大神急救！！！！输入进程号pid，输出进程名pname。运行出现段错误，调试了很久，只想说这是有史以来遇到的最纠结的段错误，莫名其妙！
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>


void getProcessName(int pid, char *pname)
{
//get process name by shell
char cmd[100]={0};

sprintf(cmd,"readlink /proc/%d/exe >/pname.txt",pid);
system(cmd);

sleep(2);

//open file
int fd=open("/pname.txt" ,O_RDWR);
printf("#####%d\n",fd);
if(fd<0)
{
printf("open():\n");
return;
}
printf("!!!!!");

//read file
if(read(fd,pname,200)<0)
{
perror("read():\n");
return;
}


//close file
if(close(fd)<0)
{
perror("close():");
return;
}
//remove file
system("rm /pname.txt");
}

void main(){
int pid;
char chs[200];
printf("Please input pid: \n");
scanf("%d",pid);
getProcessName(pid, chs);
if(chs)
printf("The name of pid%d is %s: ", pid ,chs);
}

[解决办法]
要学会gdb啊 定位段错误几秒钟的事

scanf("%d",pid);