| package Fuse; |
| |
| use 5.006; |
| use strict; |
| use warnings; |
| use Errno; |
| use Carp; |
| |
| require Exporter; |
| require DynaLoader; |
| use AutoLoader; |
| use Data::Dumper; |
| our @ISA = qw(Exporter DynaLoader); |
| |
| # Items to export into callers namespace by default. Note: do not export |
| # names by default without a very good reason. Use EXPORT_OK instead. |
| # Do not simply export all your public functions/methods/constants. |
| |
| # This allows declaration use Fuse ':all'; |
| # If you do not need this, moving things directly into @EXPORT or @EXPORT_OK |
| # will save memory. |
| our %EXPORT_TAGS = ( 'all' => [ qw( |
| FUSE_DEBUG |
| ) ] ); |
| |
| our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } ); |
| |
| our @EXPORT = qw( |
| FUSE_DEBUG |
| ); |
| our $VERSION = '0.01'; |
| |
| sub AUTOLOAD { |
| # This AUTOLOAD is used to 'autoload' constants from the constant() |
| # XS function. If a constant is not found then control is passed |
| # to the AUTOLOAD in AutoLoader. |
| |
| my $constname; |
| our $AUTOLOAD; |
| ($constname = $AUTOLOAD) =~ s/.*:://; |
| croak "& not defined" if $constname eq 'constant'; |
| my $val = constant($constname, @_ ? $_[0] : 0); |
| if ($! != 0) { |
| if ($!{EINVAL}) { |
| $AutoLoader::AUTOLOAD = $AUTOLOAD; |
| goto &AutoLoader::AUTOLOAD; |
| } |
| else { |
| croak "Your vendor has not defined Fuse macro $constname"; |
| } |
| } |
| { |
| no strict 'refs'; |
| # Fixed between 5.005_53 and 5.005_61 |
| if ($] >= 5.00561) { |
| *$AUTOLOAD = sub () { $val }; |
| } |
| else { |
| *$AUTOLOAD = sub { $val }; |
| } |
| } |
| goto &$AUTOLOAD; |
| } |
| |
| bootstrap Fuse $VERSION; |
| |
| sub main { |
| my (@subs) = (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0); |
| my (@names) = qw(getattr readlink getdir mknod mkdir unlink rmdir symlink rename link chmod chown truncate utime open read write statfs); |
| my ($tmp) = 0; |
| my (%mapping) = map { $_ => $tmp++ } (@names); |
| my (%otherargs) = (debug=>0, threaded=>1, mountpoint=>""); |
| while(my $name = shift) { |
| my ($subref) = shift; |
| if(exists($otherargs{$name})) { |
| $otherargs{$name} = $subref; |
| } else { |
| croak "There is no function $name" unless exists($mapping{$name}); |
| croak "Usage: Fuse::main(getattr => &my_getattr, ...)" unless $subref; |
| croak "Usage: Fuse::main(getattr => &my_getattr, ...)" unless ref($subref); |
| croak "Usage: Fuse::main(getattr => &my_getattr, ...)" unless ref($subref) eq "CODE"; |
| $subs[$mapping{$name}] = $subref; |
| } |
| } |
| perl_fuse_main($0,$otherargs{threaded},$otherargs{debug},$otherargs{mountpoint},@subs); |
| } |
| |
| # Autoload methods go after =cut, and are processed by the autosplit program. |
| |
| 1; |
| __END__ |
| |
| =head1 NAME |
| |
| Fuse - write filesystems in Perl using FUSE |
| |
| =head1 SYNOPSIS |
| |
| use Fuse; |
| my ($mountpoint) = ""; |
| $mountpoint = shift(@ARGV) if @ARGV; |
| Fuse::main(mountpoint=>$mountpoint, getattr=>\&my_getattr, getdir=>\&my_getdir, ...); |
| |
| =head1 DESCRIPTION |
| |
| This lets you implement filesystems in perl, through the FUSE |
| (Filesystem in USErspace) kernel/lib interface. |
| |
| FUSE expects you to implement callbacks for the various functions. |
| |
| NOTE: I have only tested the things implemented in example.pl! |
| It should work, but some things may not. |
| |
| In the following definitions, "errno" can be 0 (for a success), |
| -EINVAL, -ENOENT, -EONFIRE, any integer less than 1 really. |
| |
| You can import standard error constants by saying something like |
| "use POSIX qw(EDOTDOT ENOANO);". |
| |
| Every constant you need (file types, open() flags, error values, |
| etc) can be imported either from POSIX or from Fcntl, often both. |
| See their respective documentations, for more information. |
| |
| =head2 EXPORT |
| |
| None by default. |
| |
| =head2 EXPORTABLE CONSTANTS |
| |
| None. |
| |
| =head2 FUNCTIONS YOUR FILESYSTEM MAY IMPLEMENT |
| |
| =head3 getattr |
| |
| Arguments: filename. |
| Returns a list, very similar to the 'stat' function (see |
| perlfunc). On error, simply return a single numeric scalar |
| value (e.g. "return -ENOENT();"). |
| |
| FIXME: the "ino" field is currently ignored. I tried setting it to 0 |
| in an example script, which consistently caused segfaults. |
| |
| Fields (the following was stolen from perlfunc(1) with apologies): |
| |
| ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size, |
