Signal (IPC)
lastmod 2026-11-10created 2022-11-012 edits
Signal is a limited form of inter-process communication (IPC) in Unix-like operating systems that notifies a process of an event asynchronously. When a numbered signal such as SIGINT, SIGTERM, SIGKILL, SIGSEGV, or SIGCHLD is sent by the kernel or with kill, the process performs the default action, runs a handler registered with sigaction, or ignores it. Inside a handler, only async-signal-safe functions may be called.