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STATX(2)                   Linux Programmer's ManualSTATX(2)NAME       statx - get file status (extended)SYNOPSIS       #include <sys/types.h>       #include <sys/stat.h>       #include <unistd.h>       #include <fcntl.h>           /* Definition of AT_* constants */       int statx(int dirfd, const char *pathname, int flags,                 unsigned int mask, struct statx *statxbuf);DESCRIPTION       This  function returns information about a file, storing it in the buf-       fer pointed to by statxbuf.  The returned buffer is a structure of  the       following type:           struct statx {               __u32 stx_mask;        /* Mask of bits indicating                                         filled fields */               __u32 stx_blksize;     /* Block size for filesystem I/O */               __u64 stx_attributes;  /* Extra file attribute indicators */               __u32 stx_nlink;       /* Number of hard links */               __u32 stx_uid;         /* User ID of owner */               __u32 stx_gid;         /* Group ID of owner */               __u16 stx_mode;        /* File type and mode */               __u64 stx_ino;         /* Inode number */               __u64 stx_size;        /* Total size in bytes */               __u64 stx_blocks;      /* Number of 512B blocks allocated */               __u64 stx_attributes_mask;                                      /* Mask to show what's supported                                         in stx_attributes */               /* The following fields are file timestamps */               struct statx_timestamp stx_atime;  /* Last access */               struct statx_timestamp stx_btime;  /* Creation */               struct statx_timestamp stx_ctime;  /* Last status change */               struct statx_timestamp stx_mtime;  /* Last modification */               /* If this file represents a device, then the next two                  fields contain the ID of the device */               __u32 stx_rdev_major;  /* Major ID */               __u32 stx_rdev_minor;  /* Minor ID */               /* The next two fields contain the ID of the device                  containing the filesystem where the file resides */               __u32 stx_dev_major;   /* Major ID */               __u32 stx_dev_minor;   /* Minor ID */           };       The file timestamps are structures of the following type:           struct statx_timestamp {               __s64 tv_sec;    /* Seconds since the Epoch (UNIX time) */               __u32 tv_nsec;   /* Nanoseconds since tv_sec */           };       (Note that reserved space and padding is omitted.)   Invoking statx():       To  access a file's status, no permissions are required on the file it-       self, but in the case of statx() with a pathname, execute (search) per-       mission  is required on all of the directories in pathname that lead to       the file.       statx() uses pathname, dirfd, and flags to identify the target file  in       one of the following ways:       An absolute pathname              If pathname begins with a slash, then it is an absolute pathname              that identifies the target file.  In this  case,  dirfd  is  ig-              nored.       A relative pathname              If  pathname is a string that begins with a character other than              a slash and dirfd is AT_FDCWD, then pathname is a relative path-              name that is interpreted relative to the process's current work-              ing directory.       A directory-relative pathname              If pathname is a string that begins with a character other  than              a  slash  and dirfd is a file descriptor that refers to a direc-              tory, then pathname is a relative pathname that  is  interpreted              relative to the directory referred to by dirfd.       By file descriptor              If  pathname  is  an  empty string and the AT_EMPTY_PATH flag is              specified in flags (see below), then the target file is the  one              referred to by the file descriptor dirfd.       flags  can  be  used to influence a pathname-based lookup.  A value for       flags is constructed by ORing together zero or more  of  the  following       constants:       AT_EMPTY_PATH              If  pathname is an empty string, operate on the file referred to              by dirfd (which may have been obtained using theopen(2)  O_PATH              flag).   In  this case, dirfd can refer to any type of file, not              just a directory.              If dirfd is AT_FDCWD, the call operates on the  current  working              directory.              This  flag  is  Linux-specific; define _GNU_SOURCE to obtain its              definition.       AT_NO_AUTOMOUNT              Don't automount the terminal ("basename") component of  pathname              if  it  is  a directory that is an automount point.  