It's not really code, and I'll improve it over time, however it may be useful to those (like me) who use perl with the fantastic NEdit editor (
http://www.nedit.org).
save it as perl.tips (convert the file to UNIX end of lines!), then load it into NEdit (file->load calltips). To use the tips, select a keyword, press Ctrl+'.
If you want to load the tips automatically each time you use nedit to edit a perl file, go to Preferences->Default Settings->Language Modes, select perl, and enter the path to the file in the "Default calltips file"
update:
VERY enhanced, I detailed all standard functions, file tests and pragmas. Really a BIG tool now :)
update:
Corrected a few mistakes.
update:Corrected the language name to Perl ;)
update:Corrected some problems with pragmas.
* comment *
This reference was adapted from the web page at:
http://perldoc.perl.org/index-functions.html
send comments, bug reports, requests to Emmanuel Florac <wazoox@free.f
+r>
* version *
1.3
* language *
perl
* comment *
perl functions
abs
# abs VALUE
absolute value function.
accept
# accept NEWSOCKET,GENERICSOCKET
accept an incoming socket connect.
alarm
# alarm SECONDS
schedule a SIGALRM.
atan2
# atan2 Y,X
arctangent of Y/X in the range -PI to
PI.
bind
# bind SOCKET,NAME
binds an address to a socket.
binmode
# binmode FILEHANDLE, LAYER
# binmode FILEHANDLE
prepare binary files for I/O.
bless
# bless REF,CLASSNAME
# bless REF
create an object.
caller
# caller EXPR
returns context of the current
subroutine call.
chdir
# chdir EXPR
change the current working directory to
EXPR or $ENV{HOME} if EXPR ommited.
chmod
# chmod LIST
changes the permissions on a list of files.
The first element of the list must be
the numerical mode (usually octal).
chomp
# chomp VARIABLE
# chomp( LIST )
# chomp
remove a trailing record separator from
a string or list of strings.
chop
# chop VARIABLE
# chop( LIST )
# chop
remove the last character from a string
or a list of strings and returns the
character chopped. If variable is a
hash, chops the values, not the keys.
chown
# chown ( UID GID LIST )
change the owership on a list of files
to UID and GID. -1 as a UID/GID leaves
the value unchanged.
returns the number of changed files.
chr
# chr NUMBER
# chr
get character this number represents in
the character set.
chroot
# chroot DIRECTORY
# chroot
make directory new root for path
lookups (you must be Root for that).
close
# close FILEHANDLE
# close
close file (or pipe or socket) handle.
closedir
# closedir DIRHANDLE
close directory handle opened by
opendir.
connect
# connect SOCKET,NAME
connect to a remote socket. NAME should
be a packed address of the appropriate
type for the socket.
continue
# continue BLOCK
optional trailing block in a while or
foreach loop. Always executed.
cos
# cos EXPR
# cos
Returns the cosine of EXPR (expressed in
radians).
crypt
# crypt PLAINTEXT,SALT
one-way passwd-style encryption.
When checking an encrypted string, use
it as the salt.
dbmclose
* dbmclose HASH
[This function has been largely
superseded by the untie function.]
Breaks the binding between a DBM file
and a hash.
dbmopen
# dbmopen HASH,DBNAME,MASK
[This function has been largely
superseded by the tie function.]
create binding on a tied dbm file
(without the .dir or .pag extension). If
the database doesn't exist, it's created
with MASK access rights.
defined
# defined EXPR
# defined
test whether a value, variable, or
function is defined.
Use of defined on hashes and arrays is
deprecated.
delete
# delete EXPR
Given an expression that specifies a
hash element, array element, hash slice,
or array slice, deletes the specified
element(s) from the hash or array.
die
# die LIST
raise an exception or bail out, printing
LIST to STDERR.
do
# do BLOCK
Returns the value of the last command in
the sequence of commands indicated by
BLOCK.
# do SUBROUTINE(LIST)
A deprecated form of subroutine call.
See perlsub.
# do EXPR
Uses the value of EXPR as a filename and
executes the contents of the file as a
Perl script.
dump
# dump LABEL
# dump
create an immediate core dump.
each
# each HASH
retrieve the next key/value pair from a
hash.
endgrent
be done using group file.
endhostent
be done using hosts file.
endnetent
be done using networks file.
endprotoent
be done using protocols file.
endpwent
be done using passwd file.
endservent
be done using services file.
eof
# eof FILEHANDLE
# eof ()
# eof
test a filehandle for its end, or if
filehandle isn't open.
eval
# eval EXPR
Run EXPR as a little perl program and
returns its value.
