C files I/O functions handles data on secondary storage device, such as a hard disk.
C can handle files as Stream-oriented data (Text) files and System oriented data (Binary) files.
| Stream oriented data files | The data is stored in same manner as it appears on the screen. The I/O operations like buffering, data conversions etc. take place automatically. |
| System oriented data files | System-oriented data files are more closely associated with the OS and data stored in memory without converting into text format. |
C File Operations
There are five major operations that can be performed on a file are:
- Creation of a new file.
- Opening an existing file.
- Reading data from a file.
- Writing data in a file.
- Closing a file.
Steps for Processing a File
- Declare a file pointer variable.
- Open a file using fopen() function.
- Process the file using suitable function.
- Close the file using fclose() function.
To handling files in C, file input/output functions available in the stdio library are:
| Function | Uses/Purpose |
|---|---|
| fopen | Opens a file. |
| fclose | Closes a file. |
| getc | Reads a character from a file |
| putc | Writes a character to a file |
| getw | Read integer |
| putw | Write integer |
| fprintf | Prints formatted output to a file |
| fscanf | Reads formatted input from a file |
| fgets | Read string of characters from file |
| fputs | Write string of characters to file |
| feof | Detects end-of-file marker in a file |