getfsstat - Gets list of all mounted file systems
struct statfs buf,
int flags );
buf An array of statfs structures.
bufsize Specifies the size in bytes of the buf parameter.
flags Specifies one of the following flags:
MNT_WAIT Wait for an update from each file system before return-
Information is returned without requesting an update
from each file system. Thus, some of the information
will be out of date, but the getfsstat() function will
not block waiting for information from a file system
that is unable to respond.
The getfsstat() function returns information about all mounted file sys-
tems. Upon successful completion, the buffer pointed to by the buf parame-
ter is filled with an array of statfs structures, one for each mounted file
system up to the size specified by the bufsize parameter.
If the buf parameter is given as 0 (zero), the getfsstat() function returns
just the number of mounted file systems.
Upon successful completion, the number of statfs structures is returned.
Otherwise, -1 is returned and errno is set to indicate the error.
If the getfsstat() function fails, errno may be set to one of the following
[EFAULT] The buf parameter points to an invalid address.
[EIO] An I/O error occurred while reading from or writing to the file