ubuntu C++ 讀取文件夾下所有文件的文件名

#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>
#include <errno.h>
int main(int argc,char *argv[])
{

DIR *dp;
struct dirent *dirp;
int n=0;
if (argc!=2)
{
printf("a single argument is required\n");
return 0;
}
if((dp=opendir(argv[1]))==NULL)
printf("can't open %s",argv[1]);
while (((dirp=readdir(dp))!=NULL) && (n<=50))
{
n++;
printf("%s\n",dirp->d_name);
}
printf("\n");
closedir(dp);

return 0;
}