POSIX Kill Signals & Process Simulator

In Linux, processes communicate and manage shutdowns using signals. Sending the wrong signal (like immediately executing kill -9) can corrupt database records or leak open network port locks.

Use this interactive simulator to study how system processes react to different Unix signals and build correct command structures.

Interactive Process & Signal Simulator

Select a target process from the active grid, choose a signal to transmit, and click [ TRANSMIT SIGNAL ] to watch the behavior.

[ ACTIVE PROCESS MONITOR ]

Process stderr / Console Log:

[ TRANSMIT SIGNAL ]

Select Unix Signal:

SIGTERM (15) - Graceful exit request SIGKILL (9) - Brutal force termination SIGHUP (1) - Reload configs file SIGSTOP (19) - Pause execution SIGCONT (18) - Resume execution

[ COMPILED TERMINAL COMMAND ]

--- ### Core Signal Types Explained * **`SIGTERM (15)` (Termination):** The polite way to stop a program. It requests the app to terminate, allowing it to catch the signal, flush database buffers, close network sockets, and clean up temp files. * **`SIGKILL (9)` (Kill):** The brutal way. It is handled directly by the kernel, not the app. The app is killed immediately without any chance to clean up, which can cause file corruption. * **`SIGHUP (1)` (Hangup):** Historically sent when a serial connection hung up. Today, daemon apps (like Nginx) catch it and reload their configuration file without restarting the main process.