unix 环境高级编成 程序清单1-1 列出一个目录中所有的文件

$ cat fig1.3.c
#include "include/apue.h"
#include <dirent.h>

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

if (argc != 2)
err_quit("usage: ls directory_name");

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);
}

$ ./a.out ./
.
..
Makefile
Make.defines.freebsd
Make.defines.linux
Make.defines.macos