linux对文件夹以及文件名的长度做了限制，以ubuntu为例，描述文件路径为：/usr/include/linux/limits.h

#ifndef _LINUX_LIMITS_H

#define _LINUX_LIMITS_H

#define NR_OPEN 1024

#define NGROUPS_MAX 65536 /* supplemental group IDs are available */

#define ARG_MAX 131072 /* # bytes of args + environ for exec() */

#define LINK_MAX 127 /* # links a file may have */

#define MAX_CANON 255 /* size of the canonical input queue */

#define MAX_INPUT 255 /* size of the type-ahead buffer */

#define NAME_MAX 255 /* # chars in a file name */

#define PATH_MAX 4096 /* # chars in a path name including nul */

#define PIPE_BUF 4096 /* # bytes in atomic write to a pipe */

#define XATTR_NAME_MAX 255 /* # chars in an extended attribute name */

#define XATTR_SIZE_MAX 65536 /* size of an extended attribute value (64k) */

#define XATTR_LIST_MAX 65536 /* size of extended attribute namelist (64k) */

#define RTSIG_MAX 32

#endif

android对文件名和路径也有类似的限制，据说文件名太长，可能会造成扫描直接崩溃。