# eval BLOCK
Execute BLOCK within the same perl
program and trap exceptions.
exec
# exec LIST
# exec PROGRAM LIST
execute a program (with optional LIST
parameters) and never returns.
exists
# exists EXPR
test whether a hash key is present (even
if undefined).
exit
# exit EXPR
# exit
Evaluates EXPR and exits immediately the
program with that value, or 0 if EXPR is
omitted.
# exp EXPR
# exp
Returns e (the natural logarithm base)
to the power of EXPR.
fcntl
# fcntl FILEHANDLE,FUNCTION,SCALAR
file control system call
fileno
# fileno FILEHANDLE
return file descriptor from filehandle.
flock
# flock FILEHANDLE,OPERATION
lock an entire file with an advisory
lock.
fork
# fork
create a new process just like this one.
format
# format
declare a picture format with use by the
write() function.
formline
# formline PICTURE,LIST
internal function used for formats.
getc
# getc FILEHANDLE
# getc
get the next character from the
filehandle (STDIN if omitted).
getgrent
get next group record.
getgrgid
get group record given group user ID.
getgrnam
get group record given group name.
gethostbyaddr
get host record given its address.
gethostbyname
get host record given name.
gethostent
get next hosts record.
getlogin
# getlogin
return who logged in at this tty.
getnetbyaddr
get network record given its address.
getnetbyname
get networks record given name.
getnetent
get next networks record.
getpeername
# getpeername SOCKET
Returns the packed sockaddr address of
other end of the SOCKET connection.
getpgrp
# getpgrp PID
get process group for PID. Use PID 0 to
get process group for the current
process.
getppid
# getppid
get parent process ID.
getpriority
# getpriority WHICH,WHO
get current nice value.
getprotobyname
get protocol record given name.
getprotobynumber
get protocol record numeric protocol.
getprotoent
get next protocols record.
getpwent
get next passwd record.
getpwnam
# getpwnam NAME
get passwd record given user login name.
getpwuid
get passwd record given user ID.
getservbyname
get services record given its name.
getservbyport
get services record given numeric port.
getservent
get next services record.
getsockname
# getsockname SOCKET
retrieve packed sockaddr address of this
end of the SOCKET connection.
getsockopt
# getsockopt SOCKET,LEVEL,OPTNAME
get socket options on a given socket
with a given LEVEL.
glob
# glob EXPR
# glob
expand filenames using wildcards.
gmtime
# gmtime EXPR
convert UNIX time into record or string
using Greenwich time.
goto
# goto LABEL
# goto EXPR
# goto &NAME
create spaghetti code.
grep
# grep BLOCK LIST
# grep EXPR,LIST
locate elements in a list test true
against a given criterion.
hex
# hex EXPR
# hex
convert a string to a hexadecimal
number.
import
# import
patch a module's namespace into your
own.
index
# index STR,SUBSTR,POSITION
# index STR,SUBSTR
find a substring within a string
starting from POSITION (or start if
omitted).
int
# int EXPR
# int
get the integer portion of a number.
ioctl
# ioctl FILEHANDLE,FUNCTION,SCALAR
system-dependent device control system
call.
join
# join EXPR,LIST
join a list into a string using EXPR
separator and returns this string.
keys
# keys HASH
Returns a list consisting of all the
keys of the named hash. (In scalar
context, returns the number of keys.)
kill
# kill SIGNAL, LIST
send a signal to a process or a list of
processes.
last
# last LABEL
# last
exit a block prematurely.
lc
# lc EXPR
# lc
return lower-case version of a string.
lcfirst
# lcfirst EXPR
# lcfirst
return a string with just the first
letter in lower case.
length
# length EXPR
# length
return the number of characters in
string EXPR.
link
# link OLDFILE,NEWFILE
Creates a new filename linked to the old
filename.
listen
# listen SOCKET,QUEUESIZE
register your socket as a server.
local
# local EXPR
create a temporary value for a global
variable (dynamic scoping).
localtime
# localtime EXPR
convert UNIX time into record or string
using local time.
lock
# lock THING
get a thread lock on a variable,
subroutine, or method.
