a2p
accept
access
acct
addftinfo
addr2line
adjtime
afmtodit
after
aio_cancel
aio_error
aio_read
aio_return
aio_suspend
aio_waitcomplete
aio_write
alias
aliases
alloc
anvil
append
apply
apropos
ar
array
as
asa
asn1parse
at
atq
atrm
attemptckalloc
attemptckrealloc
authlib
authtest
autopoint
awk
b64decode
b64encode
basename
batch
bc
bdes
bell
bg
bgerror
biff
big5
binary
bind
bindkey
bindtags
bindtextdomain
bio
bitmap
blowfish
bn
bootparams
bootptab
bounce
brandelf
break
breaksw
brk
bsdiff
bsdtar
bsnmpd
bspatch
bthost
btsockstat
buffer
builtin
builtins
bunzip2
button
byacc
bzcat
bzegrep
bzfgrep
bzgrep
bzip2
c2ph
c89
c99
ca
cal
calendar
canvas
cap_mkdb
case
cat
catch
catman
cc
cd
cdcontrol
chdir
checkbutton
checknr
chflags
chfn
chgrp
chio
chkey
chmod
chown
chpass
chroot
chsh
ci
ciphers
ckalloc
ckdist
ckfree
ckrealloc
cksum
cleanup
clear
clipboard
clock
clock_getres
clock_gettime
clock_settime
close
cmp
co
col
colcrt
colldef
colors
colrm
column
comm
command
compile_et
complete
compress
concat
config
connect
console
continue
core
courierlogger
couriertcpd
cp
cpan
cpio
cpp
creat
crl
crontab
crunchgen
crunchide
crypt
crypto
csh
csplit
ctags
ctm
ctm_dequeue
ctm_rmail
ctm_smail
cu
cursor
cursors
cut
cvs
date
dbiprof
dbiproxy
dc
dcgettext
dcngettext
dd
dde
default
defer
deliverquota
des
destroy
devfs
df
dgettext
dgst
dh
dhparam
dialog
diff
diff3
dig
dir
dirent
dirname
dirs
discard
disktab
dngettext
do
domainname
done
dprofpp
dsa
dsaparam
dtmfdecode
du
dup
dup2
eaccess
ec
ecdsa
echo
echotc
ecparam
ed
edit
editrc
ee
egrep
elf
elfdump
elif
else
enc
enc2xs
encoding
end
endif
endsw
engine
enigma
entry
env
envsubst
eof
eqn
err
errno
error
errstr
esac
ethers
euc
eui64
eval
event
evp
ex
exec
execve
exit
expand
export
exports
expr
extattr
extattr_delete_fd
extattr_delete_file
extattr_get_fd
extattr_get_file
extattr_set_fd
extattr_set_file
f77
false
famm
famx
fblocked
fbtab
fc
fchdir
fchflags
fchmod
fchown
fcntl
fconfigure
fcopy
fdescfs
fdformat
fdread
fdwrite
fetch
fg
fgrep
fhopen
fhstat
fhstatfs
fi
file
file2c
fileevent
filename
filetest
find
find2perl
finger
flex
flock
flush
fmt
focus
fold
font
fontedit
for
foreach
fork
format
forward
fpathconf
frame
from
fs
fstab
fstat
fstatfs
fsync
ftp
ftpchroot
ftpusers
ftruncate
futimes
g711conv
gb2312
gb18030
gbk
gcc
gcore
gcov
gdb
gencat
gendsa
genrsa
gensnmptree
getconf
getdents
getdirentries
getdtablesize
getegid
geteuid
getfacl
getfh
getfsstat
getgid
getgroups
getitimer
getlogin
getopt
getopts
getpeername
getpgid
getpgrp
getpid
getppid
getpriority
getresgid
getresuid
getrlimit
getrusage
gets
getsid
getsockname
getsockopt
gettext
gettextize
gettimeofday
gettytab
getuid
glob
global
gmake
goto
gperf
gprof
grab
grep
grid
grn
grodvi
groff
groff_font
groff_out
groff_tmac
grog
grolbp
grolj4
grops
grotty
group
groups
gunzip
gzcat
gzexe
gzip
h2ph
h2xs
hash
hashstat
hd
head
help2man
hesinfo
hexdump
history
host
hostname
hosts
hosts_access
hosts_options
hpftodit
http
hup
i386_get_ioperm
i386_get_ldt
i386_set_ioperm
i386_set_ldt
i386_vm86
iconv
id
ident
idprio
if
ifnames253
ifnames259
image
imapd
incr
indent
indxbib
info
infokey
inode
install
instmodsh
interp
intro
introduction
ioctl
ipcrm
ipcs
ipf
ipftest
ipnat
ippool
ipresend
issetugid
jail
jail_attach
jobid
jobs
join
jot
kbdcontrol
kbdmap
kcon
kdestroy
kdump
kenv
kevent
keycap
keylogin
keylogout
keymap
keysyms
kgdb
kill
killall
killpg
kinit
kldfind
kldfirstmod
kldload
kldnext
kldstat
kldsym
kldunload
klist
kpasswd
kqueue
kse
kse_create
kse_exit
kse_release
kse_switchin
kse_thr_interrupt
kse_wakeup
ktrace
label
labelframe
lam
lappend
last
lastcomm
lastlog
lchflags
lchmod
lchown
ld
ldap
ldapadd
ldapcompare
ldapdelete
ldapmodify
ldapmodrdn
ldappasswd
ldapsearch
ldapwhoami
ldd
leave
less
lesskey
lex
lgetfh
lhash
libnetcfg
library
limit
limits
lindex
link
linprocfs
linsert
lint
lio_listio
list
listbox
listen
lj4_font
lkbib
llength
lmtp
ln
load
loadfont
local
locale
locate
lock
lockf
log
logger
login
logins
logname
logout
look
lookbib
lorder
lower
lp
lpq
lpr
lprm
lptest
lrange
lreplace
ls
lsearch
lseek
lset
lsort
lstat
lsvfs
lutimes
lynx
m4
madvise
magic
mail
maildiracl
maildirkw
maildirmake
mailq
mailx
make
makeinfo
makewhatis
man
manpath
master
mc
mcedit
mcview
md2
md4
md5
mdc2
memory
menu
menubar
menubutton
merge
mesg
message
mincore
minherit
minigzip
mkdep
mkdir
mkfifo
mkimapdcert
mklocale
mknod
mkpop3dcert
mkstr
mktemp
mlock
mlockall
mmap
mmroff
modfind
modfnext
modnext
modstat
moduli
more
motd
mount
mprotect
mptable
msdos
msdosfs
msgattrib
msgcat
msgcmp
msgcomm
msgconv
msgen
msgexec
msgfilter
msgfmt
msggrep
msginit
msgmerge
msgs
msgunfmt
msguniq
mskanji
msql2mysql
msync
mt
munlock
munlockall
munmap
mv
myisamchk
myisamlog
myisampack
mysql
mysqlaccess
mysqladmin
mysqlbinlog
mysqlcheck
mysqld
mysqldump
mysqld_multi
mysqld_safe
mysqlhotcopy
mysqlimport
mysqlshow
mysql_config
mysql_fix_privilege_tables
mysql_zap
namespace
nanosleep
nawk
nc
ncal
ncplist
ncplogin
ncplogout
neqn
netconfig
netgroup
netid
netstat
networks
newaliases
newgrp
nex
nfsstat
nfssvc
ngettext
nice
nl
nm
nmount
nohup
nologin
notify
nroff
nseq
nslookup
ntp_adjtime
ntp_gettime
