C++ programming language offers various useful and exciting features and functionalities to programmers. It also supports object-oriented programming. With the help of C++, you can also perform file handling. Files and streams are one of the most important and useful concepts in C++.<\/p>\n
Till now, we were using iostream<\/strong> which provides cin and cout methods for reading from input and writing to output respectively.<\/p>\n With the help of Files, you can store data in a storage device permanently. Using File Handling, you can store the output of a program in a file and you can also perform various operations on it. You can say that a stream is an abstraction that represents a device in which input and output operations are performed.<\/p>\n In C++, there are 3 file handling methods such as ifstream, ofstream and fstream. They are designed to manage the disk files. These are defined in fstream. That\u2019s why you have to include fstream whenever you are working with files in C++.<\/p>\n Files are mainly handled by three classes in C++:-<\/p>\n You can perform the below operations through File Handling:-<\/p>\n In C++, you can open a file using the following ways:-<\/p>\n To open a file, use<\/p>\n Syntax:-<\/strong><\/p>\n Following is the list of modes:-<\/p>\n Example:-<\/strong><\/p>\n In the above example, exp is an object of type fstream. As we said that fstream is a class so that\u2019s why we have to create an object of this class to use its member functions. We created an exp object and called the open() function. You can also combine different modes using pipe(|) or or.<\/p>\n With the help of stream insertion operator, you can write data to a file. And with the help of the stream extraction operator, you can read data from a file.<\/p>\n Example:- Using the open() function<\/strong><\/p>\n Output:-<\/strong><\/p>\n In the above, we created an object of the class fstream named exp. Then we apply the open() function on the created object. We used the if and else statement. If the file already exists or if it does not exist then it will print \u201cFile Creation failed!\u201d. Otherwise, it will create a new file named and it will print \u201cCreated a New File!\u201d to the screen.<\/p>\n You can also write data into a file in C++. Using stream insertion operator(<<), you can write data into a file in C++.<\/p>\n Example:- writing to a file<\/strong><\/p>\n Output:-<\/strong><\/p>\n Created a new file!<\/p>\n Name of the file:- Tech.txt In the above example, we created a new file named Tech.txt. We used the stream insertion operator(\u201c<<\u201d) to put data into that file. And the data is \u201cTechVidvan Tutorial: C++ File Handling!\u201d.<\/p>\n You can also read data from a file. Using the stream extraction operator(\u201c>>\u201d), you can read the contents of the file.<\/p>\n Example:- reading from a file<\/strong><\/p>\n Output:-<\/strong><\/p>\n In the above example, we are reading the contents of the Tech.txt file using the stream extraction operator. If the file does not exist then it will print No such file to the screen. You can see there are no spaces in the output. To correct it, you can use getline() with a character array to print the whole line as it is.<\/p>\n You can use C++ close() function to close a file.<\/p>\n Syntax:-<\/strong><\/p>\n Example:- Closing a file<\/strong><\/p>\n Output:-<\/strong><\/p>\n Below are some special functions which you can use with file streams:-<\/p>\n 1. tellp():<\/strong>– Used to tell the current position of the put pointer.<\/p>\n Syntax:-<\/strong> 2. tellg():<\/strong>– Used to tell the current position of the get pointer.<\/p>\n Syntax:-<\/strong> 3. seekp():<\/strong>– Used to move the put pointer to the mentioned location.<\/p>\n Syntax:-<\/strong> 4. seekg():<\/strong>– Used to move the get pointer(input) to a specified location.<\/p>\n Syntax:-<\/strong> 5. put():-<\/strong> Used to write a single character to the file.<\/p>\n 6. get():-<\/strong> Used to read a single character from the file.<\/p>\n Example:-<\/strong><\/p>\n Output:-<\/strong><\/p>\n In this tutorial, we discussed what is file handling and file handling methods in C++. We discussed how you can perform operations such as reading, opening, writing, and closing a file in C++.