ls的源代码

下面是一个简单的ls，copy自《UNIX环境高级编程》
#include
#include
#include"ourhdr.h"

int
main(int argc, char *argv[])
{
DIR*dp;
struct dirent*dirp;

if (argc != 2)
err_quit("a single argument (the directory name) is required");

if ( (dp = opendir(argv[1])) == NULL)
err_sys("can't open %s", argv[1]);

while ( (dirp = readdir(dp)) != NULL)
printf("%s\n", dirp->d_name);

closedir(dp);
exit(0);
}