进程串
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
int main(){int p1,p2,p3,p4;while((p1=fork())==-1);if(p1==0){printf("child %d parent %d\n",getpid(),getppid());while((p2=fork())==-1);if(p2==0){// child process printf("child %d parent %d\n",getpid(),getppid());while((p3=fork())==-1);if(p3==0){printf("child %d parent %d\n",getpid(),getppid());while((p4=fork())==-1);}}}//printf("child %d parent %d\n",getpid(),gitppid());return 0;
}~
~ 进程树
#include <stdio.h>
#include <unistd.h>int main(){int p1,p2,p3,p4,p5,p6;while((p4=fork())<0);while((p1=fork())<0);if(p1==0){printf("child %d parent %d\n",getpid(),getppid());while((p2=fork())<0);if(p2==0){printf("child %d parent %d\n",getpid(),getppid());while((p3=fork())<0);if(p3==0){printf("child %d parent %d\n",getpid(),getppid());}}}
// 如果不是else 则发现会子进程执行else if(p4==0){printf("child %d parent %d\n",getpid(),getppid());while((p5=fork())<0);if(p5==0){printf("child %d parent %d\n",getpid(),getppid());}while((p6=fork())<0);if(p5==0){printf("child %d parent %d\n",getpid(),getppid());}}return 0;
}