nvi
nview
objcopy
objdump
objformat
ocsp
od
onintr
open
openssl
opieaccess
opieinfo
opiekey
opiekeys
opiepasswd
option
options
oqmgr
pack
package
packagens
pagesize
palette
pam_auth
panedwindow
parray
passwd
paste
patch
pathchk
pathconf
pawd
pax
pbm
pcre
pcreapi
pcrebuild
pcrecallout
pcrecompat
pcrecpp
pcregrep
pcrematching
pcrepartial
pcrepattern
pcreperform
pcreposix
pcreprecompile
pcresample
pcretest
perl
perl56delta
perl58delta
perl561delta
perl570delta
perl571delta
perl572delta
perl573delta
perl581delta
perl582delta
perl583delta
perl584delta
perl585delta
perl586delta
perl587delta
perl588delta
perl5004delta
perl5005delta
perlaix
perlamiga
perlapi
perlapio
perlapollo
perlartistic
perlbeos
perlbook
perlboot
perlbot
perlbs2000
perlbug
perlcall
perlcc
perlce
perlcheat
perlclib
perlcn
perlcompile
perlcygwin
perldata
perldbmfilter
perldebguts
perldebtut
perldebug
perldelta
perldgux
perldiag
perldoc
perldos
perldsc
perlebcdic
perlembed
perlepoc
perlfaq
perlfaq1
perlfaq2
perlfaq3
perlfaq4
perlfaq5
perlfaq6
perlfaq7
perlfaq8
perlfaq9
perlfilter
perlfork
perlform
perlfreebsd
perlfunc
perlglossary
perlgpl
perlguts
perlhack
perlhist
perlhpux
perlhurd
perlintern
perlintro
perliol
perlipc
perlirix
perlivp
perljp
perlko
perllexwarn
perllinux
perllocale
perllol
perlmachten
perlmacos
perlmacosx
perlmint
perlmod
perlmodinstall
perlmodlib
perlmodstyle
perlmpeix
perlnetware
perlnewmod
perlnumber
perlobj
perlop
perlopenbsd
perlopentut
perlos2
perlos390
perlos400
perlothrtut
perlpacktut
perlplan9
perlpod
perlpodspec
perlport
perlqnx
perlre
perlref
perlreftut
perlrequick
perlreref
perlretut
perlrun
perlsec
perlsolaris
perlstyle
perlsub
perlsyn
perlthrtut
perltie
perltoc
perltodo
perltooc
perltoot
perltrap
perltru64
perltw
perlunicode
perluniintro
perlutil
perluts
perlvar
perlvmesa
perlvms
perlvos
perlwin32
perlxs
perlxstut
perror
pfbtops
pftp
pgrep
phones
photo
pic
pickup
piconv
pid
pipe
pkcs7
pkcs8
pkcs12
pkg_add
pkg_check
pkg_create
pkg_delete
pkg_info
pkg_sign
pkg_version
pkill
pl2pm
place
pod2html
pod2latex
pod2man
pod2text
pod2usage
podchecker
podselect
poll
popd
popup
posix_madvise
postalias
postcat
postconf
postdrop
postfix
postkick
postlock
postlog
postmap
postqueue
postsuper
pr
pread
preadv
printcap
printenv
printf
proc
procfs
profil
protocols
prove
proxymap
ps
psed
psroff
pstruct
ptrace
publickey
pushd
puts
pwd
pwrite
pwritev
qmgr
qmqpd
quota
quotactl
radiobutton
raise
rand
ranlib
rcp
rcs
rcsclean
rcsdiff
rcsfile
rcsfreeze
rcsintro
rcsmerge
read
readelf
readlink
readonly
readv
realpath
reboot
recv
recvfrom
recvmsg
red
ree
refer
regexp
registry
regsub
rehash
remote
rename
repeat
replace
req
reset
resolver
resource
return
rev
revoke
rfcomm_sppd
rfork
rhosts
ripemd
ripemd160
rlog
rlogin
rm
rmd160
rmdir
rpc
rpcgen
rs
rsa
rsautl
rsh
rtld
rtprio
rup
ruptime
rusers
rwall
rwho
s2p
safe
sasl
sasldblistusers2
saslpasswd2
sbrk
scache
scale
scan
sched
sched_getparam
sched_getscheduler
sched_get_priority_max
sched_get_priority_min
sched_rr_get_interval
sched_setparam
sched_setscheduler
sched_yield
scon
scp
script
scrollbar
sdiff
sed
seek
select
selection
semctl
semget
semop
send
sendbug
sendfile
sendmail
sendmsg
sendto
services
sess_id
set
setegid
setenv
seteuid
setfacl
setgid
setgroups
setitimer
setlogin
setpgid
setpgrp
setpriority
setregid
setresgid
setresuid
setreuid
setrlimit
setsid
setsockopt
settc
settimeofday
setty
setuid
setvar
sftp
sh
sha
sha1
sha256
shar
shells
shift
shmat
shmctl
shmdt
shmget
showq
shutdown
sigaction
sigaltstack
sigblock
sigmask
sigpause
sigpending
sigprocmask
sigreturn
sigsetmask
sigstack
sigsuspend
sigvec
sigwait
size
slapadd
slapcat
slapd
slapdn
slapindex
slappasswd
slaptest
sleep
slogin
slurpd
smbutil
smime
smtp
smtpd
socket
socketpair
sockstat
soelim
sort
source
spawn
speed
spinbox
spkac
splain
split
squid
squid_ldap_auth
squid_ldap_group
squid_unix_group
sscop
ssh
sshd_config
ssh_config
stab
startslip
stat
statfs
stop
string
strings
strip
stty
su
subst
sum
suspend
swapoff
swapon
switch
symlink
sync
sysarch
syscall
sysconftool
sysconftoolcheck
systat
s_client
s_server
s_time
tabs
tail
talk
tar
tbl
tclsh
tcltest
tclvars
tcopy
tcpdump
tcpslice
tcsh
tee
tell
telltc
telnet
term
termcap
terminfo
test
texindex
texinfo
text
textdomain
tfmtodit
tftp
then
threads
time
tip
tk
tkerror
tkvars
tkwait
tlsmgr
tmac
top
toplevel
touch
tput
tr
trace
trafshow
trap
troff
true
truncate
truss
tset
tsort
tty
ttys
type
tzfile
ui
ul
ulimit
umask
unalias
uname
uncomplete
uncompress
undelete
unexpand
unhash
unifdef
unifdefall
uniq
units
unknown
unlimit
unlink
unmount
unset
unsetenv
until
unvis
update
uplevel
uptime
upvar
usbhidaction
usbhidctl
users
utf8
utimes
utmp
utrace
uudecode
uuencode
uuidgen
vacation
variable
verify
version
vfork
vgrind
vgrindefs
vi
vidcontrol
vidfont
view
virtual
vis
vt220keys
vwait
w
wait
wait3
wait4
waitpid
wall
wc
wget
what
whatis
where
whereis
which
while
who
whoami
whois
window
winfo
wish
wm
write
writev
wtmp
x509
xargs
xgettext
xmlwf
xstr
xsubpp
yacc
yes
ypcat
ypchfn
ypchpass
ypchsh
ypmatch
yppasswd
ypwhich
yyfix
zcat
zcmp
zdiff
zegrep
zfgrep
zforce
zgrep
zmore
znew
_exit
__syscall
 
