The function fopen() will return a file stream pointer pointing to the target file if the file opening was successful, which means if the file has existed in the first place, else will return the value NULL in case of fopen() was unable to open the file, meaning if the file has not existed. After fopen() has been executed, we are storing the return value of the execution in the pointer file.Starting from the main() function, we are creating a pointer of the FILE class or simply a FILE pointer to read the file, after that, we are calling the fopen() function with "test2.txt" and "r" as parameters, specifying the target file we want to work on, and the operation we want to carry on that, here the operation is "r" ie.Note - In my present workspace, the file "test2.txt" is not present. In the below example, we will be checking if a file exists or not using the fopen() function defined inside the fstream header file. open("./parent.txt"), and the program will work as it should, it will print the success message if the file was found there at the provided path, else will print the error message. For example - let's say there is a file named "parent.txt" present in the parent folder of the current working directory, then we can give the path as file. Remember - We can even give the path of the files which are present in some else directory. Then we are checking if the file object has opened the file or not using the if-else conditional statements, if the file was opened, meaning it exists on the provided path, hence printing the success message, else printing the error message.What this line does is, it will attempt to open the "test.txt" file in the read mode, now a file can only be opened if it is present there, we can not open a file that does not exist, so indirectly, here we are checking the existence of the file using the open() function.Starting from the main() function, we are creating an ifstream class object named file to read the target file later, then after we are calling the open function on the file object with the target file name as the parameter.Note - In my present workspace the file "test.txt" exists, if we write the name of a file that is not present, then the program will output accordingly. In this example, we will be checking if a file exists or not using the open() function defined inside the fstream header file. Using open() Function with ifstream Object Let's now discuss some of the ways through which we can check if a file exists or not in C++ 1. In this article, we will be understanding the various ways through which we can check for the existence of a file.įor example - checking if a file exists or not using the fopen() function, using the ifstream().open() function, etc, then after we will also be writing our custom definitions of a function apart from these pre-defined functions to check for the existence of a file. Whenever we want to do some work involving files, let's say backing up some already existing files, modifying the contents of some file, reading any system or user-created file, or something else too, we first need to be sure that the file exists. Files are entities that are used to store data in our systems.
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