sysfs(2)

NAME

sysfs — get file system type information

SYNOPSIS

#include <sys/fstyp.h> 

int sysfs(int opcode, const char *fsname); 

int sysfs(int opcode, int fs_index, char *buf ); 

int sysfs(int opcode);

DESCRIPTION

sysfs is used to return information about the file system types configured in the system. The number arguments accepted by sysfs varies and depends on the opcode.

The current recognized opcodes and their functions are:

GETFSIND: Translate fsname, a null-terminated file-system type identifier, into a file-system type index.
GETFSTYP: Translate fs_index, a file-system type index, into a null-terminated file-system type identifier and write it into the buffer pointed to by buf; this buffer must be at least of size FSTYPSZ as defined in <sys/fstyp.h>. If there is no file-system type configured at fs_index, a null string is returned for the file-system type identifier.
GETNFSTYP: Return one more than the largest file system type configured. This is not the number of file system types configured, because the type numbers may not be contiguous. See the example below.

RETURN VALUE

Upon successful completion, sysfs() returns the file-system type index if the opcode is GETFSIND, a value of 0 if the opcode is GETFSTYP, or the number of file system types configured if the opcode is GETNFSTYP. Otherwise, a value of -1 is returned and errno is set to indicate the error.

ERRORS

sysfs fails if one or more of the following are true and sets errno to the value indicated:

EINVAL: fsname points to an invalid file-system identifier; fs_index is negative or greater than the largest file-system type index; opcode is invalid.
EFAULT: buf or fsname points to an invalid user address.

EXAMPLES

List the filesystem types configured in the system.

#include <sys/fstyp.h> 

int max_type, error, i; 
char name[FSTYPSZ]; 
max_type = sysfs(GETNFSTYP); 
for (i = 0; i < max_type; i++) { 
        error = sysfs(GETFSTYP, i, name); 
        if (error == 0) 
                my_print(name); 
} 