This allows              the caller to gather attributes of an  automount  point  (rather              than  the  location  it  would mount).  This flag can be used in              tools that scan directories to prevent  mass-automounting  of  a              directory  of automount points.  The AT_NO_AUTOMOUNT flag has no              effect if the mount point has already been mounted  over.   This              flag is Linux-specific; define _GNU_SOURCE to obtain its defini-              tion.       AT_SYMLINK_NOFOLLOW              If pathname is a symbolic link, do not dereference  it:  instead              return information about the link itself, likelstat(2).       flags can also be used to control what sort of synchronization the ker-       nel will do when querying a file on a remote filesystem.  This is  done       by ORing in one of the following values:       AT_STATX_SYNC_AS_STAT              Do  whateverstat(2) does.  This is the default and is very much              filesystem-specific.       AT_STATX_FORCE_SYNC              Force the attributes to be synchronized with the  server.   This              may  require  that a network filesystem perform a data writeback              to get the timestamps correct.       AT_STATX_DONT_SYNC              Don't synchronize anything, but rather just  take  whatever  the              system  has cached if possible.  This may mean that the informa-              tion returned is approximate, but, on a network  filesystem,  it              may not involve a round trip to the server - even if no lease is              held.       The mask argument to statx() is used to tell the  kernel  which  fields       the  caller  is interested in.  mask is an ORed combination of the fol-       lowing constants:           STATX_TYPE          Want stx_mode & S_IFMT           STATX_MODE          Want stx_mode & ~S_IFMT           STATX_NLINK         Want stx_nlink           STATX_UID           Want stx_uid           STATX_GID           Want stx_gid           STATX_ATIME         Want stx_atime           STATX_MTIME         Want stx_mtime           STATX_CTIME         Want stx_ctime           STATX_INO           Want stx_ino           STATX_SIZE          Want stx_size           STATX_BLOCKS        Want stx_blocks           STATX_BASIC_STATS   [All of the above]           STATX_BTIME         Want stx_btime           STATX_ALL           [All currently available fields]       Note that, in general, the kernel does not reject values in mask  other       than the above.  (For an exception, see EINVAL in errors.)  Instead, it       simply informs the caller which values are supported by this kernel and       filesystem  via the statx.stx_mask field.  Therefore, do not simply set       mask to UINT_MAX (all bits set), as one or more bits may,  in  the  fu-       ture, be used to specify an extension to the buffer.   The returned information       The  status  information  for  the target file is returned in the statx       structure pointed to by statxbuf.  Included in this is  stx_mask  which       indicates  what  other information has been returned.  stx_mask has the       same format as the mask argument and bits are set  in  it  to  indicate       which fields have been filled in.       It  should  be noted that the kernel may return fields that weren't re-       quested and may fail to return fields that were requested, depending on       what  the  backing  filesystem supports.  (Fields that are given values       despite being unrequested  can  just  be  ignored.)   In  either  case,       stx_mask will not be equal mask.       If  a  filesystem  does  not  support  a field or if it has an unrepre-       sentable value (for instance, a file with an  exotic  type),  then  the       mask  bit  corresponding to that field will be cleared in stx_mask even       if the user asked for it and a dummy value will be filled in  for  com-       patibility  purposes if one is available (e.g., a dummy UID and GID may       be specified to mount under some circumstances).       A filesystem may also fill in fields that the caller didn't ask for  if       it has values for them available and the information is available at no       extra cost.  If this happens, the corresponding bits  will  be  set  in       stx_mask.       Note:  for  performance and simplicity reasons, different fields in the       statx structure may contain state information  from  different  moments       during  the  execution of the system call.  For example, if stx_mode or       stx_uid is changed by another process by callingchmod(2) orchown(2),       stat()  might return the old stx_mode together with the new stx_uid, or       the old stx_uid together with the new stx_mode.       