Linux

kill vs pkill

Both commands terminate processes but differ in how they identify targets:

kill

  • Requires process ID (PID)
  • Syntax: kill [options] <PID>
  • More precise targeting
  • Example: kill 1234

pkill

  • Accepts process name patterns
  • Syntax: pkill [options] <pattern>
  • Can target multiple processes at once
  • Example: pkill firefox

Key differences:

kill  → Targets by PID
pkill → Targets by name/pattern

Both support the same signal options (-9, -15, etc.) to specify how processes are terminated.

Common Signal Options

  • -1 (SIGHUP): Reload configuration
  • -2 (SIGINT): Interrupt (like Ctrl+C)
  • -9 (SIGKILL): Force kill, cannot be caught or ignored
  • -15 (SIGTERM): Graceful termination (default)
  • -18 (SIGCONT): Continue if stopped
  • -19 (SIGSTOP): Stop process execution