FFileHelper Struct Reference

#include <FileHelper.h>

Public Types
enum class	EHashOptions { None =0 , EnableVerify =1<<0 , ErrorMissingHash =1<<1 }
enum class	EEncodingOptions {   AutoDetect , ForceAnsi , ForceUnicode , ForceUTF8 ,   ForceUTF8WithoutBOM }
enum class	EColorChannel {   R , G , B , A ,   All }

Public Member Functions
enum	UE_DEPRECATED (5.0, "EChannelMask has been deprecated in favor of EColorChannel") EChannelMask

Static Public Member Functions
static CORE_API void	BufferToString (FString &Result, const uint8 *Buffer, int32 Size)
static CORE_API bool	LoadFileToArray (TArray< uint8 > &Result, const TCHAR *Filename, uint32 Flags=0)
static CORE_API bool	LoadFileToArray (TArray64< uint8 > &Result, const TCHAR *Filename, uint32 Flags=0)
static CORE_API bool	LoadFileInBlocks (FStringView Filename, TFunctionRef< void(FMemoryView)> BlockVisitor, int64 Offset=0, int64 Size=-1, uint32 Flags=0, int64 BlockSize=0)
static CORE_API bool	LoadFileToString (FString &Result, FArchive &Reader, EHashOptions VerifyFlags=EHashOptions::None)
static CORE_API bool	LoadFileToString (FString &Result, const TCHAR *Filename, EHashOptions VerifyFlags=EHashOptions::None, uint32 ReadFlags=0)
static CORE_API bool	LoadFileToString (FString &Result, IPlatformFile *PlatformFile, const TCHAR *Filename, EHashOptions VerifyFlags=EHashOptions::None, uint32 ReadFlags=0)
static CORE_API bool	LoadFileToStringArray (TArray< FString > &Result, const TCHAR *Filename)
static CORE_API bool	LoadFileToStringArray (TArray< FString > &Result, const TCHAR *Filename, EHashOptions VerifyFlags)
static CORE_API bool	LoadFileToStringArrayWithPredicate (TArray< FString > &Result, const TCHAR *Filename, TFunctionRef< bool(const FString &)> Predicate)
static CORE_API bool	LoadFileToStringArrayWithPredicate (TArray< FString > &Result, const TCHAR *Filename, TFunctionRef< bool(const FString &)> Predicate, EHashOptions VerifyFlags)
static CORE_API bool	LoadFileToStringWithLineVisitor (const TCHAR *Filename, TFunctionRef< void(FStringView Line)> Visitor)
static CORE_API bool	SaveArrayToFile (TArrayView64< const uint8 > Array, const TCHAR *Filename, IFileManager *FileManager=&IFileManager::Get(), uint32 WriteFlags=0)
static CORE_API bool	SaveArrayToFile (const TArray64< uint8 > &Array, const TCHAR *Filename, IFileManager *FileManager=&IFileManager::Get(), uint32 WriteFlags=0)
static CORE_API bool	SaveStringToFile (FStringView String, const TCHAR *Filename, EEncodingOptions EncodingOptions=EEncodingOptions::AutoDetect, IFileManager *FileManager=&IFileManager::Get(), uint32 WriteFlags=0)
static CORE_API bool	SaveStringArrayToFile (const TArray< FString > &Lines, const TCHAR *Filename, EEncodingOptions EncodingOptions=EEncodingOptions::AutoDetect, IFileManager *FileManager=&IFileManager::Get(), uint32 WriteFlags=0)
static CORE_API bool	CreateBitmap (const TCHAR *Pattern, int32 DataWidth, int32 DataHeight, const struct FColor *Data, FIntRect *SubRectangle=NULL, IFileManager *FileManager=&IFileManager::Get(), FString *OutFilename=NULL, bool bInWriteAlpha=false, EColorChannel ColorChannel=EColorChannel::All)
static CORE_API bool	GenerateNextBitmapFilename (const FString &Pattern, const FString &Extension, FString &OutFilename, IFileManager *FileManager=&IFileManager::Get())
static CORE_API void	GenerateDateTimeBasedBitmapFilename (const FString &Pattern, const FString &Extension, FString &OutFilename)
static CORE_API bool	LoadANSITextFileToStrings (const TCHAR *InFilename, IFileManager *InFileManager, TArray< FString > &OutStrings)
static CORE_API bool	IsFilenameValidForSaving (const FString &Filename, FText &OutError)
static PRAGMA_DISABLE_DEPRECATION_WARNINGS CORE_API bool	CreateBitmap (const TCHAR *Pattern, int32 DataWidth, int32 DataHeight, const struct FColor *Data, FIntRect *SubRectangle, IFileManager *FileManager, FString *OutFilename, bool bInWriteAlpha, EChannelMask ChannelMask)

