Added examples for ioctl functionality. Currently linux dependent.

diff --git a/examples/fioc.pl b/examples/fioc.pl
new file mode 100755 (executable)
index 0000000..031067b
--- /dev/null
+++ b/examples/fioc.pl
@@ -0,0 +1,203 @@
+#!/usr/bin/env perl
+
+use strict;
+no strict qw(refs);
+
+use Carp ();
+local $SIG{'__WARN__'} = \&Carp::cluck;
+
+use Fuse;
+use Fcntl qw(:mode);
+use Errno qw(:POSIX);
+use POSIX;
+
+my $fioc_size = 0;
+use constant FIOC_NAME => 'fioc';
+my $fioc_buf = '';
+use constant FIOC_NONE  => 0;
+use constant FIOC_ROOT  => 1;
+use constant FIOC_FILE  => 2;
+
+sub _IOC_NRBITS  { 8 }
+sub _IOC_NRMASK  { ( 1 << &_IOC_NRBITS ) - 1 }
+sub _IOC_NRSHIFT { 0 }
+
+sub _IOC_TYPEBITS  { 8 }
+sub _IOC_TYPEMASK  { ( 1 << &_IOC_TYPEBITS ) - 1 }
+sub _IOC_TYPESHIFT { &_IOC_NRSHIFT + &_IOC_NRBITS }
+
+sub _IOC_SIZEBITS { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 14 : 13 }
+sub _IOC_SIZEMASK  { ( 1 << &_IOC_SIZEBITS ) - 1 }
+sub _IOC_SIZESHIFT { &_IOC_TYPESHIFT + &_IOC_TYPEBITS }
+
+sub _IOC_DIRBITS  { 32 - &_IOC_NRBITS - &_IOC_TYPEBITS - &_IOC_SIZEBITS }
+sub _IOC_DIRMASK  { ( 1 << &_IOC_DIRBITS ) - 1 }
+sub _IOC_DIRSHIFT { &_IOC_SIZESHIFT + &_IOC_SIZEBITS }
+
+sub _IOC_NONE  { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 0 : 1 }
+sub _IOC_WRITE { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 1 : 4 }
+sub _IOC_READ  { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 2 : 2 }
+
+sub _IOC ($$$$) {
+  ( $_[0] << &_IOC_DIRSHIFT ) |  ( ord( $_[1] ) << &_IOC_TYPESHIFT ) |
+    ( $_[2] << &_IOC_NRSHIFT ) | ( $_[3] << &_IOC_SIZESHIFT );
+}
+
+sub _IO ($$)    { &_IOC( &_IOC_NONE,               $_[0], $_[1], 0 ) }
+sub _IOR ($$$)  { &_IOC( &_IOC_READ,               $_[0], $_[1], $_[2] ) }
+sub _IOW ($$$)  { &_IOC( &_IOC_WRITE,              $_[0], $_[1], $_[2] ) }
+sub _IOWR ($$$) { &_IOC( &_IOC_READ | &_IOC_WRITE, $_[0], $_[1], $_[2] ) }
+
+sub FIOC_GET_SIZE { _IOR('E', 0, 4); }
+sub FIOC_SET_SIZE { _IOW('E', 1, 4); }
+
+sub fioc_resize {
+    my ($size) = @_;
+    print 'called ', (caller(0))[3], "\n";
+    return 0 if $size == $fioc_size;
+    
+    if ($size < $fioc_size) {
+        $fioc_buf = substr($fioc_buf, 0, $size);
+    }
+    else {
+        $fioc_buf .= "\0" x ($size - $fioc_size);
+    }
+    $fioc_size = $size;
+    return 0;
+}
+
+sub fioc_expand {
+    my ($size) = @_;
+    print 'called ', (caller(0))[3], "\n";
+    if ($size > $fioc_size) {
+        return fioc_resize($size);
+    }
+    return 0;
+}
+
+sub fioc_file_type {
+    my ($path) = @_;
+    print 'called ', (caller(0))[3], "\n";
+    return FIOC_ROOT if $path eq '/';
+    return FIOC_FILE if $path eq '/' . FIOC_NAME;
+    return FIOC_NONE;
+}
+
+sub fioc_getattr {
+    my ($path) = @_;
+    print 'called ', (caller(0))[3], "\n";
+    my @stbuf = (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
+
+    $stbuf[4] = $<;
+    $stbuf[5] = (split(/\s+/, $())[0];
