{"id":14786,"date":"2023-03-22T12:16:30","date_gmt":"2023-03-22T12:16:30","guid":{"rendered":"https:\/\/www.prepbytes.com\/blog\/?p=14786"},"modified":"2023-07-02T18:34:53","modified_gmt":"2023-07-02T18:34:53","slug":"random-access-file-in-c","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/random-access-file-in-c\/","title":{"rendered":"Random Access File in C"},"content":{"rendered":"

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The C programming language offers a variety of functions that enable working with random access file in C, which grant programmers the ability to read from or write to any position within the file. This article will delve deeper into the concept of random access file in C and explore its functionalities.<\/p>\n

What are Files?<\/h2>\n

In programming languages, files are utilized for long-term data storage or data transfer purposes. The method of accessing a file varies depending on the type of file system employed to retrieve data stored within the file.<\/p>\n

Types of Files<\/h2>\n

Sequential files and random access files are two common ways of organizing data in computer systems.<\/p>\n

Sequential file:<\/h3>\n

Sequential file is a type of file organization in which data is stored in a continuous manner, one record after the other, and each record is accessed in sequence. In a sequential file, data is read from the beginning of the file and is processed in the order it appears in the file. This type of file is best suited for applications where data is processed sequentially and not randomly accessed.<\/p>\n

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Random Access file:<\/h3>\n

In C language, a random access file allows us to read or write any data in our disc file without reading or writing every piece of data before it. We can quickly search for data, edit it, or even delete it in a random-access file. We can open and close random access files in C using the same opening mode as sequential files, but we need a few new functions to access files randomly.<\/p>\n

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Functions in random access file:<\/h2>\n

Thus, the following three functions assist in accessing the random access file in C:<\/p>\n

    \n
  1. ftell()<\/li>\n
  2. fseek()<\/li>\n
  3. rewind()<\/li>\n<\/ol>\n

    1. ftell():<\/h3>\n

    It is a standard C library function used to get the current position of the file pointer in a random access file. The function takes a file pointer as its argument and returns the current position of the file pointer, representing the number of bytes from the beginning of the file.<\/p>\n

    Syntax for ftell():<\/strong><\/p>\n

    pos=ftell(FILE *fp)<\/code><\/pre>\n
    Explanation of Syntax for ftell():<\/strong>
    \nWhere pos contain the current position or the number of bytes read, and fp is a file pointer.<\/p>\n
    Example for ftell():<\/strong><\/p>\n\t\t\t\t\t\t