NAME

     getfsstat — get list of all mounted file systems

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/param.h>
     #include <sys/ucred.h>
     #include <sys/mount.h>

     int
     getfsstat(struct statfs *buf, long bufsize, int mode);

DESCRIPTION

     The getfsstat() system call returns information about all mounted file systems.  The buf
     argument is a pointer to statfs structures, as described in statfs(2).

     Fields that are undefined for a particular file system are set to -1.  The buffer is filled
     with an array of statfs structures, one for each mounted file system up to the byte count
     specified by bufsize.  Note, the bufsize argument is the number of bytes that buf can hold,
     not the count of statfs structures it will hold.

     If buf is given as NULL, getfsstat() returns just the number of mounted file systems.

     Normally mode should be specified as MNT_WAIT.  If mode is set to MNT_NOWAIT, getfsstat()
     will return the information it has available without requesting an update from each file
     system.  Thus, some of the information will be out of date, but getfsstat() will not block
     waiting for information from a file system that is unable to respond.  It will also skip any
     file system that is in the process of being unmounted, even if the unmount would eventually
     fail.

RETURN VALUES

     Upon successful completion, the number of statfs structures is returned.  Otherwise, -1 is
     returned and the global variable errno is set to indicate the error.

ERRORS

     The getfsstat() system call fails if one or more of the following are true:

     [EFAULT]           The buf argument points to an invalid address.

     [EINVAL]           mode is set to a value other than MNT_WAIT or MNT_NOWAIT.

     [EIO]              An I/O error occurred while reading from or writing to the file system.

SEE ALSO

     statfs(2), fstab(5), mount(8)

HISTORY

     The getfsstat() system call first appeared in 4.4BSD.