log
# log EXPR
# log
retrieve the natural logarithm for a
number.
lstat
# lstat EXPR
# lstat
stat a symbolic link.
m
# m/REGEXP/
match a string with a regular expression
pattern.
map
# map BLOCK LIST
# map EXPR,LIST
apply a change to a list to get back a
new list with the changes.
mkdir
# mkdir FILENAME,MASK
# mkdir FILENAME
create a directory with MASK
permissions.
msgctl
# msgctl ID,CMD,ARG
SysV IPC message control operations.
msgget
# msgget KEY,FLAGS
get SysV IPC message queue.
msgrcv
# msgrcv ID,VAR,SIZE,TYPE,FLAGS
receive a SysV IPC message from a
message queue.
msgsnd
# msgsnd ID,MSG,FLAGS
send a SysV IPC message to a message
queue.
my
# my EXPR
# my TYPE EXPR
# my EXPR : ATTRS
# my TYPE EXPR : ATTRS
declare and assign a local variable
(lexical scoping).
next
# next LABEL
# next
it starts the next iteration of the
loop.
no
# no Module VERSION LIST
# no Module VERSION
# no Module LIST
# no Module
unimport some module symbols or
semantics at compile time.
oct
# oct EXPR
# oct
convert a string to an octal number.
open
# open FILEHANDLE,EXPR
# open FILEHANDLE,MODE,EXPR
# open FILEHANDLE,MODE,EXPR,LIST
# open FILEHANDLE,MODE,REFERENCE
# open FILEHANDLE
Opens the file, pipe or command whose
filename is given by EXPR, and
associates it with FILEHANDLE.
Also perl pragma to set default PerlIO
layers for input and output.
opendir
# opendir DIRHANDLE,EXPR
open a directory for processing by
readdir, telldir, seekdir, rewinddir,
and closedir.
ord
# ord EXPR
# ord
Returns a character's numeric
representation.
our
# our EXPR
# our EXPR TYPE
# our EXPR : ATTRS
# our TYPE EXPR : ATTRS
declare and assign a package variable
(lexical scoping).
pack
# pack TEMPLATE,LIST
Takes a LIST of values and converts it
into a string using the rules given by
the TEMPLATE.
package
# package NAMESPACE
# package
declare a separate global namespace.
pipe
# pipe READHANDLE,WRITEHANDLE
open a pair of connected filehandles.
pop
# pop ARRAY
# pop
remove the last element from an array
and return it
pos
# pos SCALAR
# pos
find or set the offset for the last/next
m//g search
print
# print FILEHANDLE LIST
# print LIST
# print
output a string or a list of strings to
a filehandle (or STDOUT if omitted).
printf
# printf FILEHANDLE FORMAT, LIST
# printf FORMAT, LIST
output a formatted list to a filehandle
(or STDOUT if omitted).
prototype
# prototype FUNCTION
get the prototype (if any) of a
subroutine.
push
# push ARRAY,LIST
append one or more elements to an array.
q
# q/STRING/
singly quote a string
qq
# qq/STRING/
doubly quote a string
qr
# qr/REGEXP/
Compile REGEXP pattern.
quotemeta
# quotemeta EXPR
# quotemeta
quote all non-word characters.
qw
# qw/STRING/
quote a list of words.
qx
# qx/STRING/
backquote quote a string.
rand
# rand EXPR
# rand
Returns a random fractional number
greater than or equal to 0 and less
than the value of EXPR.
read
# read FILEHANDLE,SCALAR,LENGTH,OFFSET
# read FILEHANDLE,SCALAR,LENGTH
Attempts to read LENGTH characters of
data into variable SCALAR from the
specified FILEHANDLE. Returns the number
of characters actually read, 0 at end
of file, or undef if there was an error.
readdir
# readdir DIRHANDLE
Returns the next directory entry for a
directory opened by opendir. If used in
list context, returns all the rest of
the entries in the directory.
readline
# readline EXPR
fetch a record from the filehandle
whose typeglob is contained in EXPR.
readlink
# readlink EXPR
# readlink
determine where a symbolic link is
pointing.
readpipe
# readpipe EXPR
execute EXPR as a system command and
collect standard output.
recv
# recv SOCKET,SCALAR,LENGTH,FLAGS
receive LENGTH characters of data into
variable SCALAR from the specified
SOCKET filehandle.
redo
# redo LABEL
# redo
Restarts the loop block without
evaluating the conditional again. The
continue block, if any, is not executed.
ref
# ref EXPR
# ref
Returns a non-empty string if EXPR is a
reference, the empty string otherwise.
rename
# rename OLDNAME,NEWNAME
change a filename.
require
# require VERSION
Demands a version of perl specified by
VERSION.
