mojave man page for 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       This System-V derived system call is obsolete;  don't  use  it.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  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/.

Linux                                                               2017-09-15                                                            SYSFS(2)