16.2、信號捕捉
方法一:#man 7 signal
方法二:#kill -l
方法三:#trap -l
2、常用信號列表
Signal Value Action Comment ────────────────────────────────────────────────────────────────────── SIGHUP 1 Term Hangup detected on controlling terminal or death of controlling process SIGINT 2 Term Interrupt from keyboard SIGQUIT 3 Core Quit from keyboard SIGILL 4 Core Illegal Instruction SIGABRT 6 Core Abort signal from abort(3) SIGFPE 8 Core Floating point exception SIGKILL 9 Term Kill signal SIGSEGV 11 Core Invalid memory reference SIGPIPE 13 Term Broken pipe: write to pipe with no readers SIGALRM 14 Term Timer signal from alarm(2) SIGTERM 15 Term Termination signal SIGUSR1 30,10,16 Term User-defined signal 1 SIGUSR2 31,12,17 Term User-defined signal 2 SIGCHLD 20,17,18 Ign Child stopped or terminated SIGCONT 19,18,25 Cont Continue if stopped SIGSTOP 17,19,23 Stop Stop process SIGTSTP 18,20,24 Stop Stop typed at terminal SIGTTIN 21,21,26 Stop Terminal input for background process SIGTTOU 22,22,27 Stop Terminal output for background process |
3、trap:捕捉信號,
它不能捕捉9號信號(SIGKILL)和15號信號(SIGTERM),一般常用的捕捉信號是HUP和INT信號。
可以自定義捕捉信號後的處理方法
4、trap命令用法:
格式:trap 'command ' signal //command為捕捉信號後要執行的命令或腳本或函數,多個命令之間用分號(;)隔開;signal為要捕捉的信號
示例1:
[root@localhost sh]# cat tr.sh
#!/bin/bash
trap 'echo "quit";exit' INT //一般把trap寫在最上面,多個command之間用分號(;)隔開,
for i in {1..10};do
ping -W 1 -c 1 192.168.0.$i
done
[root@localhost sh]#
示例二:
16.2、信號捕捉