System call in linux by C
1: #include <stdlib.h>
2: int system(const char *command);
3:
4: while (something) {
5: int ret = system("foo");
6: if (WIFSIGNALED(ret) &&
7: (WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))
8: break;
9: }
宏定义
含义
WIFEXITED(status)
如果进程通过系统调用_exit或函数调用exit正常退出,该宏的值为真。
WIFSIGNALED(status)
如果子进程由于得到的信号(signal)没有被捕捉而导致退出时,该宏的值为真。
WIFSTOPPED(status)
如果子进程没有终止,但停止了并可以重新执行时,该宏返回真。这种情况仅出现在waitpid调用中使用了WUNTRACED选项。
WEXITSTATUS(status)
如果WIFEXITED(status)返回真,该宏返回由子进程调用_exit(status)或exit(status)时设置的调用参数status值。
WTERMSIG(status)
如果WIFSIGNALED(status)返回为真,该宏返回导致子进程退出的信号(signal)的值。
WSTOPSIG(status)
如果WIFSTOPPED(status)返回真,该宏返回导致子进程停止的信号(signal)值。
Termination Signals
The
SIGINT
(“program interrupt”) signal is sent when the user types the INTR character (normally C-c). See Special Characters, for information about terminal driver support for C-c.
The
SIGQUIT
signal is similar toSIGINT
, except that it's controlled by a different key—the QUIT character, usually C-\—and produces a core dump when it terminates the process, just like a program error signal. You can think of this as a program error condition “detected” by the user.