# require EXPR
# require
load in external functions from a
library at runtime.
reset
# reset EXPR
# reset
clear all variables of a given name.
return
# return EXPR
# return
Returns from a subroutine, eval, or do
FILE with the value given in EXPR.
reverse
# reverse LIST
In list context, returns a list value
consisting of the elements of LIST in
the opposite order. In scalar context,
concatenates the elements of LIST and
returns a string value with all
characters in the opposite order.
rewinddir
# rewinddir DIRHANDLE
Sets the current position to the
beginning of the directory for the
readdir routine on DIRHANDLE.
rindex
# rindex STR,SUBSTR,POSITION
# rindex STR,SUBSTR
right-to-left substring search, starting
from end or POSITION.
rmdir
# rmdir FILENAME
# rmdir
remove a directory.
s
# s/STRING/REGEXP/OPTIONS
substitute STRING with REGEXP.
scalar
# scalar EXPR
force a scalar context.
seek
# seek FILEHANDLE,POSITION,WHENCE
reposition file pointer for
random-access I/O. WHENCE specifies if
the new position is from start (0),
current position (1) or end of file (2).
seekdir
# seekdir DIRHANDLE,POS
reposition directory pointer. POS must
be a value returned by telldir.
select
# select FILEHANDLE
# select
Returns the currently selected
filehandle. Sets the current default
filehandle for output, if FILEHANDLE is
supplied.
semctl
# semctl ID,SEMNUM,CMD,ARG
SysV semaphore control operations.
semget
# semget KEY,NSEMS,FLAGS
get set of SysV semaphores.
semop
# semop KEY,OPSTRING
SysV semaphore operations.
send
# send SOCKET,MSG,FLAGS,TO
# send SOCKET,MSG,FLAGS
send a message over a socket.
setgrent
prepare group file for use.
sethostent
prepare hosts file for use.
setnetent
prepare networks file for use.
setpgrp
# setpgrp PID,PGRP
set the process group of a process.
setpriority
# setpriority WHICH,WHO,PRIORITY
set a process's nice value.
setprotoent
prepare protocols file for use.
setpwent
prepare passwd file for use.
setservent
prepare services file for use.
setsockopt
# setsockopt SOCKET,LEVEL,OPTNAME,OPTVAL
set some socket options.
shift
# shift ARRAY
# shift
removes the first element of an array,
and returns it.
shmctl
# shmctl ID,CMD,ARG
SysV shared memory operations.
shmget
# shmget KEY,SIZE,FLAGS
get SysV shared memory segment
identifier.
shmread
# shmread ID,VAR,POS,SIZE
read SysV shared memory.
shmwrite
write SysV shared memory.
shutdown
# shutdown SOCKET,HOW
close down just half of a socket
connection.
sin
# sin EXPR
return the sine of a number in radians.
sleep
# sleep EXPR
# sleep
block for EXPR number of seconds or
forever if EXPR omitted.
socket
# socket SOCKET,DOMAIN,TYPE,PROTOCOL
create a socket.
socketpair
# socketpair SOCKET1,SOCKET2,DOMAIN,TYPE,PROTOCOL
create a pair of sockets.
sort
# sort SUBNAME LIST
# sort BLOCK LIST
# sort LIST
sort a list of values in list context.
If SUBNAME is specified, it's a
subroutine that returns an integer less
than, equal to, or greater than 0 ,
depending on how the elements of the
list are to be ordered.
