File management operating system

A file is a collection of correlated information which is recorded on secondary or non-volatile storage like magnetic disks, optical disks, and tapes. It is a method of data collection that is used as a medium for giving input and receiving output from that program.

In general, a file is a sequence of bits, bytes, or records whose meaning is defined by the file creator and user. Every File has a logical location where they are located for storage and retrieval. A File Structure needs to be predefined format in such a way that an operating system understands.

It has an exclusively defined structure, which is based on its type. Reading Suggestion:- What is Operating System? A file has a name and data. Moreover, it also stores meta information like file creation date and time, current size, last modified date, etc. All this information is called the attributes of a file system. It refers to the ability of the operating system to differentiate various types of files like text files, binary, and source files.

It is a hardware file that reads or writes data character by character, like mouse, printer, and more. Collection of related data is called a database. Relationships among elements of data are explicit. A Record type is a complex data type that allows the programmer to create a new data type with the desired column structure. Its groups one or more columns to form a new data type. Then the entry for the new file must be made in the directory.

This entry should contain information about the file such as its name, its location etc. To read from a file, the system call should specify the name and location of the file. There should be a read pointer at the location where the read should take place. After the read process is done, the read pointer should be updated.

To write into a file, the system call should specify the name of the file and the contents that need to be written. There should be a write pointer at the location where the write should take place. After the write process is done, the write pointer should be updated. The file should be found in the directory to delete it.

After that all the file space is deleted so it can be reused by other files. This is also known as file seek. To reposition a file, the current file value is set to the appropriate entry. This deletes the data from the file without destroying all its attributes.

Only the file length is reset to zero and the file contents are erased. The rest of the attributes remain the same. The system identifies every file by its name and a unique identification number called inode number.

The inode number refers to the physical file, the data stored in a particular location. Above all, it also maintains other sets of attributes associated with the file. There are different types of file systems a system may support. Some of which are mentioned below type of file system that an operating system supports are:. A user or the system can perform different operations on the files.

It depends on the permission assigned to the file. Different operations that can be performed on the file are:.

A common technique for implementing file types is to include the type as part of the file name. The system uses the extension to indicate the type of the file and the type of operations that can be done on that file.

Various file types are executable, object, source code, batch, text, archive, etc. A File Structure of a file is a predefined format in which the operating system understands. It has an exclusively defined structure, which is based on its type. The files must follow a required structure that is understood by the operating system. On the other hand, if the operating system supports multiple file structures, the size of the kernel will increase. For instance, an operating system defines five different file structures, the kernel needs to have the code to support these file structures.

Different operating systems support different file structures according to the type of file. For instance,. Files store information. When required, this information must be accessed and read into computer memory. Some systems use only one type of access method, others might use many of them. Generally, a file in the system can be accessed using two ways:. There are a number of files that reside in the system. The directory records information -such as name, location, size, and type-for all files on a volume.

A directory is viewed as a symbol table which can be organized in many ways. To understand how files are stored in the directory, we need to know what is the logical structure of the directory system.

When considering the directory structure, we need to keep in mind what different operations that can be performed on a directory like:. The single-level directory is the simplest directory structure. All the files are stored in the same directory which is easy to understand. However, there are some limitations to this directory structure.