kill 和 kill -9

kill – send a signal to a process

明朗了，其实kill就是给某个进程id发送了一个信号。默认发送的信号是SIGTERM，而kill -9发送的信号是SIGKILL，即exit。exit信号不会被系统阻塞，所以kill -9能顺利杀掉进程。当然你也可以使用kill发送其他信号给进程。
经常使用的killall呢？

killall – kill processes by name

即，通过指定进程名的方式杀死进程。

KILL(1) Linux User’s Manual KILL(1)
NAME
    kill - send a signal to a process
SYNOPSIS
    kill [ -signal | -s signal ] pid …
    kill [ -L | -V, --version ]
    kill -l [ signal ]
DESCRIPTION

• The default signal for kill is TERM. Use -l or -L to list avail‐
  able signals. Particularly useful signals include HUP, INT,
  KILL, STOP, CONT, and 0. Alternate signals may be specified in
  three ways: -9 -SIGKILL -KILL. Negative PID values may be used
  to choose whole process groups; see the PGID column in ps command
  output. A PID of -1 is special; it indicates all processes except
  the kill process itself and init.

SIGNALS

• The signals listed below may be available for use with kill.
  When known constant, numbers and default behavior are shown.

• Name Num Action Description
  0 0 n/a exit code indicates if a signal may be sent
  ALRM 14 exit
  HUP 1 exit
  INT 2 exit
  KILL 9 exit cannot be blocked
  PIPE 13 exit
  POLL exit
  PROF exit
  TERM 15 exit
  USR1 exit
  USR2 exit
  VTALRM exit
  STKFLT exit might not be implemented
  PWR ignore might exit on some systems
  WINCH ignore
  CHLD ignore
  URG ignore
  TSTP stop might interact with the shell
  TTIN stop might interact with the shell
  TTOU stop might interact with the shell
  STOP stop cannot be blocked
  CONT restart continue if stopped, otherwise ignore
  ABRT 6 core
  FPE 8 core
  ILL 4 core
  QUIT 3 core
  SEGV 11 core
  TRAP 5 core
  SYS core might not be implemented
  EMT core might not be implemented
  BUS core core dump might fail
  XCPU core core dump might fail
  XFSZ core core dump might fail

NOTES

• Your shell (command line interpreter) may have a built-in kill
  command. You may need to run the command described here as
  /bin/kill to solve the conflict.

EXAMPLES

• kill -9 -1
  • Kill all processes you can kill.
• kill -l 11
  • Translate number 11 into a signal name.
• kill -L
  • List the available signal choices in a nice table.
• kill 123 543 2341 3453
  • Send the default signal, SIGTERM, to all those processes.

SEE ALSO

• pkill(1), skill(1), kill(2), renice(1), nice(1), signal(7), kil‐
  lall(1).

STANDARDS

• This command meets appropriate standards. The -L flag is Linux-
  specific.

AUTHOR

• Albert Cahalan albert@users.sf.net wrote kill in 1999 to
  replace a bsdutils one that was not standards compliant. The
  util-linux one might also work correctly.
  Please send bug reports to procps-feedback@lists.sf.net
  Linux November 21, 1999 KILL(1)

kill -l

1. SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP
2. SIGABRT 7) SIGBUS 8) SIGFPE 9) SIGKILL 10) SIGUSR1
3. SIGSEGV 12) SIGUSR2 13) SIGPIPE 14) SIGALRM 15) SIGTERM
4. SIGSTKFLT 17) SIGCHLD 18) SIGCONT 19) SIGSTOP 20) SIGTSTP
5. SIGTTIN 22) SIGTTOU 23) SIGURG 24) SIGXCPU 25) SIGXFSZ
6. SIGVTALRM 27) SIGPROF 28) SIGWINCH 29) SIGIO 30) SIGPWR
7. SIGSYS 34) SIGRTMIN 35) SIGRTMIN+1 36) SIGRTMIN+2 37) SIGRTMIN+3
8. SIGRTMIN+4 39) SIGRTMIN+5 40) SIGRTMIN+6 41) SIGRTMIN+7 42) SIGRTMIN+8
9. SIGRTMIN+9 44) SIGRTMIN+10 45) SIGRTMIN+11 46) SIGRTMIN+12 47) SIGRTMIN+13
10. SIGRTMIN+14 49) SIGRTMIN+15 50) SIGRTMAX-14 51) SIGRTMAX-13 52) SIGRTMAX-12
11. SIGRTMAX-11 54) SIGRTMAX-10 55) SIGRTMAX-9 56) SIGRTMAX-8 57) SIGRTMAX-7
12. SIGRTMAX-6 59) SIGRTMAX-5 60) SIGRTMAX-4 61) SIGRTMAX-3 62) SIGRTMAX-2
13. SIGRTMAX-1 64) SIGRTMAX

---

本文来自 帝都码农 的优快云 博客 ，全文地址请点击：https://blog.youkuaiyun.com/rheostat/article/details/8089256?utm_source=copy