+    $stbuf[8] = $stbuf[9] = time();
+
+    my $type = fioc_file_type($path);
+    if ($type == FIOC_ROOT) {
+        $stbuf[2] = S_IFDIR | 0755;
+        $stbuf[3] = 2;
+    }
+    elsif ($type == FIOC_FILE) {
+        $stbuf[2] = S_IFREG | 0644;
+        $stbuf[3] = 1;
+        $stbuf[7] = $fioc_size;
+    }
+    else {
+        return -&ENOENT;
+    }
+    return @stbuf;
+}
+
+sub fioc_open {
+    my ($path, $flags, $info) = @_;
+    print 'called ', (caller(0))[3], "\n";
+
+    if (fioc_file_type($path) != FIOC_NONE) {
+        return 0;
+    }
+    return -&ENOENT;
+}
+
+sub fioc_read {
+    my ($path, $size, $offset) = @_;
+    print 'called ', (caller(0))[3], "\n";
+
+    return -&EINVAL if fioc_file_type($path) != FIOC_FILE;
+
+    if ($offset > $fioc_size) {
+        return q{};
+    }
+
+    if ($size > $fioc_size - $offset) {
+        $size - $fioc_size - $offset;
+    }
+
+    return substr($fioc_buf, $offset, $size);
+}
+
+sub fioc_write {
+    my ($path, $data, $offset) = @_;
+    print 'called ', (caller(0))[3], "\n";
+
+    return -&EINVAL if fioc_file_type($path) != FIOC_FILE;
+
+    if (fioc_expand($offset + length($data))) {
+        return -&ENOMEM;
+    }
+
+    substr($fioc_buf, $offset, length($data), $data);
+    return length($data);
+}
+
+sub fioc_truncate {
+    my ($path, $size) = @_;
+    print 'called ', (caller(0))[3], "\n";
+
+    return -&EINVAL if fioc_file_type($path) != FIOC_FILE;
+
+    return fioc_resize($size);
+}
+
+sub fioc_readdir {
+    my ($path, $offset) = @_;
+    print 'called ', (caller(0))[3], "\n";
+
+    return -&EINVAL if fioc_file_type($path) != FIOC_ROOT;
+
+    return ('.', '..', FIOC_NAME, 0);
+}
+
+sub fioc_ioctl {
+    my ($path, $cmd, $flags, $data) = @_;
+    print 'called ', (caller(0))[3], "\n";
+    $cmd = unpack('L', pack('l', $cmd));
+
+    print("fioc_ioctl(): path is \"$path\", cmd is $cmd, flags is $flags\n");
+    return -&EINVAL if fioc_file_type($path) != FIOC_FILE;
+
+    return -&ENOSYS if $flags & 0x1;
+
+    if ($cmd == FIOC_GET_SIZE) {
+        print "handling FIOC_GET_SIZE\n";
+        return(0, pack('L', $fioc_size));
+    }
+    elsif ($cmd == FIOC_SET_SIZE) {
+        print "handling FIOC_SET_SIZE\n";
+        fioc_resize(unpack('L', $data));
+        return 0;
+    }
+
+    return -&EINVAL;
+}
+
+croak("Fuse doesn't have ioctl") unless Fuse::fuse_version() >= 2.8;
+
+Fuse::main(
+    'mountpoint' => $ARGV[0],
+    'getattr'   => 'main::fioc_getattr',
+    'readdir'   => 'main::fioc_readdir',
+    'truncate'  => 'main::fioc_truncate',
+    'open'      => 'main::fioc_open',
+    'read'      => 'main::fioc_read',
+    'write'     => 'main::fioc_write',
+    'ioctl'     => 'main::fioc_ioctl');

diff --git a/examples/fioclient.pl b/examples/fioclient.pl
new file mode 100755 (executable)
index 0000000..0dc7bfc
--- /dev/null
+++ b/examples/fioclient.pl
@@ -0,0 +1,105 @@
+#!/usr/bin/env perl