Member Enumeration Documentation

EColorChannel

enum class FFileHelper::EColorChannel

strong

Enumerator
R
G
B
A
All

EEncodingOptions

enum class FFileHelper::EEncodingOptions

strong

Enumerator
AutoDetect
ForceAnsi
ForceUnicode
ForceUTF8
ForceUTF8WithoutBOM

EHashOptions

enum class FFileHelper::EHashOptions

strong

Enumerator
None
EnableVerify	Enable the async task for verifying the hash for the file being loaded
ErrorMissingHash	A missing hash entry should trigger an error

Member Function Documentation

BufferToString()

void FFileHelper::BufferToString ( FString &  Result, const uint8 *  Buffer, int32  Size  )

static

Load a text file to an FString. Supports all combination of ANSI/Unicode files and platforms.

Converts an arbitrary text buffer to an FString. Supports all combination of ANSI/Unicode files and platforms.

CreateBitmap() [1/2]

static PRAGMA_DISABLE_DEPRECATION_WARNINGS CORE_API bool FFileHelper::CreateBitmap ( const TCHAR *  Pattern, int32  DataWidth, int32  DataHeight, const struct FColor *  Data, FIntRect *  SubRectangle, IFileManager *  FileManager, FString *  OutFilename, bool  bInWriteAlpha, EChannelMask  ChannelMask  )

static

CreateBitmap() [2/2]

static CORE_API bool FFileHelper::CreateBitmap ( const TCHAR *  Pattern, int32  DataWidth, int32  DataHeight, const struct FColor *  Data, FIntRect *  SubRectangle = NULL, IFileManager *  FileManager = &IFileManager::Get(), FString *  OutFilename = NULL, bool  bInWriteAlpha = false, EColorChannel  ColorChannel = EColorChannel::All  )

static

Saves a 24/32Bit BMP file to disk for debug image dump purposes

for general image saving (to BMP or any other format); use FImageUtils::SaveImage instead CreateBitmap is mainly for debug dump images

note this also calls SendDataToPCViaUnrealConsole and uses GenerateNextBitmapFilename if Pattern does not have ".bmp" on it

Parameters

Pattern	filename with path, must not be 0, if with "bmp" extension (e.g. "out.bmp") the filename stays like this, if without (e.g. "out") automatic index numbers are addended (e.g. "out00002.bmp")
DataWidth	- Width of the bitmap supplied in Data >0
DataHeight	- Height of the bitmap supplied in Data >0
Data	must not be 0
SubRectangle	optional, specifies a sub-rectangle of the source image to save out. If NULL, the whole bitmap is saved
FileManager	must not be 0
OutFilename	optional, if specified filename will be output
bInWriteAlpha	optional, specifies whether to write out the alpha channel. Will force BMP V4 format.
ColorChannel	optional, specifies a specific channel to write out (will be written out to all channels gray scale).

Returns

true if success

GenerateDateTimeBasedBitmapFilename()

void FFileHelper::GenerateDateTimeBasedBitmapFilename ( const FString &  Pattern, const FString &  Extension, FString &  OutFilename  )

static

Generates the next unique bitmap filename with a specified extension

Parameters

Pattern	Filename with path, but without extension.
Extension	File extension to be appended
OutFilename	Reference to an FString where the newly generated filename will be placed

Returns

true if success

Generates the next unique bitmap filename with a specified extension

Parameters

Pattern	Filename with path, but without extension. @oaran Extension File extension to be appended
OutFilename	Reference to an FString where the newly generated filename will be placed

Returns

true if success

GenerateNextBitmapFilename()

bool FFileHelper::GenerateNextBitmapFilename ( const FString &  Pattern, const FString &  Extension, FString &  OutFilename, IFileManager *  FileManager = &IFileManager::Get()  )

static

Generates the next unique bitmap filename with a specified extension

Parameters

Pattern	Filename with path, but without extension.
Extension	File extension to be appended
OutFilename	Reference to an FString where the newly generated filename will be placed
FileManager	Reference to a IFileManager (or the global instance by default)

