Load a Text File

Development Programming & Scripting C++
1

Hello,

i want to load a Textfile, i only know the Method with fstream

 std::ifstream ifs("C:\myfile.txt"); std::string content((std::istreambuf_iterator<char>(ifs)), (std::istreambuf_iterator<char>()));

But that doesn’t seem to work and i also need i need a FString.

How can i read a File and load it into a String?

Thanks
Greetings
Cybergebi

2

FFileHelper

You want FFileHelper.h !

Check it out in the Source code!

Here’s my code for saving a text file to hard disk

use this as reference for doing the reverse + FFileHelper.h

3

Thanks, really cool :slight_smile:

4

I have tryed your Code, but have a Problem

 FString CompleteFilePath = "G:\saves\map.txt";	if (!FPlatformFileManager::Get().GetPlatformFile().FileExists(*CompleteFilePath))	{	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, TEXT("Could not Find File"));	return;	} const int64 FileSize = FPlatformFileManager::Get().GetPlatformFile().FileSize(*CompleteFilePath);	//if not in player controller use UE_LOG. ClientMessages show up if you press ~ in-game	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, TEXT("File Size is:"));	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, FString::FromInt(FileSize));

i got Following Error:

 error C2220: warning treated as error - no object file generated

What should i do?

5

you should post more of your compile error :slight_smile:

6

Alrigh, here the Code:

 // Copyright 1998-2014 Epic Games, Inc. All Rights Reserved. #include "MyProjectThirdPersion.h" #include "SpawnHandler.h" #include "FileHelpers.h" ASpawnHandler::ASpawnHandler(const class FPostConstructInitializeProperties& PCIP)	: Super(PCIP) { } void ASpawnHandler::BeginPlay() {	Super::BeginPlay();	if (GEngine)	{	FString CompleteFilePath = "G:\saves\map.txt";	if (!FPlatformFileManager::Get().GetPlatformFile().FileExists(*CompleteFilePath))	{	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, TEXT("Could not Find File"));	return;	}	const int64 FileSize = FPlatformFileManager::Get().GetPlatformFile().FileSize(*CompleteFilePath);	//if not in player controller use UE_LOG. ClientMessages show up if you press ~ in-game	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, TEXT("File Size is:"));	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, FString::FromInt(FileSize));	} }

and the FULL Error

 Error	5	error : Failed to produce item: C:\Users\Cybergebi\Documents\Unreal Projects\MyProjectThirdPersion\Binaries\Win64\UE4Editor-MyProjectThirdPersion.pdb	C:\Users\Cybergebi\Documents\Unreal Projects\MyProjectThirdPersion\Intermediate\ProjectFiles\ERROR Error	2	error C2220: warning treated as error - no 'object' file generated	C:\Users\Cybergebi\Documents\Unreal Projects\MyProjectThirdPersion\Source\MyProjectThirdPersion\SpawnHandler.cpp: 19 Error	6	error MSB3073: The command "G:\UnrealEngine\Engine\Build\BatchFiles\Build.bat MyProjectThirdPersionEditor Win64 Development "C:\Users\Cybergebi\Documents\Unreal Projects\MyProjectThirdPersion\MyProjectThirdPersion.uproject"" exited with code -1.	C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.MakeFile.Targets:	38 Warning	1	warning : Was not able to delete temporary file created by Unreal Build Tool: H:\Local\Temp	mpD196.tmp.bat	C:\Users\Cybergebi\Documents\Unreal Projects\MyProjectThirdPersion\Intermediate\ProjectFiles\EXEC Warning	4	warning C4129: 'm' : unrecognized character escape sequence	C:\Users\Cybergebi\Documents\Unreal Projects\MyProjectThirdPersion\Source\MyProjectThirdPersion\SpawnHandler.cpp:	19 Warning	3	warning C4129: 's' : unrecognized character escape sequence	C:\Users\Cybergebi\Documents\Unreal Projects\MyProjectThirdPersion\Source\MyProjectThirdPersion\SpawnHandler.cpp:	19

Thanks for helping me :smiley:

7

Oh, i just found the Error by myself :smiley:

For others who are also Searching for a Solution, the Read Code :rolleyes:

 FString CompleteFilePath = "G:\\saves\\map.txt";	if (!FPlatformFileManager::Get().GetPlatformFile().FileExists(*CompleteFilePath))	{	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, TEXT("Could not Find File"));	return;	}	const int64 FileSize = FPlatformFileManager::Get().GetPlatformFile().FileSize(*CompleteFilePath);	//if not in player controller use UE_LOG. ClientMessages show up if you press ~ in-game	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, FString::FromInt(FileSize));	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Blue, TEXT("File Size is: (in kb)"));	FString FileData = "TEST";	FFileHelper::LoadFileToString(FileData, *CompleteFilePath);	GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, FileData);

Thanks for all

Greetings
Cybergebi

3 Likes
9

Works flawlessly. Thank you very much.

Here is the function I wrote to read a file from an absolute path :

FString UBPFL_FileIO::LoadFileToString(FString AbsolutePath) {	FString result = "NONE";	FFileHelper::LoadFileToString(result, *AbsolutePath); //Reads file content and puts it inside result return result; }