NAME

       sysfs - get filesystem 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

       Note:  if  you  are  looking  for  information about the sysfs filesystem that is normally
       mounted at /sys, see sysfs(5).

       The (obsolete)  sysfs()  system  call  returns  information  about  the  filesystem  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 filesystem identifier string fsname into a filesystem type index.

       2  Translate  the  filesystem  type  index  fs_index  into  a  null-terminated  filesystem
          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 filesystem types currently present in the kernel.

       The numbering of the filesystem type indexes begins with zero.

RETURN VALUE

       On success, sysfs() returns the filesystem index for option 1, zero for option 2, and  the
       number  of  currently  configured filesystems 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 filesystem 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       This  System-V  derived system call is obsolete; don't use it.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 4.15 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at https://www.kernel.org/doc/man-pages/.