FreeBSD/Linux/UNIX General Commands Manual
Hypertext Man Pages
perltie
 
PERLTIE(1)	       Perl Programmers Reference Guide 	    PERLTIE(1)



NAME
       perltie - how to hide an object class in a simple variable

SYNOPSIS
	tie VARIABLE, CLASSNAME, LIST

	$object = tied VARIABLE

	untie VARIABLE

DESCRIPTION
       Prior to release 5.0 of Perl, a programmer could use dbmopen() to con-
       nect an on-disk database in the standard Unix dbm(3x) format magically
       to a %HASH in their program.  However, their Perl was either built with
       one particular dbm library or another, but not both, and you couldn't
       extend this mechanism to other packages or types of variables.

       Now you can.

       The tie() function binds a variable to a class (package) that will pro-
       vide the implementation for access methods for that variable.  Once
       this magic has been performed, accessing a tied variable automatically
       triggers method calls in the proper class.  The complexity of the class
       is hidden behind magic methods calls.  The method names are in ALL
       CAPS, which is a convention that Perl uses to indicate that they're
       called implicitly rather than explicitly--just like the BEGIN() and
       END() functions.

       In the tie() call, "VARIABLE" is the name of the variable to be
       enchanted.  "CLASSNAME" is the name of a class implementing objects of
       the correct type.  Any additional arguments in the "LIST" are passed to
       the appropriate constructor method for that class--meaning TIESCALAR(),
       TIEARRAY(), TIEHASH(), or TIEHANDLE().  (Typically these are arguments
       such as might be passed to the dbminit() function of C.) The object
       returned by the "new" method is also returned by the tie() function,
       which would be useful if you wanted to access other methods in "CLASS-
       NAME". (You don't actually have to return a reference to a right "type"
       (e.g., HASH or "CLASSNAME") so long as it's a properly blessed object.)
       You can also retrieve a reference to the underlying object using the
       tied() function.

       Unlike dbmopen(), the tie() function will not "use" or "require" a mod-
       ule for you--you need to do that explicitly yourself.

       Tying Scalars

       A class implementing a tied scalar should define the following methods:
       TIESCALAR, FETCH, STORE, and possibly UNTIE and/or DESTROY.

       Let's look at each in turn, using as an example a tie class for scalars
       that allows the user to do something like:

	   tie $his_speed, 'Nice', getppid();
	   tie $my_speed,  'Nice', $$;

       And now whenever either of those variables is accessed, its current
       system priority is retrieved and returned.  If those variables are set,
       then the process's priority is changed!

       We'll use Jarkko Hietaniemi <jhi@iki.fi>'s BSD::Resource class (not
       included) to access the PRIO_PROCESS, PRIO_MIN, and PRIO_MAX constants
       from your system, as well as the getpriority() and setpriority() system
       calls.  Here's the preamble of the class.

	   package Nice;
	   use Carp;
	   use BSD::Resource;
	   use strict;
	   $Nice::DEBUG = 0 unless defined $Nice::DEBUG;

       TIESCALAR classname, LIST
	   This is the constructor for the class.  That means it is expected
	   to return a blessed reference to a new scalar (probably anonymous)
	   that it's creating.	For example:

	       sub TIESCALAR {
		   my $class = shift;
		   my $pid = shift || $$; # 0 means me

		   if ($pid !~ /^\d+$/) {
		       carp "Nice::Tie::Scalar got non-numeric pid $pid" if $^W;
		       return undef;
		   }

		   unless (kill 0, $pid) { # EPERM or ERSCH, no doubt
		       carp "Nice::Tie::Scalar got bad pid $pid: $!" if $^W;
		       return undef;
		   }

		   return bless \$pid, $class;
	       }

	   This tie class has chosen to return an error rather than raising an
	   exception if its constructor should fail.  While this is how
	   dbmopen() works, other classes may well not wish to be so forgiv-
	   ing.  It checks the global variable $^W to see whether to emit a
	   bit of noise anyway.

       FETCH this
	   This method will be triggered every time the tied variable is
	   accessed (read).  It takes no arguments beyond its self reference,
	   which is the object representing the scalar we're dealing with.
	   Because in this case we're using just a SCALAR ref for the tied
	   scalar object, a simple $$self allows the method to get at the real
	   value stored there.	In our example below, that real value is the
	   process ID to which we've tied our variable.

	       sub FETCH {
		   my $self = shift;
		   confess "wrong type" unless ref $self;
		   croak "usage error" if @_;
		   my $nicety;
		   local($!) = 0;
		   $nicety = getpriority(PRIO_PROCESS, $$self);
		   if ($!) { croak "getpriority failed: $!" }
		   return $nicety;
	       }

	   This time we've decided to blow up (raise an exception) if the
	   renice fails--there's no place for us to return an error otherwise,
	   and it's probably the right thing to do.

