory allows read, write, or read/write access then files may be created in that directory.

In an attempt to prevent risky permissions the following paths are ignored in /opt/pigpio/access.

Inheritance

Object

Files

Inherited Members

Object.ToString()

Object.Equals(Object)

Object.Equals(Object, Object)

Object.ReferenceEquals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Namespace: Unosquare.PiGpio.NativeMethods

Syntax

public static class Files

Methods

FileClose(UIntPtr)

This function closes the file associated with handle.

Declaration

public static ResultCode FileClose(UIntPtr handle)

Parameters

Type	Name	Description
UIntPtr	handle	=0, as returned by a call to FileOpen(String, FileModeFlags).

Returns

Type	Description
ResultCode	Returns 0 if OK, otherwise PI_BAD_HANDLE.

Examples

fileClose(h);

FileList(String)

Retrieves a list of files matching the given pattern. See Unosquare.PiGpio.NativeMethods.Files.FileListUnmanaged(System.String,System.Byte[],System.UInt32).

Declaration

public static string[] FileList(string pathPattern)

Parameters

Type	Name	Description
String	pathPattern	The path pattern.

Returns

Type	Description
String[]	A list of matching files.

FileOpen(String, FileModeFlags)

A wrapper function for Unosquare.PiGpio.NativeMethods.Files.FileOpenUnmanaged(System.String,System.UInt32).

Declaration

public static UIntPtr FileOpen(string filePath, FileModeFlags mode)

Parameters

Type	Name	Description
String	filePath	The file path.
FileModeFlags	mode	The mode.

Returns

Type	Description
UIntPtr	A file handle.

Exceptions

Type	Condition
IOException	When the file fails to open.

FileRead(UIntPtr, Byte[], UInt32)

This function reads up to count bytes from the the file associated with handle and writes them to buf.

Declaration

public static int FileRead(UIntPtr handle, byte[] buffer, uint count)

Parameters

Type	Name	Description
UIntPtr	handle	=0, as returned by a call to FileOpen(String, FileModeFlags).
Byte[]	buffer	an array to receive the read data.
UInt32	count	the maximum number of bytes to read.

Returns

Type	Description
Int32	Returns the number of bytes read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, PI_FILE_NOT_ROPEN, or PI_BAD_FILE_WRITE.

Examples

if (fileRead(h, buf, sizeof(buf)) > 0)
{
   // process read data
}

FileRead(UIntPtr, Int32)

Reads from a file handle up to count bytes.

Declaration

public static byte[] FileRead(UIntPtr handle, int count)

Parameters

Type	Name	Description
UIntPtr	handle	The handle.
Int32	count	The count.

Returns

Type	Description
Byte[]	The array of bytes read.

FileSeek(UIntPtr, Int32, SeekMode)

Seeks within a file.

Declaration

public static int FileSeek(UIntPtr handle, int seekOffset, SeekMode seekFrom)

Parameters

Type	Name	Description
UIntPtr	handle	The handle.
Int32	seekOffset	The seek offset.
SeekMode	seekFrom	The seek from.

Returns

Type	Description
Int32	The new byte position within the file.

FileWrite(UIntPtr, Byte[])

Writes the given buffer to a file handle.

Declaration

public static ResultCode FileWrite(UIntPtr handle, byte[] buffer)

Parameters

Type	Name	Description
UIntPtr	handle	The handle.
Byte[]	buffer	The buffer.

Returns

Type	Description
ResultCode	The Result Code.

FileWrite(UIntPtr, Byte[], Int32)

Writes the given buffer to a file handle.

Declaration

public static ResultCode FileWrite(UIntPtr handle, byte[] buffer, int length)

Parameters

Type	Name	Description
UIntPtr	handle	The handle.
Byte[]	buffer	The buffer.
Int32	length	The length.

Returns

Type	Description
ResultCode	The Result Code.

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