in a blueprintFunctionLibrary, you can save a string in a txt file like this:
.h
#include "Engine.h"
...
UFUNCTION(BlueprintCallable, Category = "Save")
static bool FileSaveString(FString SaveTextB, FString FileNameB);
UFUNCTION(BlueprintPure, Category = "Save")
static bool FileLoadString(FString FileNameA, FString& SaveTextA);
.cpp
bool UOmniBlueprintFunctionLibrary::FileSaveString(FString SaveTextB, FString FileNameB)
{
return FFileHelper::SaveStringToFile(SaveTextB, *(FPaths::GameDir() + FileNameB));
}
bool UOmniBlueprintFunctionLibrary::FileLoadString(FString FileNameA, FString& SaveTextA)
{
return FFileHelper::LoadFileToString(SaveTextA, *(FPaths::GameDir() + FileNameA));
}
saving as a .csv is the same as a text file, you just separate the values by commas in a concatenated string, and save it with a .csv extension