       STORE this, value
	   This method will be triggered every time the tied variable is set
	   (assigned).	Beyond its self reference, it also expects one (and
	   only one) argument--the new value the user is trying to assign.
	   Don't worry about returning a value from STORE -- the semantic of
	   assignment returning the assigned value is implemented with FETCH.

	       sub STORE {
		   my $self = shift;
		   confess "wrong type" unless ref $self;
		   my $new_nicety = shift;
		   croak "usage error" if @_;

		   if ($new_nicety < PRIO_MIN) {
		       carp sprintf
			 "WARNING: priority %d less than minimum system priority %d",
			     $new_nicety, PRIO_MIN if $^W;
		       $new_nicety = PRIO_MIN;
		   }

		   if ($new_nicety > PRIO_MAX) {
		       carp sprintf
			 "WARNING: priority %d greater than maximum system priority %d",
			     $new_nicety, PRIO_MAX if $^W;
		       $new_nicety = PRIO_MAX;
		   }

		   unless (defined setpriority(PRIO_PROCESS, $$self, $new_nicety)) {
		       confess "setpriority failed: $!";
		   }
	       }

       UNTIE this
	   This method will be triggered when the "untie" occurs. This can be
	   useful if the class needs to know when no further calls will be
	   made. (Except DESTROY of course.) See "The "untie" Gotcha" below
	   for more details.

       DESTROY this
	   This method will be triggered when the tied variable needs to be
	   destructed.	As with other object classes, such a method is seldom
	   necessary, because Perl deallocates its moribund object's memory
	   for you automatically--this isn't C++, you know.  We'll use a
	   DESTROY method here for debugging purposes only.

	       sub DESTROY {
		   my $self = shift;
		   confess "wrong type" unless ref $self;
		   carp "[ Nice::DESTROY pid $$self ]" if $Nice::DEBUG;
	       }

       That's about all there is to it.  Actually, it's more than all there is
       to it, because we've done a few nice things here for the sake of com-
       pleteness, robustness, and general aesthetics.  Simpler TIESCALAR
       classes are certainly possible.

       Tying Arrays

       A class implementing a tied ordinary array should define the following
       methods: TIEARRAY, FETCH, STORE, FETCHSIZE, STORESIZE and perhaps UNTIE
       and/or DESTROY.

       FETCHSIZE and STORESIZE are used to provide $#array and equivalent
       "scalar(@array)" access.

       The methods POP, PUSH, SHIFT, UNSHIFT, SPLICE, DELETE, and EXISTS are
       required if the perl operator with the corresponding (but lowercase)
       name is to operate on the tied array. The Tie::Array class can be used
       as a base class to implement the first five of these in terms of the
       basic methods above.  The default implementations of DELETE and EXISTS
       in Tie::Array simply "croak".

       In addition EXTEND will be called when perl would have pre-extended
       allocation in a real array.

       For this discussion, we'll implement an array whose elements are a
       fixed size at creation.	If you try to create an element larger than
       the fixed size, you'll take an exception.  For example:

	   use FixedElem_Array;
	   tie @array, 'FixedElem_Array', 3;
	   $array[0] = 'cat';  # ok.
	   $array[1] = 'dogs'; # exception, length('dogs') > 3.

       The preamble code for the class is as follows:

	   package FixedElem_Array;
	   use Carp;
	   use strict;

       TIEARRAY classname, LIST
	   This is the constructor for the class.  That means it is expected
	   to return a blessed reference through which the new array (probably
	   an anonymous ARRAY ref) will be accessed.

	   In our example, just to show you that you don't really have to
	   return an ARRAY reference, we'll choose a HASH reference to repre-
	   sent our object.  A HASH works out well as a generic record type:
	   the "{ELEMSIZE}" field will store the maximum element size allowed,
	   and the "{ARRAY}" field will hold the true ARRAY ref.  If someone
	   outside the class tries to dereference the object returned (doubt-
	   less thinking it an ARRAY ref), they'll blow up.  This just goes to
	   show you that you should respect an object's privacy.

	       sub TIEARRAY {
		 my $class    = shift;
		 my $elemsize = shift;
		 if ( @_ || $elemsize =~ /\D/ ) {
		   croak "usage: tie ARRAY, '" . __PACKAGE__ . "', elem_size";
		 }
		 return bless {
		   ELEMSIZE => $elemsize,
		   ARRAY    => [],
		 }, $class;
	       }

       FETCH this, index
	   This method will be triggered every time an individual element the
	   tied array is accessed (read).  It takes one argument beyond its
	   self reference: the index whose value we're trying to fetch.

	       sub FETCH {
		 my $self  = shift;
		 my $index = shift;
		 return $self->{ARRAY}->[$index];
	       }

	   If a negative array index is used to read from an array, the index
	   will be translated to a positive one internally by calling FETCH-
	   SIZE before being passed to FETCH.  You may disable this feature by
	   assigning a true value to the variable $NEGATIVE_INDICES in the
	   tied array class.

	   As you may have noticed, the name of the FETCH method (et al.) is
	   the same for all accesses, even though the constructors differ in
	   names (TIESCALAR vs TIEARRAY).  While in theory you could have the
	   same class servicing several tied types, in practice this becomes
	   cumbersome, and it's easiest to keep them at simply one tie type
	   per class.

       STORE this, index, value
	   This method will be triggered every time an element in the tied
	   array is set (written).  It takes two arguments beyond its self
	   reference: the index at which we're trying to store something and
	   the value we're trying to put there.

	   In our example, "undef" is really "$self->{ELEMSIZE}" number of
	   spaces so we have a little more work to do here:

	       sub STORE {
		 my $self = shift;
		 my( $index, $value ) = @_;
		 if ( length $value > $self->{ELEMSIZE} ) {
		   croak "length of $value is greater than $self->{ELEMSIZE}";
		 }
		 # fill in the blanks
		 $self->EXTEND( $index ) if $index > $self->FETCHSIZE();
		 # right justify to keep element size for smaller elements
		 $self->{ARRAY}->[$index] = sprintf "%$self->{ELEMSIZE}s", $value;
	       }

	   Negative indexes are treated the same as with FETCH.