Returns

true if success

Generates the next unique bitmap filename with a specified extension

Parameters

Pattern	Filename with path, but without extension. @oaran Extension File extension to be appended
OutFilename	Reference to an FString where the newly generated filename will be placed
FileManager	Reference to a IFileManager (or the global instance by default)

Returns

true if success

IsFilenameValidForSaving()

bool FFileHelper::IsFilenameValidForSaving ( const FString &  Filename, FText &  OutError  )

static

Checks to see if a filename is valid for saving. A filename must be under FPlatformMisc::GetMaxPathLength() to be saved

Parameters

Filename	Filename, with or without path information, to check.
OutError	If an error occurs, this is the reason why

LoadANSITextFileToStrings()

bool FFileHelper::LoadANSITextFileToStrings ( const TCHAR *  InFilename, IFileManager *  InFileManager, TArray< FString > &  OutStrings  )

static

Load the given ANSI text file to an array of strings - one FString per line of the file. Intended for use in simple text parsing actions

Parameters

InFilename	The text file to read, full path
InFileManager	The filemanager to use - NULL will use &IFileManager::Get()
OutStrings	The array of FStrings to fill in

Returns

bool true if successful, false if not

LoadFileInBlocks()

bool FFileHelper::LoadFileInBlocks ( FStringView  Filename, TFunctionRef< void(FMemoryView)>  BlockVisitor, int64  Offset = 0, int64  Size = -1, uint32  Flags = 0, int64  BlockSize = 0  )

static

Load a binary file a block at a time into a buffer and call the visitor each time the buffer is populated with a new block. This uses less memory and has higher cache coherency than loading the entire file into a block of bytes, and is more performant than reading the file a byte at a time. Useful for e.g. hashing or parsing.

Parameters

Filename	The file to read
BlockVisitor	Function called repeatedly with each sequential block. Size of the input might change for performance and should not be assumed. Possibly the entire file will be passed in a single block. If LoadFileInBlocks returns true, the sum of sizes in each call to BlockVisitor equals the size of the requested range of the the file on disk. If the requested range has size 0, LoadFileInBlocks will return true and the BlockVisitor will not be called.
Offset	Start of the range of bytes to read from the file. If less than zero or larger than filesize, it will be silently clamped to the [0,FileSize] range. This may result in LoadFileInBlocks returning true but using an empty range and not calling BlockVisitor.
Length	of the range of bytes to read from the file. If less than zero, all bytes between Offset and end of file are read. If larger than the size of the range between Offset and end of file, it will be silently shortened to the size of the range.
Flags	Flags to pass to IFileManager::CreateFileReader
BlockSize	Size of the internally-allocated buffer to read bytes into and pass to each call to BlockVisitor. Sizes <= 0 use the default-selected block size for the current platform.

LoadFileToArray() [1/2]

bool FFileHelper::LoadFileToArray ( TArray64< uint8 > &  Result, const TCHAR *  Filename, uint32  Flags = 0  )

static

Load a binary file to a dynamic array with two uninitialized bytes at end as padding.

Parameters

Result	Receives the contents of the file
Filename	The file to read
Flags	Flags to pass to IFileManager::CreateFileReader

Load a binary file to a dynamic array with two uninitialized bytes at end as padding. TArray64 version.

LoadFileToArray() [2/2]

bool FFileHelper::LoadFileToArray ( TArray< uint8 > &  Result, const TCHAR *  Filename, uint32  Flags = 0  )

static

Load a binary file to a dynamic array with two uninitialized bytes at end as padding.

Parameters

Result	Receives the contents of the file
Filename	The file to read
Flags	Flags to pass to IFileManager::CreateFileReader

Load a binary file to a dynamic array with two uninitialized bytes at end as padding.

LoadFileToString() [1/3]

bool FFileHelper::LoadFileToString ( FString &  Result, const TCHAR *  Filename, EHashOptions  VerifyFlags = EHashOptions::None, uint32  ReadFlags = 0  )

static

Load a text file to an FString. Supports all combination of ANSI/Unicode files and platforms.

Parameters

Result	String representation of the loaded file
Filename	Name of the file to load
VerifyFlags	Flags controlling the hash verification behavior ( see EHashOptions )

Load a text file to an FString. Supports all combination of ANSI/Unicode files and platforms.

Parameters

Result	string representation of the loaded file
Filename	name of the file to load
VerifyFlags	flags controlling the hash verification behavior ( see EHashOptions )

LoadFileToString() [2/3]

bool FFileHelper::LoadFileToString ( FString &  Result, FArchive &  Reader, EHashOptions  VerifyFlags = EHashOptions::None  )

static

Loads a text file from an FArchive to an FString. Supports all combination of ANSI/Unicode files and platforms.

