Linux Certif

Toute la documentation sur la certification Linux LPI

Rechercher une page de manuel

lstat

À̸§

stat, fstat, lstat - ÆÄÀÏ »óŸ¦ ¾ò´Â´Ù

»ç¿ë¹ý

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

int stat(const char *file_name, struct stat *buf);
int fstat(int filedes, struct stat *buf);
int lstat(const char *file_name, struct stat *buf);

¼³¸í

ÀÌ ÇÔ¼ö´Â ÁöÁ¤µÈ ÆÄÀÏ¿¡ ´ëÇÑ Á¤º¸¸¦ ¹ÝȯÇÑ´Ù. ÀÌ Á¤º¸¸¦ ¾ò±â À§ÇØ ÇÊ¿äÇÑ Á¢±Ù ±ÇÇÑÀº ¾øÁö¸¸, ÆÄÀÏÀ» Àд °æ·Î¿¡ ÀÖ´Â ¸ðµç µð·ºÅ丮¿¡ ´ëÇÑ Å½»ö ±ÇÇÑÀÌ ÇÊ¿äÇÏ´Ù.

stat ´Â file_name À¸·Î ÁöÁ¤µÈ ÆÄÀÏ¿¡ ´ëÇØ ¼³¸íÇÏ°í buf ¿¡ ä¿î´Ù. lstat ´Â stat ¿Í µ¿ÀϽõȴÙ.¸µÅ©´Â ±× ÀÚü·Î ¼³¸íµÈ´Ù, ¸µÅ©¿¡ Æ÷ÇԵǾî ÀÖ´Â ÆÄÀÏÀ» ¼³¸íÇÏÁö ¾Ê´Â´Ù. fstat ´Â stat¿Í µ¿ÀϽõȴÙ. file_name. ´ë½Å¿¡ filedes ¿¡ ÀÇÇØ ÁöÁ¤µÈ ¿­¸° ÆÄÀϸ¸ ( open(2) ¿¡ ÀÇÇØ ¹ÝȯµÇµíÀÌ) ¼³¸íµÈ´Ù.

±×°ÍµéÀº ¸ðµÎ ¾Æ·¡ ¿µ¿ªÀ» Æ÷ÇÔÇÏ´Â stat ±¸Á¶À» ¹ÝȯÇÑ´Ù:

 struct stat
 {
     dev_t         st_dev;      /* device */
     ino_t         st_ino;      /* inode */
     mode_t        st_mode;     /* protection */
     nlink_t       st_nlink;    /* number of hard links */
     uid_t         st_uid;      /* user ID of owner */
     gid_t         st_gid;      /* group ID of owner */
     dev_t         st_rdev;     /* device type (if inode device) */
     off_t         st_size;     /* total size, in bytes */
     unsigned long st_blksize;  /* blocksize for filesystem I/O */
     unsigned long st_blocks;   /* number of blocks allocated */
     time_t        st_atime;    /* time of last access */
     time_t        st_mtime;    /* time of last modification */
     time_t        st_ctime;    /* time of last change */
 };
 

The value st_blocks °ªÀº 512-bytes ºí·Ï¿¡ ÀÖ´Â ÆÄÀÏÀÇ Å©±â¸¦ ÁØ´Ù. st_blksize °ªÀº È¿À²ÀûÀÎ ÆÄÀÏ ½Ã½ºÅÛ I/O¸¦ À§ÇØ "¼±ÅõÈ" ºí·Ï Å©±â¸¦ ÁØ´Ù. (´õ ÀÛÀº °ø°£¿¡ ÆÄÀÏÀ» ¾²´Â °ÍÀº ¾²°í-¼öÁ¤ÇÏ°í-´Ù½Ã ¾²´Âµ¥ ºñÈ¿À²ÀûÀÌ´Ù.)4

¸ðµç ¸®´ª½º ÆÄÀϽýºÅÛÀÌ ¸ðµç ½Ã°£ ¿µ¿ª¿¡¼­ ½ÇÇàÇÏ´Â °ÍÀº ¾Æ´Ï´Ù. ÀüÅëÀûÀ¸·Î, st_atime ´Â mknod(2), utime(2), read(2), write(2),¿Í truncate(2). ·Î ¹Ù²î¾ú´Ù. ÀüÅëÀûÀ¸·Î, st_mtime ´Â mknod(2), utime(2),¿Í write(2). ·Î ¹Ù²î¾ú´Ù. st_mtime ´Â ¼ÒÀ¯ÀÚ, ±×·ì, Çϵ帵ũ Ä«¿îÆ®, ȤÀº ¸ðµåÀÇ º¯È­¿¡ µû¶ó ¹Ù²îÁö ¾Ê¾Ò´Ù. ÀüÅëÀûÀ¸·Î, st_ctime ´Â inode Á¤º¸¸¦ ¾²°Å³ª ¼³Á¤ÇÔÀ¸·Î½á ¹Ù²î¾ú´Ù.(i.e., owner, group,link count, mode,µîµî).