       FETCHSIZE this
	   Returns the total number of items in the tied array associated with
	   object this. (Equivalent to "scalar(@array)").  For example:

	       sub FETCHSIZE {
		 my $self = shift;
		 return scalar @{$self->{ARRAY}};
	       }

       STORESIZE this, count
	   Sets the total number of items in the tied array associated with
	   object this to be count. If this makes the array larger then
	   class's mapping of "undef" should be returned for new positions.
	   If the array becomes smaller then entries beyond count should be
	   deleted.

	   In our example, 'undef' is really an element containing
	   "$self->{ELEMSIZE}" number of spaces.  Observe:

	       sub STORESIZE {
		 my $self  = shift;
		 my $count = shift;
		 if ( $count > $self->FETCHSIZE() ) {
		   foreach ( $count - $self->FETCHSIZE() .. $count ) {
		     $self->STORE( $_, '' );
		   }
		 } elsif ( $count < $self->FETCHSIZE() ) {
		   foreach ( 0 .. $self->FETCHSIZE() - $count - 2 ) {
		     $self->POP();
		   }
		 }
	       }

       EXTEND this, count
	   Informative call that array is likely to grow to have count
	   entries.  Can be used to optimize allocation. This method need do
	   nothing.

	   In our example, we want to make sure there are no blank ("undef")
	   entries, so "EXTEND" will make use of "STORESIZE" to fill elements
	   as needed:

	       sub EXTEND {
		 my $self  = shift;
		 my $count = shift;
		 $self->STORESIZE( $count );
	       }

       EXISTS this, key
	   Verify that the element at index key exists in the tied array this.

	   In our example, we will determine that if an element consists of
	   "$self->{ELEMSIZE}" spaces only, it does not exist:

	       sub EXISTS {
		 my $self  = shift;
		 my $index = shift;
		 return 0 if ! defined $self->{ARRAY}->[$index] ||
			     $self->{ARRAY}->[$index] eq ' ' x $self->{ELEMSIZE};
		 return 1;
	       }

       DELETE this, key
	   Delete the element at index key from the tied array this.

	   In our example, a deleted item is "$self->{ELEMSIZE}" spaces:

	       sub DELETE {
		 my $self  = shift;
		 my $index = shift;
		 return $self->STORE( $index, '' );
	       }

       CLEAR this
	   Clear (remove, delete, ...) all values from the tied array associ-
	   ated with object this.  For example:

	       sub CLEAR {
		 my $self = shift;
		 return $self->{ARRAY} = [];
	       }

       PUSH this, LIST
	   Append elements of LIST to the array.  For example:

	       sub PUSH {
		 my $self = shift;
		 my @list = @_;
		 my $last = $self->FETCHSIZE();
		 $self->STORE( $last + $_, $list[$_] ) foreach 0 .. $#list;
		 return $self->FETCHSIZE();
	       }

       POP this
	   Remove last element of the array and return it.  For example:

	       sub POP {
		 my $self = shift;
		 return pop @{$self->{ARRAY}};
	       }

       SHIFT this
	   Remove the first element of the array (shifting other elements
	   down) and return it.  For example:

	       sub SHIFT {
		 my $self = shift;
		 return shift @{$self->{ARRAY}};
	       }

       UNSHIFT this, LIST
	   Insert LIST elements at the beginning of the array, moving existing
	   elements up to make room.  For example:

	       sub UNSHIFT {
		 my $self = shift;
		 my @list = @_;
		 my $size = scalar( @list );
		 # make room for our list
		 @{$self->{ARRAY}}[ $size .. $#{$self->{ARRAY}} + $size ]
		  = @{$self->{ARRAY}};
		 $self->STORE( $_, $list[$_] ) foreach 0 .. $#list;
	       }

       SPLICE this, offset, length, LIST
	   Perform the equivalent of "splice" on the array.

	   offset is optional and defaults to zero, negative values count back
	   from the end of the array.

	   length is optional and defaults to rest of the array.

	   LIST may be empty.

	   Returns a list of the original length elements at offset.

	   In our example, we'll use a little shortcut if there is a LIST:

	       sub SPLICE {
		 my $self   = shift;
		 my $offset = shift || 0;
		 my $length = shift || $self->FETCHSIZE() - $offset;
		 my @list   = ();
		 if ( @_ ) {
		   tie @list, __PACKAGE__, $self->{ELEMSIZE};
		   @list   = @_;
		 }
		 return splice @{$self->{ARRAY}}, $offset, $length, @list;
	       }

       UNTIE this
	   Will be called when "untie" happens. (See "The "untie" Gotcha"
	   below.)

       DESTROY this
	   This method will be triggered when the tied variable needs to be
	   destructed.	As with the scalar tie class, this is almost never
	   needed in a language that does its own garbage collection, so this
	   time we'll just leave it out.

       Tying Hashes

       Hashes were the first Perl data type to be tied (see dbmopen()).  A
       class implementing a tied hash should define the following methods:
       TIEHASH is the constructor.  FETCH and STORE access the key and value
       pairs.  EXISTS reports whether a key is present in the hash, and DELETE
       deletes one.  CLEAR empties the hash by deleting all the key and value
       pairs.  FIRSTKEY and NEXTKEY implement the keys() and each() functions
       to iterate over all the keys. SCALAR is triggered when the tied hash is
       evaluated in scalar context. UNTIE is called when "untie" happens, and
       DESTROY is called when the tied variable is garbage collected.

       If this seems like a lot, then feel free to inherit from merely the
       standard Tie::StdHash module for most of your methods, redefining only
       the interesting ones.  See Tie::Hash for details.

       Remember that Perl distinguishes between a key not existing in the
       hash, and the key existing in the hash but having a corresponding value
       of "undef".  The two possibilities can be tested with the "exists()"
       and "defined()" functions.

       Here's an example of a somewhat interesting tied hash class:  it gives
       you a hash representing a particular user's dot files.  You index into
       the hash with the name of the file (minus the dot) and you get back
       that dot file's contents.  For example:

	   use DotFiles;
	   tie %dot, 'DotFiles';
	   if ( $dot{profile} =~ /MANPATH/ ||
		$dot{login}   =~ /MANPATH/ ||
		$dot{cshrc}   =~ /MANPATH/    )
	   {
	       print "you seem to set your MANPATH\n";
	   }

       Or here's another sample of using our tied class:

	   tie %him, 'DotFiles', 'daemon';
	   foreach $f ( keys %him ) {
	       printf "daemon dot file %s is size %d\n",
		   $f, length $him{$f};
	   }

       In our tied hash DotFiles example, we use a regular hash for the object
       containing several important fields, of which only the "{LIST}" field
       will be what the user thinks of as the real hash.