+
+use strict;
+no strict qw(refs);
+
+use Carp;
+local $SIG{'__WARN__'} = \&Carp::cluck;
+
+use Fcntl qw(:mode);
+use Errno qw(:POSIX);
+use POSIX;
+
+use constant FIOC_NAME => 'fioc';
+use constant FIOC_NONE  => 0;
+use constant FIOC_ROOT  => 1;
+use constant FIOC_FILE  => 2;
+
+sub _IOC_NRBITS  { 8 }
+sub _IOC_NRMASK  { ( 1 << &_IOC_NRBITS ) - 1 }
+sub _IOC_NRSHIFT { 0 }
+
+sub _IOC_TYPEBITS  { 8 }
+sub _IOC_TYPEMASK  { ( 1 << &_IOC_TYPEBITS ) - 1 }
+sub _IOC_TYPESHIFT { &_IOC_NRSHIFT + &_IOC_NRBITS }
+
+sub _IOC_SIZEBITS { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 14 : 13 }
+sub _IOC_SIZEMASK  { ( 1 << &_IOC_SIZEBITS ) - 1 }
+sub _IOC_SIZESHIFT { &_IOC_TYPESHIFT + &_IOC_TYPEBITS }
+
+sub _IOC_DIRBITS  { 32 - &_IOC_NRBITS - &_IOC_TYPEBITS - &_IOC_SIZEBITS }
+sub _IOC_DIRMASK  { ( 1 << &_IOC_DIRBITS ) - 1 }
+sub _IOC_DIRSHIFT { &_IOC_SIZESHIFT + &_IOC_SIZEBITS }
+
+sub _IOC_NONE  { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 0 : 1 }
+sub _IOC_WRITE { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 1 : 4 }
+sub _IOC_READ  { ( POSIX::uname() )[4] =~ /^i[3-6]86|x86_64$/ ? 2 : 2 }
+
+sub _IOC ($$$$) {
+  ( $_[0] << &_IOC_DIRSHIFT ) |  ( ord( $_[1] ) << &_IOC_TYPESHIFT ) |
+    ( $_[2] << &_IOC_NRSHIFT ) | ( $_[3] << &_IOC_SIZESHIFT );
+}
+
+sub _IO ($$)    { &_IOC( &_IOC_NONE,               $_[0], $_[1], 0 ) }
+sub _IOR ($$$)  { &_IOC( &_IOC_READ,               $_[0], $_[1], $_[2] ) }
+sub _IOW ($$$)  { &_IOC( &_IOC_WRITE,              $_[0], $_[1], $_[2] ) }
+sub _IOWR ($$$) { &_IOC( &_IOC_READ | &_IOC_WRITE, $_[0], $_[1], $_[2] ) }
+
+sub FIOC_GET_SIZE { _IOR('E', 0, 4); }
+sub FIOC_SET_SIZE { _IOW('E', 1, 4); }
+
+sub usage {
+    print <<'_EOT_';
+Usage: fioclient.pl FIOC_FILE COMMAND
+
+COMMANDS
+  s [SIZE]     : get size if SIZE is omitted, set size otherwise
+  r SIZE [OFF] : read SIZE bytes @ OFF (default 0) and output to stdout
+  w SIZE [OFF] : write SIZE bytes @ OFF (default 0) from stdin
+
+_EOT_
+    exit(1);
+}
+
+
+usage() if scalar(@ARGV) < 2;
+
+open(my $file, '+<', $ARGV[0]) or usage();
+
+if ($ARGV[1] eq 's') {
+    if (!defined $ARGV[2]) {
+        my $size;
+        my $rv = ioctl($file, FIOC_GET_SIZE, $size);
+        if (ioctl($file, FIOC_GET_SIZE, $size) != 0) {
+            croak($!);
+        }
+        printf("\%u\n", unpack('L', $size));
+    }
+    else {
+        if (ioctl($file, FIOC_SET_SIZE, pack('L', $ARGV[2])) != 0) {
+            croak($!);
+        }
+    }
+}
+elsif ($ARGV[1] eq 'r' || $ARGV[1] eq 'w') {
+    usage() unless defined $ARGV[2];
+    my $size = $ARGV[2];
+    my $off = 0;
+    if (defined $ARGV[3]) {
+        $off = $ARGV[3];
+    }
+    seek($file, SEEK_SET, $off);
+    if ($ARGV[1] eq 'r') {
+        read($file, my $data, $size);
+        print $data;
+    }
+    else {
+        read(STDIN, my $data, $size);
+        print $file $data;
+    }
+}
+else {
+    usage();
+}
+
+close($file);