一个signal的有关问题,gdb调试都无反应了
一个signal的问题,gdb调试都无反应了C/C++ code#include stdio.h#include signal.h#include unistd.h
一个signal的问题,gdb调试都无反应了
C/C++ code#include <stdio.h>#include <signal.h>#include <unistd.h>#include <fcntl.h>void sig_handler(int signo){ char data[100]; int len ; len = read(STDIN_FILENO,&data,100); data[len]=0; printf("This signal is : %d\n",signo); printf("%s\n",data); exit(0);}int main(){ int oflags; signal(SIGINT,sig_handler); signal(SIGTERM,sig_handler); signal(SIGIO,sig_handler); fcntl(STDIN_FILENO,F_SETOWN,getpid()); printf("ID:%d\n",getpid()); oflags = fcntl(STDIN_FILENO,F_GETFL); fcntl(STDIN_FILENO,F_SETFL,oflags|FASYNC); while(1);}
Breakpoint 1 at 0x40125e: file sig.c, line 24.
(gdb) r
Starting program: /cygdrive/c/a/sig
[New Thread 9760.0x17cc]
[New Thread 9760.0x24a8]
ID:9760
Breakpoint 1, main () at sig.c:24
24 fcntl(STDIN_FILENO,F_SETFL,oflags|FASYNC);
(gdb) n
25 while(1);
(gdb) n
n
adflasjdflasfk
adflj
asdfkl
gggggh
无法退出来了。。。
[解决办法]没问题啊.
[liangdong@jx-csblog01.jx.baidu.com src]$ ./main
ID:27784
123
This signal is : 29
, len is : 4
123
你看到len是4了么, read是底层I/O, 只认识字节, 回车也是1字节, 所以len是4.