It's also a perl pragma to control sort()
behaviour.
splice
# splice ARRAY,OFFSET,LENGTH,LIST
# splice ARRAY,OFFSET,LENGTH
# splice ARRAY,OFFSET
# splice ARRAY
Remove LENGTH elements from OFFSET in an
array, and insert elements of LIST
instead.
split
# split /PATTERN/,EXPR,LIMIT
# split /PATTERN/,EXPR
# split /PATTERN/
# split
split up a string using a regexp PATTERN
delimiter or whiltespace if omitted.
sprintf
# sprintf FORMAT, LIST
Returns a formatted string.
sqrt
# sqrt EXPR
# sqrt
square root function.
srand
# srand EXPR
# srand
seed the random number generator.
stat
# stat FILEHANDLE
# stat EXPR
# stat
Returns a 13-element list giving the
status info for a file, either the file
opened via FILEHANDLE, or named by EXPR.
study
# study SCALAR
# study
optimize input data for repeated
searches.
sub
# sub NAME BLOCK
# sub NAME (PROTO) BLOCK
# sub NAME : ATTRS BLOCK
# sub NAME (PROTO) : ATTRS BLOCK
declare a subroutine, possibly
anonymously.
substr
# substr EXPR,OFFSET,LENGTH,REPLACEMENT
# substr EXPR,OFFSET,LENGTH
# substr EXPR,OFFSET
Extracts LENGTH (or all if omitted)
characters from a string starting at
OFFSET, and replaces them with
REPLACEMENT if defined.
symlink
# symlink OLDFILE,NEWFILE
create a symbolic link to a file.
syscall
# syscall NUMBER, LIST
Calls the system call specified as the
first element of the list, passing the
remaining elements as arguments to the
system call.
sysopen
# sysopen FILEHANDLE,FILENAME,MODE
# sysopen FILEHANDLE,FILENAME,MODE,PERMS
open a file, pipe, or descriptor and
associates it with FILEHANDLE.
sysread
# sysread FLHNDLE,SCALAR,LENGTH,OFFSET
# sysread FILEHANDLE,SCALAR,LENGTH
Attempts to read LENGTH bytes of data
into variable SCALAR from the specified
FILEHANDLE.
sysseek
# sysseek FILEHANDLE,POSITION,WHENCE
position I/O pointer on handle used with
sysread and syswrite.
system
# system LIST
# system PROGRAM LIST
runs a separate program by forking it,
and waits for the child process to
complete.
syswrite
# syswrite FLHANDLE,SCALAR,LENGTH,OFFSET
# syswrite FILEHANDLE,SCALAR,LENGTH
# syswrite FILEHANDLE,SCALAR
Attempts to write LENGTH bytes of data
from variable SCALAR to the specified
FILEHANDLE.
tell
# tell FILEHANDLE
# tell
Returns the current position in bytes
for FILEHANDLE.
telldir
telldir DIRHANDLE
Returns the current position of the
readdir routines on DIRHANDLE.
tie
# tie VARIABLE,CLASSNAME,LIST
This function binds a variable to a
package class that will provide the
implementation for the variable.
VARIABLE is the name of the variable to
be enchanted. CLASSNAME is the name of a
class implementing objects of correct
type. Any additional arguments are
passed to the new method of the class.
tied
# tied VARIABLE
Returns a reference to the object
underlying VARIABLE.
time
# time
return number of seconds since midnight,
Jan 1, 1970.
times
# times
Returns a four-element list giving the
user and system times, in seconds, for
this process and the children of this
process.
tr
# tr/SEARCHLIST/REPLACEMENTLIST/cds
transliterate all characters in
SEARCHLIST with corresponding characters
from REPLACEMENTLIST.
truncate
# truncate FILEHANDLE,LENGTH
# truncate EXPR,LENGTH
shorten a file to specified LENGTH.
uc
# uc EXPR
# uc
returns upper-case version of a string.
ucfirst
# ucfirst EXPR
# ucfirst
returns a string with just the first
letter in upper case.
umask
# umask EXPR
# umask
set file creation mode mask and returns
the previous value.
undef
# undef EXPR
# undef
removes a variable or function definition.
unlink
# unlink LIST
# unlink
removes one link to a file (deletes it).
unpack
# unpack TEMPLATE,EXPR
converts a binary structure into a list
of values.
unshift
# unshift ARRAY,LIST
prepends LIST elements to the beginning
of an ARRAY.
untie
# untie VARIABLE
breaks a tie binding to a variable.
use
# use Module VERSION LIST
# use Module VERSION
# use Module LIST
# use Module
# use VERSION
loads in a module at compile time, and
demands a certain VERSION of perl.
utime
# utime LIST
Changes the access and modification
times on each file of a list of files.
values
# values HASH
returns a list of the values in a hash.
vec
# vec EXPR,OFFSET,BITS
tests or sets particular bits in a
string.
wait
# wait
waits for any child process to die.
waitpid
# waitpid PID,FLAGS
wait for a particular child process to
die.
wantarray
# wantarray
Returns true if the context of the
currently executing subroutine or eval()
block is looking for a list value.
warn
# warn LIST
Produces a message on STDERR just like
die, but doesn't exit or throw an
exception.
write
# write FILEHANDLE
# write EXPR
# write
Writes a formatted record (possibly
multi-line) to the specified FILEHANDLE,
using the format associated with that
file.