       USER whose dot files this object represents

       HOME where those dot files live

       CLOBBER
	    whether we should try to change or remove those dot files

       LIST the hash of dot file names and content mappings

       Here's the start of Dotfiles.pm:

	   package DotFiles;
	   use Carp;
	   sub whowasi { (caller(1))[3] . '()' }
	   my $DEBUG = 0;
	   sub debug { $DEBUG = @_ ? shift : 1 }

       For our example, we want to be able to emit debugging info to help in
       tracing during development.  We keep also one convenience function
       around internally to help print out warnings; whowasi() returns the
       function name that calls it.

       Here are the methods for the DotFiles tied hash.

       TIEHASH classname, LIST
	   This is the constructor for the class.  That means it is expected
	   to return a blessed reference through which the new object (proba-
	   bly but not necessarily an anonymous hash) will be accessed.

	   Here's the constructor:

	       sub TIEHASH {
		   my $self = shift;
		   my $user = shift || $>;
		   my $dotdir = shift || '';
		   croak "usage: @{[&whowasi]} [USER [DOTDIR]]" if @_;
		   $user = getpwuid($user) if $user =~ /^\d+$/;
		   my $dir = (getpwnam($user))[7]
			   || croak "@{[&whowasi]}: no user $user";
		   $dir .= "/$dotdir" if $dotdir;

		   my $node = {
		       USER    => $user,
		       HOME    => $dir,
		       LIST    => {},
		       CLOBBER => 0,
		   };

		   opendir(DIR, $dir)
			   || croak "@{[&whowasi]}: can't opendir $dir: $!";
		   foreach $dot ( grep /^\./ && -f "$dir/$_", readdir(DIR)) {
		       $dot =~ s/^\.//;
		       $node->{LIST}{$dot} = undef;
		   }
		   closedir DIR;
		   return bless $node, $self;
	       }

	   It's probably worth mentioning that if you're going to filetest the
	   return values out of a readdir, you'd better prepend the directory
	   in question.  Otherwise, because we didn't chdir() there, it would
	   have been testing the wrong file.

       FETCH this, key
	   This method will be triggered every time an element in the tied
	   hash is accessed (read).  It takes one argument beyond its self
	   reference: the key whose value we're trying to fetch.

	   Here's the fetch for our DotFiles example.

	       sub FETCH {
		   carp &whowasi if $DEBUG;
		   my $self = shift;
		   my $dot = shift;
		   my $dir = $self->{HOME};
		   my $file = "$dir/.$dot";

		   unless (exists $self->{LIST}->{$dot} || -f $file) {
		       carp "@{[&whowasi]}: no $dot file" if $DEBUG;
		       return undef;
		   }

		   if (defined $self->{LIST}->{$dot}) {
		       return $self->{LIST}->{$dot};
		   } else {
		       return $self->{LIST}->{$dot} = `cat $dir/.$dot`;
		   }
	       }

	   It was easy to write by having it call the Unix cat(1) command, but
	   it would probably be more portable to open the file manually (and
	   somewhat more efficient).  Of course, because dot files are a Unixy
	   concept, we're not that concerned.

       STORE this, key, value
	   This method will be triggered every time an element in the tied
	   hash is set (written).  It takes two arguments beyond its self ref-
	   erence: the index at which we're trying to store something, and the
	   value we're trying to put there.

	   Here in our DotFiles example, we'll be careful not to let them try
	   to overwrite the file unless they've called the clobber() method on
	   the original object reference returned by tie().

	       sub STORE {
		   carp &whowasi if $DEBUG;
		   my $self = shift;
		   my $dot = shift;
		   my $value = shift;
		   my $file = $self->{HOME} . "/.$dot";
		   my $user = $self->{USER};

		   croak "@{[&whowasi]}: $file not clobberable"
		       unless $self->{CLOBBER};

		   open(F, "> $file") || croak "can't open $file: $!";
		   print F $value;
		   close(F);
	       }

	   If they wanted to clobber something, they might say:

	       $ob = tie %daemon_dots, 'daemon';
	       $ob->clobber(1);
	       $daemon_dots{signature} = "A true daemon\n";

	   Another way to lay hands on a reference to the underlying object is
	   to use the tied() function, so they might alternately have set
	   clobber using:

	       tie %daemon_dots, 'daemon';
	       tied(%daemon_dots)->clobber(1);

	   The clobber method is simply:

	       sub clobber {
		   my $self = shift;
		   $self->{CLOBBER} = @_ ? shift : 1;
	       }

       DELETE this, key
	   This method is triggered when we remove an element from the hash,
	   typically by using the delete() function.  Again, we'll be careful
	   to check whether they really want to clobber files.

	       sub DELETE   {
		   carp &whowasi if $DEBUG;

		   my $self = shift;
		   my $dot = shift;
		   my $file = $self->{HOME} . "/.$dot";
		   croak "@{[&whowasi]}: won't remove file $file"
		       unless $self->{CLOBBER};
		   delete $self->{LIST}->{$dot};
		   my $success = unlink($file);
		   carp "@{[&whowasi]}: can't unlink $file: $!" unless $success;
		   $success;
	       }

	   The value returned by DELETE becomes the return value of the call
	   to delete().  If you want to emulate the normal behavior of
	   delete(), you should return whatever FETCH would have returned for
	   this key.  In this example, we have chosen instead to return a
	   value which tells the caller whether the file was successfully
	   deleted.

       CLEAR this
	   This method is triggered when the whole hash is to be cleared, usu-
	   ally by assigning the empty list to it.

