sysfs - get information on file system type (extension)

Syntax	#include <sys/fstyp.h> #include <sys/fsid.h> int sysfs(int opcode[, const char *fsname]| [, int fs_index, char *buf]);
Description	sysfs() returns information on the file system types configured in the system. The number of arguments accepted by sysfs() depends on the value of opcode. The following values for opcode are accepted in the C runtime system:
	GETFSIND	Translates fsname, a null-terminated file-system identifier, into a file-system type index.
	GETFSTYP	Translates fs_index, a file-system type index, into a null-terminated file-system identifier and writes it into the buffer pointed to by buf. This buffer must be at least of size FSTYPSZ (see sys/fstyp.h).
	GETNFSTYP	Returns the total number of file system types configured in the system.
Return val.	File system type index
		if opcode is GETFSIND; upon successful completion.
	0	if opcode is GETFSTYP; upon successful completion.
	Number of file system types configured
		if opcode is GETNFSTYP; upon successful completion.
	-1	if unsuccessful. errno is set to indicate the error.
Errors	sysfs() will fail if:
	EINVAL	fsname points to an invalid file-system identifier; fs_index is zero or invalid or opcode is invalid or an attempt was made to access a BS2000 file.
	EFAULT	buf or fsname points outside the allocated address space for the process.
Notes	sysfs() is executed only for POSIX files.
See also	sys/fstyp.h, sys/fsid.h.