-r
# -r FILE
Test if file is readable by effective
uid/gid.
-w
# -w FILE
Test if file is writable by effective
uid/gid.
-x
# -x FILE
Test if file is executable by effective
uid/gid.
-o
# -o FILE
Test if file is owned by effective uid.
-R
# -R FILE
Test if file is readable by real
uid/gid.
-W
# -W FILE
Test if file is writable by real
uid/gid.
-X
# -X FILE
Test if file is executable by real
uid/gid.
-O
# -O FILE
Test if file is owned by real uid.
-e
# -e FILE
Test if file exists.
-z
# -z FILE
Test if file has zero size (is empty).
-s
# -s FILE
Test if file has nonzero size (returns
size in bytes).
-f
# -f FILE
Test if file is a plain file.
-d
# -d FILE
Test if file is a directory.
-l
# -l FILE
Test if file is a symbolic link.
-p
# -p FILE
Test if file is a named pipe (FIFO), or
Test if filehandle is a pipe.
-S
# -S FILE
Test if file is a socket.
-b
# -b FILE
Test if file is a block special file.
-c
# -c FILE
Test if file is a character special
file.
-t
# -t FILE
Test if filehandle is opened to a tty.
-u
# -u FILE
Test if file has setuid bit set.
-g
# -g FILE
Test if file has setgid bit set.
-k
# -k FILE
Test if file has sticky bit set.
-T
# -T FILE
Test if file is an ASCII text file
(heuristic guess).
-B
# -B FILE
Test if file is a "binary" file
(opposite of -T).
-M
# -M FILE
Script start time minus file
modification time, in days.
-A
# -A FILE
Script start time minus file access
time, in days.
-C
# -C FILE
Script start time minus inode change
time (Unix, may differ for other
platforms)
y
# y/SEARCHLIST/REPLACEMENTLIST/cds
transliterate all characters in
SEARCHLIST with corresponding characters
from REPLACEMENTLIST.
* comment *
perl pragmas
attributes
get/set subroutine or variable
attributes.
attrs
set/get attributes of a subroutine
(deprecated).
autouse
postpone load of modules until a
function is used.
base
Establish IS-A relationship with base
classes at compile time.
bigint
Transparent BigInteger support for Perl.
bignum
Transparent BigNumber support for Perl.
bigrat
Transparent BigNumber/BigRational
support for Perl.
blib
Use MakeMaker's uninstalled version of a
package.
bytes
Perl pragma to force byte semantics
rather than character semantics.
charnames
define character names for \N{named}
string literal escapes.
constant
Perl pragma to declare constants.
diagnostics
produce verbose warning diagnostics.
encoding
allows you to write your script in
non-ascii or non-utf8.
fields
compile-time class fields.
filetest
Perl pragma to control the filetest
permission operators.
if
use a Perl module if a condition holds.
integer
Perl pragma to use integer arithmetic
instead of floating point.
less
perl pragma to request less of something
from the compiler.
lib
manipulate @INC at compile time.
locale
Perl pragma to use and avoid POSIX
locales for built-in operations.
ops
Perl pragma to restrict unsafe
operations when compiling.
overload
Package for overloading perl operations.
re
Perl pragma to alter regular expression
behaviour.
sigtrap
Perl pragma to enable simple signal
handling.
strict
Perl pragma to restrict unsafe
constructs.
subs
Perl pragma to predeclare sub names.
threads
Perl extension allowing use of
interpreter based threads from perl.
threads::shared
Perl extension for sharing data
structures between threads.
utf8
Perl pragma to enable/disable UTF-8 (or
UTF-EBCDIC) in source code.
vars
Perl pragma to predeclare global
variable names (obsolete).
vmsish
Perl pragma to control VMS-specific
language features.
warnings
Perl pragma to control optional
warnings.
warnings::register
warnings import function.