Apart from stx_mask (which is described above), the fields in the statx       structure are:       stx_blksize              The "preferred" block size for efficient filesystem I/O.  (Writ-              ing to a file in smaller chunks may cause an  inefficient  read-              modify-rewrite.)       stx_attributes              Further  status  information  about the file (see below for more              information).       stx_nlink              The number of hard links on a file.       stx_uid              This field contains the user ID of the owner of the file.       stx_gid              This field contains the ID of the group owner of the file.       stx_mode              The file type and mode.  Seeinode(7) for details.       stx_ino              The inode number of the file.       stx_size              The size of the file (if it is a  regular  file  or  a  symbolic              link)  in  bytes.   The size of a symbolic link is the length of              the pathname it contains, without a terminating null byte.       stx_blocks              The number of blocks allocated to the file  on  the  medium,  in              512-byte units.  (This may be smaller than stx_size/512 when the              file has holes.)       stx_attributes_mask              A mask indicating which bits in stx_attributes are supported  by              the VFS and the filesystem.       stx_atime              The file's last access timestamp.       stx_btime              The file's creation timestamp.       stx_ctime              The file's last status change timestamp.       stx_mtime              The file's last modification timestamp.       stx_dev_major and stx_dev_minor              The device on which this file (inode) resides.       stx_rdev_major and stx_rdev_minor              The  device  that this file (inode) represents if the file is of              block or character device type.       For further information on the above fields, seeinode(7).   File attributes       The stx_attributes field contains a set of ORed flags that indicate ad-       ditional  attributes  of the file.  Note that any attribute that is not       indicated as supported by stx_attributes_mask has no usable value here.       The  bits  in  stx_attributes_mask  correspond  bit-by-bit  to  stx_at-       tributes.       The flags are as follows:       STATX_ATTR_COMPRESSED              The file is compressed by the filesystem and may take extra  re-              sources to access.       STATX_ATTR_IMMUTABLE              The file cannot be modified: it cannot be deleted or renamed, no              hard links can be created to this file and no data can be  writ-              ten to it.  Seechattr(1).       STATX_ATTR_APPEND              The  file can only be opened in append mode for writing.  Random              access writing is not permitted.  Seechattr(1).       STATX_ATTR_NODUMP              File is not a candidate for backup when a backup program such asdump(8) is run.  Seechattr(1).       STATX_ATTR_ENCRYPTED              A  key  is required for the file to be encrypted by the filesys-              tem.RETURN VALUE       On success, zero is returned.  On error, -1 is returned, and  errno  is       set appropriately.ERRORS       EACCES Search  permission  is  denied for one of the directories in the              path prefix of pathname.  (See alsopath_resolution(7).)       EBADF  dirfd is not a valid open file descriptor.       EFAULT pathname or statxbuf is NULL or points to a location outside the              process's accessible address space.       EINVAL Invalid flag specified in flags.       EINVAL Reserved  flag specified in mask.  (Currently, there is one such              flag, designated by the constant STATX__RESERVED, with the value              0x80000000U.)       ELOOP  Too  many  symbolic links encountered while traversing the path-              name.       ENAMETOOLONG              pathname is too long.       ENOENT A component of pathname does not exist, or pathname is an  empty              string and AT_EMPTY_PATH was not specified in flags.       ENOMEM Out of memory (i.e., kernel memory).       ENOTDIR              A component of the path prefix of pathname is not a directory or              pathname is relative and dirfd is a file descriptor referring to              a file other than a directory.VERSIONS       statx() was added to Linux in kernel 4.11; library support was added in       glibc 2.28.CONFORMING TO       statx() is Linux-specific.SEE ALSOls(1),stat(1),access(2),chmod(2),chown(2),readlink(2),stat(2),utime(2),capabilities(7),inode(7),symlink(7)COLOPHON       This  page  is  part of release 5.05 of the Linux man-pages project.  A       description of the project, information about reporting bugs,  and  the       latest     version     of     this    page,    can    be    found    at       https://www.kernel.org/doc/man-pages/.Linux                             2019-10-10STATX(2)