GNU/Linux man pages
Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :
GNU/Linux |
RedHat 5.2(Apollo) |
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fstat(2) |
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stat, fstat, lstat − get file status
#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);
These functions return information about the specified file. You do not need any access rights to the file to get this information but you need search rights to all directories named in the path leading to the file.
stat stats the file pointed to by file_name and fills in buf.
lstat is identical to stat, only the link itself is stated, not the file that is obtained by tracing the links.
fstat is identical to stat, only the open file pointed to by filedes (as returned by open(2)) is stated in place of file_name.
They all return a stat structure, which contains the following fields:
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 */
};
Note that st_blocks may not always be in terms of blocks of size st_blksize, and that st_blksize may instead provide a notion of the "preferred" blocksize for efficient file system I/O.
Not all of the Linux filesystems implement all of the time fields. Traditionally, st_atime is changed by mknod(2), utime(2), read(2), write(2), and truncate(2).
Traditionally, st_mtime is changed by mknod(2), utime(2), and write(2). The st_mtime is not changed for changes in owner, group, hard link count, or mode.
Traditionally, st_ctime is changed by writing or by setting inode information (i.e., owner, group, link count, mode, etc.).
The following POSIX macros are defined to check the file type:
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S_ISLNK(m) |
is it a symbolic link? |
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S_ISREG(m) |
regular file? |
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S_ISDIR(m) |
directory? |
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S_ISCHR(m) |
character device? |
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S_ISBLK(m) |
block device? |
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S_ISFIFO(m) |
fifo? |
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S_ISSOCK(m) |
socket? |
The following flags are defined for the st_mode field:
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S_IFMT |
00170000 bitmask for the file type bitfields (not POSIX) | ||
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S_IFSOCK |
0140000 socket (not POSIX) | ||
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S_IFLNK |
0120000 symbolic link (not POSIX) | ||
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S_IFREG |
0100000 regular file (not POSIX) | ||
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S_IFBLK |
0060000 block device (not POSIX) | ||
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S_IFDIR |
0040000 directory (not POSIX) | ||
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S_IFCHR |
0020000 character device (not POSIX) | ||
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S_IFIFO |
0010000 fifo (not POSIX) | ||
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S_ISUID |
0004000 set UID bit | ||
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S_ISGID |
0002000 set GID bit | ||
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S_ISVTX |
0001000 sticky bit (not POSIX) | ||
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S_IRWXU |
00700 user (file owner) has read, write and execute permission | ||
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S_IRUSR |
00400 user has read permission (same as S_IREAD, which is not POSIX) | ||
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S_IWUSR |
00200 user has write permission (same as S_IWRITE, which is not POSIX) | ||
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S_IXUSR |
00100 user has execute permission (same as S_IEXEC, which is not POSIX) | ||
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S_IRWXG |
00070 group has read, write and execute permission | ||
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S_IRGRP |
00040 group has read permission | ||
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S_IWGRP |
00020 group has write permission | ||
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S_IXGRP |
00010 group has execute permission | ||
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S_IRWXO |
00007 others have read, write and execute permission | ||
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S_IROTH |
00004 others have read permission | ||
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S_IWOTH |
00002 others have write permisson | ||
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S_IXOTH |
00001 others have execute permission |
On success, zero is returned. On error, −1 is returned, and errno is set appropriately.
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EBADF |
filedes is bad. |
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ENOENT |
File does not exist. |
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EFAULT |
Bad address. |
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EACCES |
Permission denied. |
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ENOMEM |
Out of memory (i.e. kernel memory). |
ENAMETOOLONG
File name too long.
The stat and fstat calls conform to SVr4, SVID, POSIX, X/OPEN, BSD 4.3. The lstat call conforms to 4.3BSD and SVr4. SVr4 documents additional fstat error conditions EFAULT, EINTR, ENOLINK, and EOVERFLOW. SVr4 documents additional stat and lstat error conditions EACCES, EFAULT, EINTR, ELOOP, EMULTIHOP, ENAMETOOLONG, ENOTDIR, ENOLINK, and EOVERFLOW.
chmod(2), chown(2), readlink(2), utime(2)
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fstat(2) | |