What is file handling in C?
Table of Contents
Introduction
File handling in C is a fundamental concept that allows a program to store data in files and retrieve it when needed. Unlike data stored in variables, which is lost when the program ends, files enable persistent storage, allowing data to be saved and accessed even after the program terminates. In C, file handling is done through a set of standard library functions, providing a way to create, open, read, write, and close files.
File Handling Functions in C
Opening a File with fopen()
The fopen() function is used to open a file in a specified mode (e.g., reading, writing). It returns a pointer to a FILE object, which is used to interact with the file in subsequent operations.
Syntax:
Example:
Reading from a File with fread() and fgets()
To read data from a file, C provides several functions like fread() for binary files and fgets() for reading strings from text files.
Example: Reading a String Using fgets():
Example: Reading Binary Data Using fread():
Writing to a File with fwrite() and fprintf()
To write data to a file, fwrite() is used for binary files, while fprintf() is used for writing formatted text.
Example: Writing a String Using fprintf():
Example: Writing Binary Data Using fwrite():
Closing a File with fclose()
Once all file operations are complete, it's important to close the file using fclose() to free resources and ensure that all data is properly written to the file.
Example:
Practical Examples
Example 1: Copying Contents from One File to Another
This example demonstrates how to copy the contents of one text file to another.
Example2: Appending Data to a File
Appending data to an existing file can be done using the "a" mode in fopen().
Conclusion
File handling in C is an essential skill for any programmer, enabling the creation, manipulation, and persistence of data through files. With functions like fopen(), fread(), fwrite(), and fclose(), you can perform a wide range of file operations, from simple text file reading and writing to complex binary data manipulation. Mastering file handling is crucial for building robust C applications that require data storage and retrieval.