Overview of File Handling
File is a set of records that can be accessed through the set of library functions.
A file represents a sequence of bytes, does not matter if it is a text file or binary file.
C programming language provides access on high level functions as well as low level call to handle file on your storage device.
Types of File
There are two tyoes of files.
Sequential File: In this tyoe datas are kept sequentially. If we want to read the last record of the file we need to read all the records before that record. It takes more time.
Random Access File: In this type data can be read and modified randomly. In this type if we want to read the last records of file, we can read it directly. It takes less time as compared to sequential file.
There are different operations that can be carried out on a file. These are:
|fopen()||create a new file or open a existing file|
|fclose()||closes a file|
|getc()||reads a character from a file|
|putc()||writes a character to a file|
|fscanf()||reads a set of data from a file|
|fprintf()||writes a set of data to a file|
|getw()||reads a integer from a file|
|putw()||writes a integer to a file|
|fseek()||set the position to desire point|
|ftell()||gives current position in the file|
|rewind()||set the position to the begining point|
|feof()||Detects the end of file.|
|ftell()||Returns the current pointer position.|
|rename()||Changes the name of file.|
Opening a File:- A file has to be opened before beginning of read and write operations. Opening of file creates a link between to operating system and the file functions. Opening a file is performed using library function fopen( ).
The syntax for opening file in standard I/O is:
FILE * ptr; ptr = fopen("file_name","mode")
|r||opens a text file in reading mode|
|w||opens or create a text file in writing mode.|
|a||opens a text file in append mode|
|r+||opens a text file in both reading and writing mode|
|w+||opens a text file in both reading and writing mode|
|a+||opens a text file in both reading and writing mode|
|rb||opens a binary file in reading mode|
|wb||opens or create a binary file in writing mode|
|ab||opens a binary file in append mode|
|rb+||opens a binary file in both reading and writing mode|
|wb+||opens a binary file in both reading and writing mode|
|ab+||opens a binary file in both reading and writing mode|
Closing a File:- To close a file, use the fclose(). The prototype of this function is :
The fclose() returns zero on success, or EOF if there is an error in closing the file.