我最近问了一个关于如何在c程序中调用hping3的问题。 提供的解决方案有效,但我现在有另一个问题。必须将hping3的输出传递给父进程,因此我执行了以下操作。 请注意,这只是代码片段,我认为错误在其中。 以下片段在循环内部运行,其中我遍历一系列ip地址,这对于在我的mpi程序中提供两种不同的分发策略是必要的。
//Stick together the params
sprintf(params, "--scan %u %u.%u.%u.%u -V", *(portarray + i), (iterator & 0xFF000000)>>24, (iterator & 0x00FF0000)>>16, (iterator & 0x0000FF00)>>8, (iterator & 0x000000FF));
//Pipe and check status
if(pipe(pipes)==-1){
perror("Error piping");
}
//Fork and check status
pid=fork();
if(pid == -1){
perror("Error forking");
} else if(pid > 0){
//Parent does not write
close(pipes[1]);
//Save stdout from pipe
nbytes = read(pipes[0], buffer, sizeof(buffer));
//Parent, wait for child
waitpid(pid, &status, 0);
//Print out pipe
printf("hping3: (%.*s)\n", nbytes, buffer);
wait(NULL);
close(pipes[0]);
} else {
//Child does not read
close(pipes[0]);
//Map stdout and stderr to write pipe-end
dup2(pipes[1], 1);
dup2(pipes[1], 2);
//Child, exec hping with params
execl("sudo /usr/sbin/hping3","sudo /usr/sbin/hping3",params,NULL);
close(pipes[1]);
//Exit child to prevent fork-bomb
return 0;
}
//Sleep for specified delaytime
sleep((unsigned int)delay);
我无法找出问题所在。 输出如下(当然是循环中):
hping3()
hping3程序打印到stdout和stderr,我通过输出重定向到文件在shell上测试它。
答案 0 :(得分:1)
如何定义缓冲区?你有没有检查过nbytes的值?你确定正在执行hping吗?我尝试使用以下内容:
int buffsize = 100;
char * buffer = malloc(buffsize);
if (pid == -1) {
perror("Error forking");
} else if (pid > 0) {
//Parent does not write
close(pipes[1]);
// I'd first wait for the child to finish.
waitpid(pid, &status, 0);
// Save stdout from pipe
// recall that sizeof(buffer) != buffsize when malloc'ed.
int count = 0;
while((nbytes = read(pipes[0], buffer+count, buffsize-count) != -1) count += nbytes;
//Print out pipe
printf("hping3: (%.*s)\n", nbytes, buffer);
wait(NULL);
close(pipes[0]);
} else {
//Child does not read
close(pipes[0]);
//Map stdout and stderr to write pipe-end
dup2(pipes[1],1);
dup2(pipes[1],2);
// Close pipes[1]
close(pipes[1]);
//Child, exec hping with params
if (execl("sudo /usr/sbin/hping3","sudo /usr/sbin/hping3",params,NULL) == -1)
perror("execl error");
//Exit child to prevent fork-bomb
return 0;
}