fstat(), fstat64() — Get status information about a file

Standards

Format

#define _POSIX_SOURCE
#include <sys/stat.h>

int fstat(int fildes, struct stat *info);

#define _LARGE_TIME_API
#define _POSIX_SOURCE
#include <sys/stat.h>

int fstat64 (int fildes, struct stat64 *info);

Compile requirement: Use of the fstat64() function requires the long long data type. For more information on how to make the long long data type available, see z/OS XL C/C++ Language Reference.

General description

Gets status information about the file specified by the open file descriptor fildes and stores it in the area of memory indicated by the info argument. The status information is returned in a stat or stat64 structure, as defined in the sys/stat.h header file. The elements of this structure are described in stat(), stat64() — Get file information.

The fstat64() function behaves exactly like fstat() except fstat64() uses structure stat64 instead of struct stat to support time beyond 03:14:07 UTC on January 19, 2038.

Large file support for z/OS UNIX files: fstat64() automatically supports large z/OS UNIX files for both AMODE 31 and AMODE 64 C/C++ applications, which means there is no need for _LARGE_FILES feature test macro to be defined. As for fstat(), the automatic support is only for AMODE 64 C/C++ applications. AMODE 31 C/C++ applications must be compiled with the option LANGLVL(LONGLONG) and define the _LARGE_FILES feature test macro before any headers are included to enable fstat() to operate on z/OS UNIX files that are larger than 2 GB in size. File size and offset fields are enlarged to 63 bits in width. Therefore, any other function operating on the file is required to define the _LARGE_FILES feature test macro as well.

Returned value

If successful, fstat() returns 0.

Example

/* CELEBF47 */
#define _POSIX_SOURCE
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#undef _POSIX_SOURCE
#include <stdio.h>
#include <time.h>

main() {
  char fn[]="temp.file";
  struct stat info;
  int fd;

  if ((fd = creat(fn, S_IWUSR)) < 0)
    perror("creat() error");
  else {
    if (fstat(fd, &info) != 0)
      perror("fstat() error");
    else {
      puts("fstat() returned:");
      printf("  inode:   %d\n",   (int) info.st_ino);
      printf(" dev id:   %d\n",   (int) info.st_dev);
      printf("   mode:   %08x\n",       info.st_mode);
      printf("  links:   %d\n",         info.st_nlink);
      printf("    uid:   %d\n",   (int) info.st_uid);
      printf("    gid:   %d\n",   (int) info.st_gid);
      printf("created:   %s",           ctime(&info.st_createtime));
    }
    close(fd);
    unlink(fn);
  }
}

Output

  inode:   3057
 dev id:   1
   mode:   03000080
  links:   1
    uid:   25
    gid:   500
created:   Fri Jun 16 16:03:16 2006

Related information

• sys/stat.h — z/OS UNIX files and access
• sys/types.h — typedef symbols and structures
• fcntl() — Control open file descriptors
• lstat(), lstat64() — Get status of file or symbolic link
• open() — Open a file
• stat(), stat64() — Get file information