Windows anonymous pipes are actually Ordinary pipes, and they behave similarly to their UNIX counterparts: they are unidirectional and employ parent-child relationships between the communicating processes. In addition, reading and writing to the pipe can be accomplished with the ordinary ReadFile() and WriteFile() functions. The Windows API use CreatePipe() function for creating pipes, which is passed four parameters. The parameters provide separate handles forreading andwriting to the pipeAn instance of the STARTUPINFO structure, used to specify that the child process is to inherit the handles of the pipe.the size (in Bytes) of the pipe may be specified.Windows requires the programmer ... Read More

There is no whoami function in MySQL. The whoami can be used to know the current user in UNIX. Use user() or current_user() function from MySQL for the same purpose.The following is the output.+-----------+ | version() | +-----------+ | 8.0.12    | +-----------+ 1 row in set (0.00 sec)Case 1  −Using CURRENT_USER() function.The query to know the current user is as follows.mysql> select current_user();The following is the output.+----------------+ | current_user() | +----------------+ | root@%         | +----------------+ 1 row in set (0.00 sec)Case 2 − Using USER() function.The query is as follows −mysql> select user();The following is ... Read More

Process synchronization in Linux involves providing a time slice for each process so that they get the required time for execution.The process can be created using the fork() command in Linux. The creating process is called the parent process and the created process is the child process. A child process can have only one parent but a parent process may have many children. Both the parent and child processes have the same memory image, open files and environment strings. However, they have distinct address spaces.A diagram that demonstrates the fork() command is given as follows −Orphan ProcessesThere are some processes ... Read More

The shell is the command interpreter on the Linux systems. It the program that interacts with the users in the terminal emulation window. Shell commands are instructions that instruct the system to do some action.Some of the commonly used shell commands are −basenameThis command strips the directory and suffix from filenames. It prints the name of the file with all the leading directory components removed. It also removes a trailing suffix if it is specified.Example of basename is as follows −$ basename country/city.txtThis gets the name of the file i.e. city which is present in folder country.city.txtcatThis command concatenates and ... Read More

The interface between a process and an operating system is provided by system calls. In general, system calls are available as assembly language instructions. They are also included in the manuals used by the assembly level programmers.System calls are usually made when a process in user mode requires access to a resource. Then it requests the kernel to provide the resource via a system call.Types of System CallsThere are mainly five types of system calls. These are explained in detail as follows −Here are the types of system calls −Process ControlThese system calls deal with processes such as process creation, ... Read More

Loadable kernel modules in an operating system is an object file that contains code to extend the running kernel, which is also known as the base kernel. The loadable kernel modules are used to add support for file systems, hardware, system calls etc.A figure that shows the loadable modules of the operating system is as follows −Advantage of Loadable Kernel ModulesAn operating system would have to include all the systems that provided all anticipated functionalities in the base kernel if there were no loadable modules. This would lead to wastage of memory as most of those systems would not be ... Read More

The Linux kernel modules can be loaded or removed from the kernel as required. This can be done without recompiling the kernel or rebooting the system and it enhances the functionality of the system.Without the kernel modules, the operating system would have to include all the systems that provide all anticipated functionalities in the base kernel. This would lead to wastage of memory as most of those systems would not be used often. Also, the users would need to rebuild and reboot the base kernel every time they would require a new functionality.The kernel modules have a .ko extension and ... Read More

The interface between a process and an operating system is provided by system calls. In general, system calls are available as assembly language instructions. They are also included in the manuals used by the assembly level programmers. System calls are usually made when a process in user mode requires access to a resource. Then it requests the kernel to provide the resource via a system call.A figure representing the execution of the system call is given as follows −As can be seen from this diagram, the processes execute normally in the user mode until a system call interrupts this. Then ... Read More

Solaris is a Unix based operating system that was developed by Sun Microsystems and after its acquisition by Oracle, it is known as Oracle Solaris. It is known for its scalability and its innovative features such as DTrace, ZFS, Time Slider etc. Solaris is a microkernel design and it is not possible to create a monolithic Solaris kernel.A diagram demonstrating the structure of the Solaris operating system is as follows −The different components in the Solaris operating system structure are −HardwareThis includes the physical components of the computer system such as monitor, keyboard, data storage etc.I/O BufferI/O devices are very ... Read More

The interface between a process and an operating system is provided by system calls. In general, system calls are available as assembly language instructions. They are also included in the manuals used by the assembly level programmers.Unix System CallsSystem calls in Unix are used for file system control, process control, interprocess communication etc. Access to the Unix kernel is only available through these system calls. Generally, system calls are similar to function calls, the only difference is that they remove the control from the user process.There are around 80 system calls in the Unix interface currently. Details about some of ... Read More