	   In our example, that would remove all the user's dot files!	It's
	   such a dangerous thing that they'll have to set CLOBBER to some-
	   thing higher than 1 to make it happen.

	       sub CLEAR    {
		   carp &whowasi if $DEBUG;
		   my $self = shift;
		   croak "@{[&whowasi]}: won't remove all dot files for $self->{USER}"
		       unless $self->{CLOBBER} > 1;
		   my $dot;
		   foreach $dot ( keys %{$self->{LIST}}) {
		       $self->DELETE($dot);
		   }
	       }

       EXISTS this, key
	   This method is triggered when the user uses the exists() function
	   on a particular hash.  In our example, we'll look at the "{LIST}"
	   hash element for this:

	       sub EXISTS   {
		   carp &whowasi if $DEBUG;
		   my $self = shift;
		   my $dot = shift;
		   return exists $self->{LIST}->{$dot};
	       }

       FIRSTKEY this
	   This method will be triggered when the user is going to iterate
	   through the hash, such as via a keys() or each() call.

	       sub FIRSTKEY {
		   carp &whowasi if $DEBUG;
		   my $self = shift;
		   my $a = keys %{$self->{LIST}};	   # reset each() iterator
		   each %{$self->{LIST}}
	       }

       NEXTKEY this, lastkey
	   This method gets triggered during a keys() or each() iteration.  It
	   has a second argument which is the last key that had been accessed.
	   This is useful if you're carrying about ordering or calling the
	   iterator from more than one sequence, or not really storing things
	   in a hash anywhere.

	   For our example, we're using a real hash so we'll do just the sim-
	   ple thing, but we'll have to go through the LIST field indirectly.

	       sub NEXTKEY  {
		   carp &whowasi if $DEBUG;
		   my $self = shift;
		   return each %{ $self->{LIST} }
	       }

       SCALAR this
	   This is called when the hash is evaluated in scalar context. In
	   order to mimic the behaviour of untied hashes, this method should
	   return a false value when the tied hash is considered empty. If
	   this method does not exist, perl will make some educated guesses
	   and return true when the hash is inside an iteration. If this isn't
	   the case, FIRSTKEY is called, and the result will be a false value
	   if FIRSTKEY returns the empty list, true otherwise.

	   However, you should not blindly rely on perl always doing the right
	   thing. Particularly, perl will mistakenly return true when you
	   clear the hash by repeatedly calling DELETE until it is empty. You
	   are therefore advised to supply your own SCALAR method when you
	   want to be absolutely sure that your hash behaves nicely in scalar
	   context.

	   In our example we can just call "scalar" on the underlying hash
	   referenced by "$self->{LIST}":

	       sub SCALAR {
		   carp &whowasi if $DEBUG;
		   my $self = shift;
		   return scalar %{ $self->{LIST} }
	       }

       UNTIE this
	   This is called when "untie" occurs.	See "The "untie" Gotcha"
	   below.

       DESTROY this
	   This method is triggered when a tied hash is about to go out of
	   scope.  You don't really need it unless you're trying to add debug-
	   ging or have auxiliary state to clean up.  Here's a very simple
	   function:

	       sub DESTROY  {
		   carp &whowasi if $DEBUG;
	       }

       Note that functions such as keys() and values() may return huge lists
       when used on large objects, like DBM files.  You may prefer to use the
       each() function to iterate over such.  Example:

	   # print out history file offsets
	   use NDBM_File;
	   tie(%HIST, 'NDBM_File', '/usr/lib/news/history', 1, 0);
	   while (($key,$val) = each %HIST) {
	       print $key, ' = ', unpack('L',$val), "\n";
	   }
	   untie(%HIST);

       Tying FileHandles

       This is partially implemented now.

       A class implementing a tied filehandle should define the following
       methods: TIEHANDLE, at least one of PRINT, PRINTF, WRITE, READLINE,
       GETC, READ, and possibly CLOSE, UNTIE and DESTROY.  The class can also
       provide: BINMODE, OPEN, EOF, FILENO, SEEK, TELL - if the corresponding
       perl operators are used on the handle.

       When STDERR is tied, its PRINT method will be called to issue warnings
       and error messages.  This feature is temporarily disabled during the
       call, which means you can use "warn()" inside PRINT without starting a
       recursive loop.	And just like "__WARN__" and "__DIE__" handlers,
       STDERR's PRINT method may be called to report parser errors, so the
       caveats mentioned under "%SIG" in perlvar apply.

       All of this is especially useful when perl is embedded in some other
       program, where output to STDOUT and STDERR may have to be redirected in
       some special way.  See nvi and the Apache module for examples.

       In our example we're going to create a shouting handle.

	   package Shout;

       TIEHANDLE classname, LIST
	   This is the constructor for the class.  That means it is expected
	   to return a blessed reference of some sort. The reference can be
	   used to hold some internal information.

	       sub TIEHANDLE { print "\n"; my $i; bless \$i, shift }

       WRITE this, LIST
	   This method will be called when the handle is written to via the
	   "syswrite" function.

	       sub WRITE {
		   $r = shift;
		   my($buf,$len,$offset) = @_;
		   print "WRITE called, \$buf=$buf, \$len=$len, \$offset=$offset";
	       }

       PRINT this, LIST
	   This method will be triggered every time the tied handle is printed
	   to with the "print()" function.  Beyond its self reference it also
	   expects the list that was passed to the print function.

	       sub PRINT { $r = shift; $$r++; print join($,,map(uc($_),@_)),$\ }

       PRINTF this, LIST
	   This method will be triggered every time the tied handle is printed
	   to with the "printf()" function.  Beyond its self reference it also
	   expects the format and list that was passed to the printf function.

	       sub PRINTF {
		   shift;
		   my $fmt = shift;
		   print sprintf($fmt, @_);
	       }

       READ this, LIST
	   This method will be called when the handle is read from via the
	   "read" or "sysread" functions.

	       sub READ {
		   my $self = shift;
		   my $bufref = \$_[0];
		   my(undef,$len,$offset) = @_;
		   print "READ called, \$buf=$bufref, \$len=$len, \$offset=$offset";
		   # add to $$bufref, set $len to number of characters read
		   $len;
	       }

       READLINE this
	   This method will be called when the handle is read from via .  The method should return undef when there is no more data.

	       sub READLINE { $r = shift; "READLINE called $$r times\n"; }

       GETC this
	   This method will be called when the "getc" function is called.

	       sub GETC { print "Don't GETC, Get Perl"; return "a"; }

       CLOSE this
	   This method will be called when the handle is closed via the
	   "close" function.

	       sub CLOSE { print "CLOSE called.\n" }

       UNTIE this
	   As with the other types of ties, this method will be called when
	   "untie" happens.  It may be appropriate to "auto CLOSE" when this
	   occurs.  See "The "untie" Gotcha" below.

       DESTROY this
	   As with the other types of ties, this method will be called when
	   the tied handle is about to be destroyed. This is useful for debug-
	   ging and possibly cleaning up.

	       sub DESTROY { print "\n" }

       Here's how to use our little example:

	   tie(*FOO,'Shout');
	   print FOO "hello\n";
	   $a = 4; $b = 6;
	   print FOO $a, " plus ", $b, " equals ", $a + $b, "\n";
	   print ;

       UNTIE this

       You can define for all tie types an UNTIE method that will be called at
       untie().  See "The "untie" Gotcha" below.

