由专门函数处理相应的信号
Bourne、bash和Korn Shell允许你按照以下方式处理进入程序的信号、忽略信号或者为特定的信号指定特定的行为，以及重置信号的默认行为，C和TC Shell被限制只能处理中断字符^C(Control-C).
表1.2显示的是进程可以使用的标准信号。
表1.2 标准信号
| Number | Name | 描述 | 对进程的作用 |
| 0 | EXIT | shell exits | termination |
| 1 | SIGHUP | terminal has disconnected | termination |
| 2 | SIGINT | user pressess Controc-C | termination |
| 3 | SIGQUIT | user presses Control-\ | termination |
| 4 | SIGILL | illegal hardware instruction | program error |
| 5 | SIGTRAP | produced by debugger | program error |
| 8 | SIGFPE | arithmetic error;e.g.,division by zero | program error |
| 9 | SIGKILL | cannot be caught or ignored | termination |
| 10 | SIGUSR1 | application-defined signal for user | |
| 11 | SIGSEGV | invalid memory references | program error |
| 12 | SIGUSR2 | application-defined signal for user | |
| 13 | SIGPIPE | broken pipe conncetion | operator error |
| 14 | SIGALRM | time-out | alarm sent |
| 15 | SIGTERM | termunation of a program | termination |
| 17 | SIGCHLD | child process has stopped or died | ignored |
| 18 | SIGCONT | starts a stopped job;can't be handled or ignored | continue if stopped |
| 19 | SIGSTOP | stops a job;can't be handled or ignored | stops the process |
| 20 | SIGSTP | interactive stop;user presses Control-z | stops the process |
| 21 | SIGTTIN | a background job is trying to read from the controlling terminal | stops the process |
| 22 | SIGTTOU | a background job is trying to write to the controlling terminal | stops the process |