¾Æ·¡ POSIX ¸ÅÅ©·Î´Â ÆÄÀÏ Å¸ÀÔÀ» È®ÀÎÇÏ´Â °ÍÀÌ´Ù:

S_ISLNK(m)

is it a symbolic link?

S_ISREG(m)

regular file?

S_ISDIR(m)

directory?

S_ISCHR(m)

character device?

S_ISBLK(m)

block device?

S_ISFIFO(m)

fifo?

S_ISSOCK(m)

socket?

¾Æ·¡ flag´Â st_mode ¿µ¿ªÀ» À§ÇØ Á¤ÀÇµÈ °ÍÀÌ´Ù:

S_IFMT	0170000	bitmask for the file type bitfields
S_IFSOCK	0140000	socket
S_IFLNK	0120000	symbolic link
S_IFREG	0100000	regular file
S_IFBLK	0060000	block device
S_IFDIR	0040000	directory
S_IFCHR	0020000	character device
S_IFIFO	0010000	fifo
S_ISUID	0004000	set UID bit
S_ISGID	0002000	set GID bit (see below)
S_ISVTX	0001000	sticky bit (see below)
S_IRWXU	00700	mask for file owner permissions
S_IRUSR	00400	owner has read permission
S_IWUSR	00200	owner has write permission
S_IXUSR	00100	owner has execute permission
S_IRWXG	00070	mask for group permissions
S_IRGRP	00040	group has read permission
S_IWGRP	00020	group has write permission
S_IXGRP	00010	group has execute permission
S_IRWXO	00007	mask for permissions for others (not in group)
S_IROTH	00004	others have read permission
S_IWOTH	00002	others have write permisson
S_IXOTH	00001	others have execute permission

GID ºñÆ® (S_ISGID)¼³Á¤Àº ¸î°¡Áö Ưº°ÇÑ ÀÌ¿ë¹ýÀÌ ÀÖ´Ù: µð·ºÅ丮ÀÇ °æ¿ì BSD semanticÀÌ ¾²ÀÌ°í ÀÖÀ½ÀÌ ³ªÅ¸³­´Ù: »ý¼ºµÈ ÆÄÀÏÀº »ý¼º ÇÁ·Î¼¼½º¿Í »ý¼ºµÈ µð·ºÅ丮ÀÇ À¯È¿ÇÑ gid·ÎºÎÅÍ°¡ ¾Æ´Ï¶ó µð·ºÅ丮·ÎºÎÅÍ ±×µéÀÇ ±×·ì ID¸¦ »ó¼Ó¹Þ´Â´Ù. ±×¸®°í S_ISGID ºñÆ®±ºÀ» °¡Áø´Ù. ½ÇÇà ºñÆ®(S_IXGRP)±ºÀ» °®Áö ¾ÊÀº ÆÄÀÏÀÇ °æ¿ì, mandatory file/record lockingÀ» ³ªÅ¸³½´Ù. µð·ºÅ丮 »óÀÇ `sticky' bit (S_ISVTX)´Â µð·ºÅ丮¾ÈÀÇ ÆÄÀÏÀÌ ÆÄÀÏÀÇ ¼ÒÀ¯ÀÚ, µð·ºÅ丮ÀÇ ¼ÒÀ¯ÀÚ, ±×¸®°í ·çÆ®¿¡ ÀÇÇØ À̸§À» ¹Ù²î°Å³ª Áö¿öÁú ¼ö ÀÖ´Ù´Â °ÍÀ» ¶æÇÑ´Ù.

¹Ýȯ°ª

¼º°ø½Ã, 0ÀÌ ¹ÝȯµÇ°í, ½ÇÆнÃ, -1ÀÌ ¹ÝȯµÈ´Ù. ±×¸®°í errno ´Â ÀûÀýÇÑ °ªÀ¸·Î ¼³Á¤µÈ´Ù.

¿¡·¯

EBADF

filedes ´Â À߸øµÆ´Ù.

ENOENT

A component of the path file_name °æ·ÎÀÇ ±¸¼º¿ä¼Ò°¡ Á¸ÀçÇÏÁö ¾Ê°Å³ª °æ·Î°¡ ºó ¹®ÀÚ¿­ÀÌ´Ù.

ENOTDIR

°æ·ÎÀÇ ±¸¼º¿ä¼Ò°¡ µð·ºÅ丮°¡ ¾Æ´Ï´Ù.

ELOOP

½Éº¼¸¯¸µÅ©°¡ ³Ê¹« ¸¹´Ù.

EFAULT

À߸øµÈ ÁÖ¼ÒÀÌ´Ù.

EACCES

±ÇÇÑÀÌ °ÅºÎµÆ´Ù.

ENOMEM

¸Þ¸ð¸® ºÎÁ·.

ENAMETOOLONG

ÆÄÀϸíÀÌ ³Ê¹« ±æ´Ù.