Parameters

Result	String representation of the loaded file
Reader	The archive to load from
VerifyFlags	Flags controlling the hash verification behavior ( see EHashOptions )

LoadFileToString() [3/3]

bool FFileHelper::LoadFileToString ( FString &  Result, IPlatformFile *  PlatformFile, const TCHAR *  Filename, EHashOptions  VerifyFlags = EHashOptions::None, uint32  ReadFlags = 0  )

static

Load a text file to an FString. Supports all combination of ANSI/Unicode files and platforms.

Parameters

Result	String representation of the loaded file
PlatformFile	PlatformFile interface to use
Filename	Name of the file to load
VerifyFlags	Flags controlling the hash verification behavior ( see EHashOptions )

LoadFileToStringArray() [1/2]

bool FFileHelper::LoadFileToStringArray ( TArray< FString > &  Result, const TCHAR *  Filename  )

static

Load a text file to an array of strings. Supports all combination of ANSI/Unicode files and platforms.

Parameters

Result	String representation of the loaded file
Filename	Name of the file to load

LoadFileToStringArray() [2/2]

bool FFileHelper::LoadFileToStringArray ( TArray< FString > &  Result, const TCHAR *  Filename, EHashOptions  VerifyFlags  )

static

LoadFileToStringArrayWithPredicate() [1/2]

bool FFileHelper::LoadFileToStringArrayWithPredicate ( TArray< FString > &  Result, const TCHAR *  Filename, TFunctionRef< bool(const FString &)>  Predicate  )

static

Load a text file to an array of strings, filtered by a user-defined predicate. Supports all combination of ANSI/Unicode files and platforms.

Parameters

Result	String representation of the loaded file
Filename	Name of the file to load
Predicate	Condition for whether or not to add the line to the array

LoadFileToStringArrayWithPredicate() [2/2]

bool FFileHelper::LoadFileToStringArrayWithPredicate ( TArray< FString > &  Result, const TCHAR *  Filename, TFunctionRef< bool(const FString &)>  Predicate, EHashOptions  VerifyFlags  )

static

LoadFileToStringWithLineVisitor()

bool FFileHelper::LoadFileToStringWithLineVisitor ( const TCHAR *  Filename, TFunctionRef< void(FStringView Line)>  Visitor  )

static

Load a text file and invoke a visitor for each line. Supports all combination of ANSI/Unicode files and platforms.

Parameters

Filename	Name of the file to load
Visitor	Visitor to invoke for each non-empty line in the file

SaveArrayToFile() [1/2]

bool FFileHelper::SaveArrayToFile ( const TArray64< uint8 > &  Array, const TCHAR *  Filename, IFileManager *  FileManager = &IFileManager::Get(), uint32  WriteFlags = 0  )

static

Save a binary array to a file.

SaveArrayToFile() [2/2]

bool FFileHelper::SaveArrayToFile ( TArrayView64< const uint8 >  Array, const TCHAR *  Filename, IFileManager *  FileManager = &IFileManager::Get(), uint32  WriteFlags = 0  )

static

Save a binary array to a file.

SaveStringArrayToFile()

bool FFileHelper::SaveStringArrayToFile ( const TArray< FString > &  Lines, const TCHAR *  Filename, EEncodingOptions  EncodingOptions = EEncodingOptions::AutoDetect, IFileManager *  FileManager = &IFileManager::Get(), uint32  WriteFlags = 0  )

static

Write the FString to a file. Supports all combination of ANSI/Unicode files and platforms.

SaveStringToFile()

bool FFileHelper::SaveStringToFile ( FStringView  String, const TCHAR *  Filename, EEncodingOptions  EncodingOptions = EEncodingOptions::AutoDetect, IFileManager *  FileManager = &IFileManager::Get(), uint32  WriteFlags = 0  )

static

Write the FString to a file. Supports all combination of ANSI/Unicode files and platforms.

UE_DEPRECATED()

enum FFileHelper::UE_DEPRECATED ( 5.  0, "EChannelMask has been deprecated in favor of EColorChannel"    )

inlinestrong

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The documentation for this struct was generated from the following files:

• Engine/Source/Runtime/Core/Public/Misc/FileHelper.h
• Engine/Source/Runtime/Core/Private/Misc/FileHelper.cpp