<\/p>\n","protected":false},"excerpt":{"rendered":" C++ programming language offers various useful and exciting features and functionalities to programmers. It also supports object-oriented programming. With the help of C++, you can also perform file handling. Files and streams are one...<\/p>\n","protected":false},"author":1,"featured_media":84646,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3405],"tags":[4267,3799,4268,4269,4270],"class_list":["post-84208","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cpp","tag-close-file-in-c","tag-file-handling-in-c","tag-file-handling-methods-in-c","tag-open-file-in-c","tag-write-file-in-c"],"yoast_head":"\nWhat is File Handling in C++?<\/h3>\n
\n
\n
Opening a file in C++<\/h3>\n
\n
open() function<\/pre>\n
void open(const char* NameFile,ios::openmode mode);\n<\/pre>\n
\n
\n\n
\n Modes<\/b><\/td>\n What it does<\/b><\/td>\n<\/tr>\n \n in<\/span><\/td>\n Used to open the file for reading<\/span><\/td>\n<\/tr>\n \n out<\/span><\/td>\n Used to open the file for writing<\/span><\/td>\n<\/tr>\n \n binary<\/span><\/td>\n Used to open the file in binary mode<\/span><\/td>\n<\/tr>\n \n app<\/span><\/td>\n Used to append all the outputs at the end by opening the file<\/span><\/td>\n<\/tr>\n \n ate<\/span><\/td>\n Used to move the control to the end of the file<\/span><\/td>\n<\/tr>\n \n trunc<\/span><\/td>\n Used to remove the data<\/span><\/td>\n<\/tr>\n \n nocreate<\/span><\/td>\n Used to open the file only if it exists<\/span><\/td>\n<\/tr>\n \n noreplace<\/span><\/td>\n Used to open the file only if it does not exist<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n fstream exp;\nexp.open(\"Tech.txt\", ios::out);\n<\/pre>\n
\nDefault Open modes:-<\/p>\n\n
#include<iostream>\n#include <fstream>\nusing namespace std;\nint main()\n{\nfstream exp;\nexp.open(\"Tech.txt\",ios::out); \nif(!exp)\n{\ncout<<\"File Creation failed!\";\n}\nelse\n{\ncout<<\"Created a New File!\";\nexp.close();\n}\nreturn 0;\n}\n<\/pre>\nWriting to a file in C++<\/h3>\n
#include <iostream>\n#include <fstream>\nusing namespace std;\nint main()\n{\nfstream exp;\nexp.open(\"Tech.txt\",ios::out); \nif(!exp)\n{\ncout<<\"File creation failed!\";\n}\nelse\n{\ncout<<\"Created a new file!\";\nexp<<\"TechVidvan Tutorial: C++ File Handling!\"; \nexp.close();\n} \nreturn 0;\n}\n<\/pre>\n
\nContents:- TechVidvan Tutorial: C++ File Handling!<\/p>\n<\/div>\nReading from a file in C++<\/h4>\n
#include <iostream>\n#include <fstream>\nusing namespace std;\nint main()\n{\nfstream exp;\nexp.open(\"Tech.txt\",ios::in); \nif(!exp)\ncout<<\"No such file\"; } else { char s; while (!exp.eof()) { exp >>s;\ncout << s; \n}\nexp.close(); \nreturn 0;\n}\n<\/pre>\nClose a file in C++:-<\/h3>\n
File Pointer.close()\n<\/pre>\n
#include <iostream>\n#include <fstream>\nusing namespace std;\nint main()\n{\nfstream exp;\nexp.open(\"Tech.txt\",ios::out); \nexp.close(); \nreturn 0;\n}\n<\/pre>\nSpecial Operations on a file in C++<\/h3>\n
\nfilepointer.tellp()<\/p>\n
\nfilepointer.tellg()<\/p>\n
\nfilepointer.seekp(number_of_bytes,reference_mode)<\/p>\n
\nfilepointer.seekg(number_of_bytes,reference_point)<\/p>\n#include <iostream>\n#include<conio>\n#include <fstream>\n\nusing namespace std;\n\nint main()\n{\n fstream exp;\n exp.open(\"E:\\Tech.txt\",ios::out);\n if(!exp)\n {\n \tcout<<\"File creation failed\";\n }\n else\n {\n \tcout<<\"New file created\"<<endl;\n \texp<<\"TechVidvan Tutorial!\";\n \tcout<<\"File Pointer Position: \"<<exp.tellp()<<endl; \n \t \n \texp.seekp(-1, ios::cur);\n \tcout<<\"tellp=>File Pointer Position: \"<<exp.tellp()<<endl;\n \t \n \texp.close();\n }\n exp.open(\"E:\\Tech.txt\",ios::in); \n if(!exp)\n {\n \tcout<<\"No such file\";\n }\n else\n {\n \tchar s;\n \texp.seekg(5, ios::beg); \n \tcout<<\"tellg=>File Pointer Position: \"<<exp.tellg()<<endl;\n \tcout<<endl;\n \texp.seekg(1, ios::cur);\n \tcout<<\"tellg=>File Pointer Position: \"<<exp.tellg()<<endl; \/\n \texp.close(); \/\/Closing file\n }\n getch();\n return 0;\n}\n<\/pre>\n
\nFile Pointer Position: 20
\ntellp=>File Pointer Position: 19
\ntellg=>File Pointer Position: 5
\ntellg=>File Pointer Position: 6<\/div>\nSummary<\/h3>\n