Correct spelling for the English word "SIGUSR" is [sˈɪɡʌsə], [sˈɪɡʌsə], [s_ˈɪ_ɡ_ʌ_s_ə] (IPA phonetic alphabet).
SIGUSR is a special signal that stands for "user-defined signal" in computing. It is a type of signal that can be sent to a process by the operating system or another process in order to request some action or notify the process about an event.
In Unix-like operating systems, including Linux, SIGUSR is a signal number used to indicate user-defined signals. Unlike standard signals like SIGINT (interrupt) or SIGTERM (termination), SIGUSR is not reserved for specific purposes by the operating system. Instead, it is left for developers to define and use for their own application-specific functionality.
SIGUSR can be raised using the kill command or through system calls in programming languages such as C or C++. Upon receiving a SIGUSR signal, a process can choose to handle it in a custom manner. This allows programmers to create their own signaling mechanism to communicate between processes or within a single process.
Furthermore, the SIGUSR signal has two variants: SIGUSR1 and SIGUSR2. These are typically used to differentiate between different user-defined signals or events. By capturing and responding to SIGUSR signals, developers can create custom functionalities, such as triggering specific actions, changing modes, or initiating communication between different components of an application.
Overall, SIGUSR signals provide a flexible means for developers to create and utilize their own custom signals to enhance the functionality and interactivity of their applications.