stat

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  control  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 con-
       tinue 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

       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 argument, 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 structure.


       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 directory. 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;
                      continue;


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


                  /* Print out owner'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 vol-



IEEE/The Open Group                  2003                              STAT(P)