linux man page for sysfs

SYSFS(2)						     Linux Programmer's Manual							  SYSFS(2)

NAME
       sysfs - get file system type information

SYNOPSIS
       int sysfs(int option, const char *fsname);

       int sysfs(int option, unsigned int fs_index, char *buf);

       int sysfs(int option);

DESCRIPTION
       sysfs()	returns  information  about  the file system types currently present in the kernel.  The specific form of the sysfs() call and the
       information returned depends on the option in effect:

       1  Translate the file-system identifier string fsname into a file-system type index.

       2  Translate the file-system type index fs_index into a null-terminated file-system identifier string.  This string will be written to  the
	  buffer pointed to by buf.  Make sure that buf has enough space to accept the string.

       3  Return the total number of file system types currently present in the kernel.

       The numbering of the file-system type indexes begins with zero.

RETURN VALUE
       On  success, sysfs() returns the file-system index for option 1, zero for option 2, and the number of currently configured file systems for
       option 3.  On error, -1 is returned, and errno is set appropriately.

ERRORS
       EFAULT Either fsname or buf is outside your accessible address space.

       EINVAL fsname is not a valid file-system type identifier; fs_index is out-of-bounds; option is invalid.

CONFORMING TO
       SVr4.

NOTES
       This System-V derived system call is obsolete;  don't  use  it.	 On  systems  with  /proc,  the  same  information  can  be  obtained  via
       /proc/filesystems; use that interface instead.

BUGS
       There is no libc or glibc support.  There is no way to guess how large buf should be.

COLOPHON
       This  page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2010-06-27								  SYSFS(2)