用C给出父PID时如何得到所有子进程的PID [英] How to get all child process's PIDs when given the parent PID in C

问题描述

我知道，这可以在bash这样做： pstree父-PID 。但我怎么能做到这一点用C ？有没有不必遍历整个/ proc文件系统中的任何方法（例如系统调用/库函数）？

I know that this can be done in bash by: pstree parent-pid. But how can I do this in C? Is there any method that doesn't have to iterating the whole /proc file system (e.g. system call/library function)?

推荐答案

您可以使用的popen 读命令 PS -ef的输出，然后查找所有的子进程指定 PID

you can use popen to read the output of the command ps -ef,then look for the all the child process of a specified PID

int getAllChildProcess(pid_t ppid)
{
   char *buff = NULL;
   size_t len = 255;
   char command[256] = {0};

   sprintf(command,"ps -ef|awk '$3==%u {print $2}'",ppid);
   FILE *fp = (FILE*)popen(command,"r");
   while(getline(&buff,&len,fp) >= 0)
   {
     printf("%s\n",buff);
   }
   free(buff);
   fclose(fp);
   return 0;
}

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