ȣȯ

stat ¿Í fstat È£ÃâÀº SVr4, SVID, POSIX, X/OPEN, BSD 4.3¿¡ µû¸¥´Ù. lstat È£ÃâÀº 4.3BSD and SVr4¿¡ µû¸¥´Ù. SVr4´Â Ãß°¡ÀûÀ¸·Î documents additional fstat ¿¡·¯ »óÅÂÀÎ EINTR, ENOLINK, EOVERFLOW¸¦ ¹®¼­È­Çß´Ù. SVr4 ´Â Ãß°¡ÀûÀ¸·Î stat ¿Í lstat ÀÇ ¿¡·¯ÀÎ EACCES, EINTR, EMULTIHOP, ENOLINK, EOVERFLOW¸¦ ¹®¼­È­Çß´Ù. st_blocks ¿Í st_blksize ÇʵåÀÇ »ç¿ëÀº ÀÌ½ÄµÉ ¼ö ¾ø´Ù. (±×°ÍµéÀº POSIX¿¡ÀÇÇØ ÁöÁ¤µÈ°ÍÀÌ ¾Æ´Ï°í BSD¿¡¼­ ¼Ò°³µÇ¾ú´Ù. Çؼ®Àº ½Ã½ºÅÛ¸¶´Ù ´Ù¸£°í, ½Ì±Û ½Ã½ºÅÛ¿¡¼­ NFS°¡ ¸¶¿îÆ®µÇ¸é º¹ÀâÇØÁø´Ù.)

POSIXÀº S_IFMT, S_IFSOCK, S_IFLNK, S_IFREG, S_IFBLK, S_IFDIR, S_IFCHR, S_IFIFO, S_ISVTX ºñÆ®¿¡ ´ëÇØ ¼³¸íÇÏÁö ¾ÊÁö¸¸, ´ë½Å S_ISDIR()µîÀÇ ¸ÅÅ©·Î »ç¿ëÀº ¿ä±¸ÇÑ´Ù. À¯´Ð½º V7 (À̳ª ÈÄÀÇ ½Ã½ºÅÛ)Àº POSIX¿¡¼­ ±ÔÁ¤ÇÑ À¯»ç¾îÀÎ S_IRUSR, S_IWUSR, S_IXUSR ÀÇ S_IREAD, S_IWRITE, S_IEXEC¸¦ °®´Â´Ù.

Ÿ ½Ã½ºÅÛ

´Ù¾çÇÑ ½Ã½ºÅÛ¿¡¼­ »ç¿ëµÇ´Â °ªµé:

hex	À̸§	ls	octal	¼³¸í
f000	S_IFMT		170000	ÆÄÀÏŸÀÔÀ» À§ÇÑ mask
0000			000000	SCO out-of-service inode, BSD unknown type
				SVID-v2 and XPG2 have both 0 and 0100000 for ordinary file
1000	S_IFIFO	p|	010000	fifo (named pipe)
2000	S_IFCHR	c	020000	character special (V7)
3000	S_IFMPC		030000	multiplexed character special (V7)
4000	S_IFDIR	d/	040000	directory (V7)
5000	S_IFNAM		050000	XENIX named special file
				with two subtypes, distinguished by st_rdev values 1, 2:
0001	S_INSEM	s	000001	XENIX semaphore subtype of IFNAM
0002	S_INSHD	m	000002	XENIX shared data subtype of IFNAM
6000	S_IFBLK	b	060000	block special (V7)
7000	S_IFMPB		070000	multiplexed block special (V7)
8000	S_IFREG	-	100000	regular (V7)
9000	S_IFCMP		110000	VxFS compressed
9000	S_IFNWK	n	110000	network special (HP-UX)
a000	S_IFLNK	l@	120000	symbolic link (BSD)
b000	S_IFSHAD		130000	Solaris shadow inode for ACL (not seen by userspace)
c000	S_IFSOCK	s=	140000	socket (BSD; also "S_IFSOC" on VxFS)
d000	S_IFDOOR	D	150000	Solaris door
e000	S_IFWHT	w%	160000	BSD whiteout (not used for inode)
0200	S_ISVTX		001000	`sticky bit': save swapped text even after use (V7)
				reserved (SVID-v2)
				On non-directories: don't cache this file (SunOS)
				On directories: restricted deletion flag (SVID-v4.2)
0400	S_ISGID		002000	set group ID on execution (V7)
				for directories: use BSD semantics for propagation of gid
0400	S_ENFMT		002000	SysV file locking enforcement (shared w/ S_ISGID)
0800	S_ISUID		004000	set user ID on execution (V7)
0800	S_CDF		004000	directory is a context dependent file (HP-UX)

sticky ¸í·ÉÀº AT&T UNIX V32¿¡¼­ ¼±º¸¿´´Ù.

°ü·Ã Ç׸ñ

chmod(2), chown(2), readlink(2), utime(2)