sysfs

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

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       This  System-V  derived system call is obsolete; don't use it.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 sys-
       tems  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 5.05 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/.

Linux                             2017-09-15                          SYSFS(2)