Supported Signals

March 8, 2026 · View on GitHub

killport supports the following signals via the -s, --signal flag. The default is SIGKILL.

Gentle Signals

These signals can generally be caught and handled by processes for graceful shutdown.

Signal	Description
`SIGTERM`	Termination signal (graceful shutdown)
`SIGINT`	Interrupt from keyboard (Ctrl+C)
`SIGHUP`	Hangup — terminal closed or parent process died
`SIGUSR1`	User-defined signal 1
`SIGUSR2`	User-defined signal 2
`SIGCONT`	Continue if stopped
`SIGALRM`	Timer signal
`SIGVTALRM`	Virtual timer expired
`SIGPROF`	Profiling timer expired
`SIGWINCH`	Window size change
`SIGURG`	Urgent condition on socket
`SIGCHLD`	Child status has changed
`SIGIO`	I/O now possible
`SIGPIPE`	Broken pipe (write to pipe with no readers)
`SIGPWR`	Power failure
`SIGSYS`	Bad argument to routine

These signals are harder to handle and often terminate the process abruptly or produce a core dump.

Signal	Description
`SIGQUIT`	Quit from keyboard and dump core
`SIGABRT`	Abort signal from `abort()`
`SIGTSTP`	Stop typed at terminal
`SIGTTIN`	Terminal input for background process
`SIGTTOU`	Terminal output for background process
`SIGSTOP`	Stop process (cannot be caught)
`SIGSEGV`	Invalid memory reference
`SIGBUS`	Bus error (bad memory access)
`SIGFPE`	Floating-point exception
`SIGILL`	Illegal instruction
`SIGTRAP`	Trace/breakpoint trap

Cannot be caught or ignored.

Signal	Description
`SIGKILL`	Kill signal — immediate, unconditional termination

# Graceful termination
killport -s sigterm 8080

# Immediate kill (default)
killport -s sigkill 8080

# Interrupt
killport -s sigint 8080

Note: Signal availability varies by platform. Not all signals are available on Windows.