文件名长度定义

Linux下定义了文件名长度及路径名长度限制，具体在文件/usr/include/linux/limits.h中：

#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

可以看到路径名长度为4096个字符(包括nul结尾)，而文件名长度为255个字符。