/* We start with the appropriate headers and then a function, printdir,
which prints out the current directory.
It will recurse for subdirectories, using the depth parameter is used for indentation. */
#include <unistd.h>
#include <stdio.h>
#include <dirent.h>
#include <string.h>
#include <sys/stat.h>
#include <stdlib.h>
void printdir(char *dir, int depth)
{
// 目录流指针 对其可以采取 读 和 关闭的操作
DIR *dp;
// 文件结构的指针
struct dirent *entry;
// 状态结构
struct stat statbuf;
if((dp = opendir(dir)) == NULL) {
fprintf(stderr,"cannot open directory: %s\n", dir);
return;
}
// 切换到当前准备打印的目录
chdir(dir);
while((entry = readdir(dp)) != NULL) {
lstat(entry->d_name,&statbuf);
if(S_ISDIR(statbuf.st_mode)) {
/* Found a directory, but ignore . and .. */
// 跳过自身和父目录
if(strcmp(".",entry->d_name) == 0 ||
strcmp("..",entry->d_name) == 0)
continue;
printf("%*s%s/\n",depth,"",entry->d_name);
/* Recurse at a new indent level */
printdir(entry->d_name,depth+4);
}
else printf("%*s%s\n",depth,"",entry->d_name);
}
// 递归调用结束之后 返回父目录 因为给的相对路径 所以每次递归返回之后需要把当前工作目录切换回父目录
// 关闭开启的目录流
chdir("..");
closedir(dp);
}
/* Now we move onto the main function. */
int main(int argc, char* argv[])
{
// 默认是程序运行的当前目录 .
char *topdir, pwd[2]=".";
if (argc != 2)
topdir=pwd;
else
topdir=argv[1];
printf("Directory scan of %s\n",topdir);
printdir(topdir,0);
printf("done.\n");
exit(0);
}
参考资料： 《Linux程序设计4th》
