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STAT(P)                                                                STAT(P)



NAME
       stat - get file status

SYNOPSIS
       #include <sys/stat.h>

       int stat(const char *restrict path, struct stat *restrict buf);


DESCRIPTION
       The  stat()  function shall obtain information about the named file and write it to
       the area pointed to by the buf argument. The path argument  points  to  a  pathname
       naming  a  file.   Read,  write,  or  execute  permission  of the named file is not
       required. An implementation that provides additional or alternate file access  con-
       trol mechanisms may, under implementation-defined conditions, cause stat() to fail.
       In particular, the system may deny the existence of the file specified by path.

       If the named file is a symbolic link, the stat() function shall  continue  pathname
       resolution  using  the  contents of the symbolic link, and shall return information
       pertaining to the resulting file if the file exists.

       The buf argument is a pointer to a stat structure, as defined in  the  <sys/stat.h>
       header, into which information is placed concerning the file.

       The  stat() function shall update any time-related fields (as described in the Base
       Definitions volume of IEEE Std 1003.1-2001, Section 4.7, File Times Update), before
       writing into the stat structure.

       Unless  otherwise specified, the structure members st_mode, st_ino, st_dev, st_uid,
       st_gid, st_atime, st_ctime, and st_mtime shall have meaningful values for all  file
       types  defined  in  this  volume  of  IEEE Std 1003.1-2001. The value of the member
       st_nlink shall be set to the number of links to the file.

RETURN VALUE
       Upon successful completion, 0 shall be returned. Otherwise, -1  shall  be  returned
       and errno set to indicate the error.

ERRORS
       The stat() function shall fail if:

       EACCES Search permission is denied for a component of the path prefix.

       EIO    An error occurred while reading from the file system.

       ELOOP  A  loop  exists  in symbolic links encountered during resolution of the path
              argument.

       ENAMETOOLONG
              The length of the path argument exceeds {PATH_MAX} or a  pathname  component
              is longer than {NAME_MAX}.

       ENOENT A  component  of  path  does  not  name an existing file or path is an empty
              string.

       ENOTDIR
              A component of the path prefix is not a directory.

       EOVERFLOW
              The file size in bytes or the number of blocks allocated to the file or  the
              file  serial number cannot be represented correctly in the structure pointed
              to by buf.


       The stat() function may fail if:

       ELOOP  More than {SYMLOOP_MAX} symbolic links were encountered during resolution of
              the path argument.

       ENAMETOOLONG
              As  a result of encountering a symbolic link in resolution of the path argu-
              ment, the length of the substituted pathname string exceeded {PATH_MAX}.

       EOVERFLOW
              A value to be stored would overflow one of the members of  the  stat  struc-
              ture.


       The following sections are informative.

EXAMPLES
   Obtaining File Status Information
       The  following example shows how to obtain file status information for a file named
       /home/cnd/mod1. The structure variable buffer is defined for the stat structure.


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


              struct stat buffer;
              int         status;
              ...
              status = stat("/home/cnd/mod1", &buffer);

   Getting Directory Information
       The following example fragment gets status information for each entry in  a  direc-
       tory. The call to the stat() function stores file information in the stat structure
       pointed to by statbuf. The lines that follow the stat() call format the  fields  in
       the stat structure for presentation to the user of the program.


              #include <sys/types.h>
              #include <sys/stat.h>
              #include <dirent.h>
              #include <pwd.h>
              #include <grp.h>
              #include <time.h>
              #include <locale.h>
              #include <langinfo.h>
              #include <stdio.h>
              #include <stdint.h>


              struct dirent  *dp;
              struct stat     statbuf;
              struct passwd  *pwd;
              struct group   *grp;
              struct tm      *tm;
              char            datestring[256];
              ...
              /* Loop through directory entries. */
              while ((dp = readdir(dir)) != NULL) {


                  /* Get entryâ€â€™s information. */
                  if (stat(dp->d_name, &statbuf) == -1)
                      continue;


                  /* Print out type, permissions, and number of links. */
                  printf("%10.10s", sperm (statbuf.st_mode));
                  printf("%4d", statbuf.st_nlink);


                  /* Print out ownerâ€â€™s name if it is found using getpwuid(). */
                  if ((pwd = getpwuid(statbuf.st_uid)) != NULL)
                      printf(" %-8.8s", pwd->pw_name);
                  else
                      printf(" %-8d", statbuf.st_uid);


                  /* Print out group name if it is found using getgrgid(). */
                  if ((grp = getgrgid(statbuf.st_gid)) != NULL)
                      printf(" %-8.8s", grp->gr_name);
                  else
                      printf(" %-8d", statbuf.st_gid);


                  /* Print size of file. */
                  printf(" %9jd", (intmax_t)statbuf.st_size);


                  tm = localtime(&statbuf.st_mtime);


                  /* Get localized date string. */
                  strftime(datestring, sizeof(datestring), nl_langinfo(D_T_FMT), tm);


                  printf(" %s %s\n", datestring, dp->d_name);
              }

APPLICATION USAGE
       None.

RATIONALE
       The intent of the paragraph describing "additional or alternate file access control
       mechanisms" is to allow a secure implementation where a process with a  label  that
       does  not  dominate  the file’s label cannot perform a stat() function. This is not
       related to read permission; a process with a label that dominates the file’s  label
       does  not need read permission. An implementation that supports write-up operations
       could fail fstat() function calls even though it has a valid file  descriptor  open
       for writing.

FUTURE DIRECTIONS
       None.

SEE ALSO
       fstat()  ,  lstat()  ,  readlink()  ,  symlink()  ,  the Base Definitions volume of
       IEEE Std 1003.1-2001, <sys/stat.h>, <sys/types.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std
       1003.1,  2003  Edition,  Standard  for Information Technology -- Portable Operating
       System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C)
       2001-2003  by  the  Institute  of Electrical and Electronics Engineers, Inc and The
       Open Group. In the event of any discrepancy between this version and  the  original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is
       the  referee  document.  The  original  Standard  can   be   obtained   online   at
       http://www.opengroup.org/unix/online.html .



POSIX                                2003                              STAT(P)

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