| $atime,$mtime,$ctime,$blksize,$blocks) |
| = getattr($filename); |
| |
| Here are the meaning of the fields: |
| |
| 0 dev device number of filesystem |
| 1 ino inode number |
| 2 mode file mode (type and permissions) |
| 3 nlink number of (hard) links to the file |
| 4 uid numeric user ID of file's owner |
| 5 gid numeric group ID of file's owner |
| 6 rdev the device identifier (special files only) |
| 7 size total size of file, in bytes |
| 8 atime last access time in seconds since the epoch |
| 9 mtime last modify time in seconds since the epoch |
| 10 ctime inode change time (NOT creation time!) in seconds |
| since the epoch |
| 11 blksize preferred block size for file system I/O |
| 12 blocks actual number of blocks allocated |
| |
| (The epoch was at 00:00 January 1, 1970 GMT.) |
| |
| =head3 readlink |
| |
| Arguments: link pathname. |
| Returns a scalar: either a numeric constant, or a text string. |
| |
| This is called when dereferencing symbolic links, to learn the target. |
| |
| example rv: return "/proc/self/fd/stdin"; |
| |
| =head3 getdir |
| |
| Arguments: Containing directory name. |
| Returns a list: 0 or more text strings (the filenames), followed by a numeric errno (usually 0). |
| |
| This is used to obtain directory listings. Its opendir(), readdir(), filldir() and closedir() all in one call. |
| |
| example rv: return ('.', 'a', 'b', 0); |
| |
| =head3 mknod |
| |
| Arguments: Filename, numeric modes, numeric device |
| Returns an errno (0 upon success, as usual). |
| |
| This function is called for all non-directory, non-symlink nodes, |
| not just devices. |
| |
| =head3 mkdir |
| |
| Arguments: New directory pathname, numeric modes. |
| Returns an errno. |
| |
| Called to create a directory. |
| |
| =head3 unlink |
| |
| Arguments: Filename. |
| Returns an errno. |
| |
| Called to remove a file, device, or symlink. |
| |
| =head3 rmdir |
| |
| Arguments: Pathname. |
| Returns an errno. |
| |
| Called to remove a directory. |
| |
| =head3 symlink |
| |
| Arguments: Existing filename, symlink name. |
| Returns an errno. |
| |
| Called to create a symbolic link. |
| |
| =head3 rename |
| |
| Arguments: old filename, new filename. |
| Returns an errno. |
| |
| Called to rename a file, and/or move a file from one directory to another. |
| |
| =head3 link |
| |
| Arguments: Existing filename, hardlink name. |
| Returns an errno. |
| |
| Called to create hard links. |
| |
| =head3 chmod |
| |
| Arguments: Pathname, numeric modes. |
| Returns an errno. |
| |
| Called to change permissions on a file/directory/device/symlink. |
| |
| =head3 chown |
| |
| Arguments: Pathname, numeric uid, numeric gid. |
| Returns an errno. |
| |
| Called to change ownership of a file/directory/device/symlink. |
| |
| =head3 truncate |
| |
| Arguments: Pathname, numeric offset. |
| Returns an errno. |
| |
| Called to truncate a file, at the given offset. |
| |
| =head3 utime |
| |
| Arguments: Pathname, numeric actime, numeric modtime. |
| Returns an errno. |
| |
| Called to change access/modification times for a file/directory/device/symlink. |
| |
| =head3 open |
| |
| Arguments: Pathname, numeric flags (which is an OR-ing of stuff like O_RDONLY |
| and O_SYNC, constants you can import from POSIX). |
| Returns an errno. |
| |
| No creation, or trunctation flags (O_CREAT, O_EXCL, O_TRUNC) will be passed to open(). |
| Your open() method needs only check if the operation is permitted for the given flags, and return 0 for success. |
| |
| =head3 read |
| |
| Arguments: Pathname, numeric requestedsize, numeric offset. |
| Returns a numeric errno, or a string scalar with up to $requestedsize bytes of data. |
| |
| Called in an attempt to fetch a portion of the file. |
| |
| =head3 write |
| |
| Arguments: Pathname, scalar buffer, numeric offset. You can use length($buffer) to |
| find the buffersize. |
| Returns an errno. |
| |
| Called in an attempt to write (or overwrite) a portion of the file. Be prepared because $buffer could contain random binary data with NULLs and all sorts of other wonderful stuff. |
| |
| =head3 statfs |
| |
| Arguments: none |
| Returns any of the following: |
| |
| -ENOANO() |
| |
| or |
| |
| $namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize |
| |
| or |
| |
| -ENOANO(), $namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize |
| |
| =head1 AUTHOR |
| |
| Mark Glines, E<lt>mark@glines.orgE<gt> |
| |
| =head1 SEE ALSO |
| |
| L<perl>, the FUSE documentation. |
| |
| =cut |