#include"user.h"#include"types.h"#include"fs.h"#include"fcntl.h"char*args[100];intmain(void){charbuf[128];intpid;while(1){puts("$ ");gets(buf,sizeof(buf));if(buf[0]=='\0')continue;pid=fork();if(pid==0){args[0]=buf;args[1]=0;exec(buf,args);printf(1,"%s: not found\n",buf);exit();}if(pid>0)wait();}}