       The "untie" Gotcha

       If you intend making use of the object returned from either tie() or
       tied(), and if the tie's target class defines a destructor, there is a
       subtle gotcha you must guard against.

       As setup, consider this (admittedly rather contrived) example of a tie;
       all it does is use a file to keep a log of the values assigned to a
       scalar.

	   package Remember;

	   use strict;
	   use warnings;
	   use IO::File;

	   sub TIESCALAR {
	       my $class = shift;
	       my $filename = shift;
	       my $handle = new IO::File "> $filename"
				or die "Cannot open $filename: $!\n";

	       print $handle "The Start\n";
	       bless {FH => $handle, Value => 0}, $class;
	   }

	   sub FETCH {
	       my $self = shift;
	       return $self->{Value};
	   }

	   sub STORE {
	       my $self = shift;
	       my $value = shift;
	       my $handle = $self->{FH};
	       print $handle "$value\n";
	       $self->{Value} = $value;
	   }

	   sub DESTROY {
	       my $self = shift;
	       my $handle = $self->{FH};
	       print $handle "The End\n";
	       close $handle;
	   }

	   1;

       Here is an example that makes use of this tie:

	   use strict;
	   use Remember;

	   my $fred;
	   tie $fred, 'Remember', 'myfile.txt';
	   $fred = 1;
	   $fred = 4;
	   $fred = 5;
	   untie $fred;
	   system "cat myfile.txt";

       This is the output when it is executed:

	   The Start
	   1
	   4
	   5
	   The End

       So far so good.	Those of you who have been paying attention will have
       spotted that the tied object hasn't been used so far.  So lets add an
       extra method to the Remember class to allow comments to be included in
       the file -- say, something like this:

	   sub comment {
	       my $self = shift;
	       my $text = shift;
	       my $handle = $self->{FH};
	       print $handle $text, "\n";
	   }

       And here is the previous example modified to use the "comment" method
       (which requires the tied object):

	   use strict;
	   use Remember;

	   my ($fred, $x);
	   $x = tie $fred, 'Remember', 'myfile.txt';
	   $fred = 1;
	   $fred = 4;
	   comment $x "changing...";
	   $fred = 5;
	   untie $fred;
	   system "cat myfile.txt";

       When this code is executed there is no output.  Here's why:

       When a variable is tied, it is associated with the object which is the
       return value of the TIESCALAR, TIEARRAY, or TIEHASH function.  This
       object normally has only one reference, namely, the implicit reference
       from the tied variable.	When untie() is called, that reference is
       destroyed.  Then, as in the first example above, the object's destruc-
       tor (DESTROY) is called, which is normal for objects that have no more
       valid references; and thus the file is closed.

       In the second example, however, we have stored another reference to the
       tied object in $x.  That means that when untie() gets called there will
       still be a valid reference to the object in existence, so the destruc-
       tor is not called at that time, and thus the file is not closed.  The
       reason there is no output is because the file buffers have not been
       flushed to disk.

       Now that you know what the problem is, what can you do to avoid it?
       Prior to the introduction of the optional UNTIE method the only way was
       the good old "-w" flag. Which will spot any instances where you call
       untie() and there are still valid references to the tied object.  If
       the second script above this near the top "use warnings 'untie'" or was
       run with the "-w" flag, Perl prints this warning message:

	   untie attempted while 1 inner references still exist

       To get the script to work properly and silence the warning make sure
       there are no valid references to the tied object before untie() is
       called:

	   undef $x;
	   untie $fred;

       Now that UNTIE exists the class designer can decide which parts of the
       class functionality are really associated with "untie" and which with
       the object being destroyed. What makes sense for a given class depends
       on whether the inner references are being kept so that non-tie-related
       methods can be called on the object. But in most cases it probably
       makes sense to move the functionality that would have been in DESTROY
       to the UNTIE method.

       If the UNTIE method exists then the warning above does not occur.
       Instead the UNTIE method is passed the count of "extra" references and
       can issue its own warning if appropriate. e.g. to replicate the no
       UNTIE case this method can be used:

	   sub UNTIE
	   {
	    my ($obj,$count) = @_;
	    carp "untie attempted while $count inner references still exist" if $count;
	   }

SEE ALSO
       See DB_File or Config for some interesting tie() implementations.  A
       good starting point for many tie() implementations is with one of the
       modules Tie::Scalar, Tie::Array, Tie::Hash, or Tie::Handle.

BUGS
       The bucket usage information provided by "scalar(%hash)" is not avail-
       able.  What this means is that using %tied_hash in boolean context
       doesn't work right (currently this always tests false, regardless of
       whether the hash is empty or hash elements).

       Localizing tied arrays or hashes does not work.	After exiting the
       scope the arrays or the hashes are not restored.

       Counting the number of entries in a hash via "scalar(keys(%hash))" or
       "scalar(values(%hash)") is inefficient since it needs to iterate
       through all the entries with FIRSTKEY/NEXTKEY.

       Tied hash/array slices cause multiple FETCH/STORE pairs, there are no
       tie methods for slice operations.

       You cannot easily tie a multilevel data structure (such as a hash of
       hashes) to a dbm file.  The first problem is that all but GDBM and
       Berkeley DB have size limitations, but beyond that, you also have prob-
       lems with how references are to be represented on disk.	One experimen-
       tal module that does attempt to address this need is DBM::Deep.	Check
       your nearest CPAN site as described in perlmodlib for source code.
       Note that despite its name, DBM::Deep does not use dbm.	Another ear-
       lier attempt at solving the problem is MLDBM, which is also available
       on the CPAN, but which has some fairly serious limitations.

       Tied filehandles are still incomplete.  sysopen(), truncate(), flock(),
       fcntl(), stat() and -X can't currently be trapped.

AUTHOR
       Tom Christiansen

       TIEHANDLE by Sven Verdoolaege <skimo@dns.ufsia.ac.be> and Doug MacEach-
       ern <dougm@osf.org>

       UNTIE by Nick Ing-Simmons <nick@ing-simmons.net>

       SCALAR by Tassilo von Parseval <tassilo.von.parseval@rwth-aachen.de>

       Tying Arrays by Casey West <casey@geeknest.com>



perl v5.8.8			  2006-01-07			    PERLTIE(1)
=186258
+141
(26)