w_statfs

w_statfs

Get File System Status Information

Portability: SAS/C extension

SYNOPSIS
DESCRIPTION
RETURN VALUE
PORTABILITY
EXAMPLE
RELATED FUNCTIONS

SYNOPSIS

#include <sys/statfs.h>

int w_statfs(const char *fileSystem, struct w_statfs *statInfo,
             size_t infoSize);

DESCRIPTION

w_statfs gets file system status information. The following arguments are required:

fileSystem

is the name of the file system for which status information is to be provided. File system names can be obtained by using the w_getmntent function.

statInfo

is a pointer to a w_statfs structure that is declared in the <sys/statfs.h> header. The following elements of this structure provide file system status information:

int statfs_len: is the size of the w_statfs structure.
int statfs_blksize: is the block size for the file system.
unsigned int statfs_total_space: is the total number of blocks used by the file system.
unsigned int statfs_free_space: is the number of free blocks available to unprivileged users.

infoSize

specifies the number of bytes of information to be stored. If infoSize is larger than the size of the w_statfs structure, then all of the information is stored; if it is shorter than the structure, then only a portion of the information is stored; and if infoSize is 0 , then no information is stored. A value of 0 for infoSize may be used to test whether or not a file system exists.

RETURN VALUE

If successful, w_statfs returns the number of bytes stored. If infoSize is 0 , the total number of bytes of information available is returned. A -1 is returned if unsuccessful.

PORTABILITY

The w_statfs function may be useful in USS applications; however, it is not defined by the POSIX.1 standard and should not be used in portable applications.

EXAMPLE

The following example illustrates the use of w_statfs to obtain file system status information:

#include <sys/types.h>
#include <sys/statfs.h>
#include <sys/stat.h>
#include <string.h>
#include <stdio.h>
  
main()
{
   const char fileSys[] = "POSIX.FILE.SYSTEM";
   char *mountPoint = "/u/userid/dev";
   char *mountType = "HFS     ";
   struct w_statfs workArea;

      /* Initialize work area.               */
   memset(&workArea, 0x00, sizeof(workArea));

      /* Mount file system.                  */
   if (mount(mountPoint, fileSys, mountType, MTM_RDWR, 0, NULL) != 0)
      perror("error mounting file system");

      /* Get file system status information. */
   if (w_statfs(fileSys, &workArea, sizeof(workArea)) == -1)
      perror("w_statfs error");
   else
      printf("Length = %dn", workArea.statfs_len);
      printf("Block Size = %dn", workArea.statfs_blksize);
      printf("Blocks Used = %un", workArea.statfs_total_space);
      printf("Blocks Allocated = %un", workArea.statfs_used_space);
      printf("Free Space = %un", workArea.statfs_free_space);
}

RELATED FUNCTIONS

w_statfs , w_getmntent

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