linux下哪个系统调用函数可以得到指定目录下的所有文件？

opendir/readdir/closedir: 读取目录资讯
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#include
DIR * opendir(const char * pathname);
int closedir(DIR *dir);
struct dirent * readdir(DIR *dir);
int rewinddir(DIR *dir);
struct dirent {
long d_ino; /* inode number */
off_t d_off; /* offset to this dirent */
unsigned short d_reclen; /* length of this d_name */
char d_name [NAME_MAX+1]; /* file name (null-terminated) */
};
opendir开启一个目录操作DIR，closedir关闭之。
readdir则循序读取目录中的资讯。

以下是个标准例。
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#include
#include
char ** dirGetInfo(const char *pathname)
{
char ** filenames;
DIR * dir;
struct dirent * ent;
int n = 0;
filenames = (char **)malloc(sizeof(char*));
filenames[0]=NULL;

dir = opendir(pathname);
if (!dir) return filenames;
while ((ent = readdir(dir))) {
filenames = (char**)realloc(filenames,sizeof(char*)*(n+1));
filenames[n] = strdup(ent->d_name);
n++;
}

closedir(dir);
filenames = (char **)realloc(filenames,sizeof(char*)*(n+1));
filenames[n] = NULL;
return filenames;
}

readdir函数，相关的数据结构请参考：
http://baike.baidu.com/view/4380003.htm