Home>Language reference> Perl functions A-Z
Perl functions A-Z
Perl functions A-Z|Perl functions by category|The 'perlfunc' manpage
A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y| Z
A
AUTOLOAD
abs- absolute value function
accept- accept an incoming socket connect
alarm- schedule a SIGALRM
and
atan2- arctangent of Y/X in the range -PI to PI
B
BEGIN
bind- binds an address to a socket
binmode- prepare binary files for I/O
bless- create an object
break- break out of a "given" block
C
CHECK
caller- get context of the current subroutine call
chdir- change your current working directory
chmod- changes the permissions on a list of files
chomp- remove a trailing record separator from a string
chop- remove the last character from a string
chown- change the owership on a list of files
chr- get character this number represents
chroot- make directory new root for path lookups
close- close file (or pipe or socket) handle
closedir- close directory handle
cmp
connect- connect to a remote socket
continue- optional trailing block in a while or foreach
cos- cosine function
crypt- one-way passwd-style encryption
D
DESTROY
DATA
dbmclose- breaks binding on a tied dbm file
dbmopen- create binding on a tied dbm file
default
defined- test whether a value, variable, or function is defined
delete- deletes a value from a hash
die- raise an exception or bail out
do- turn a BLOCK into a TERM
dump- create an immediate core dump
E
END
END
each- retrieve the next key/value pair from a hash
else
elseif
elsif
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- test a filehandle for its end
eq
eval- catch exceptions or compile and run code
evalbytes
exec- abandon this program to run another
exists- test whether a hash key is present
exit- terminate this program
exp- raise Ito a power
F
FILE
fc
fcntl- file control system call
fileno- return file descriptor from filehandle
flock- lock an entire file with an advisory lock
for
foreach
fork- create a new process just like this one
format- declare a picture format with use by the write() function
formline- internal function used for formats
G
ge
getc- get the next character from the filehandle
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- 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- find the other end of a socket connection
getpgrp- get process group
getppid- get parent process ID
getpriority- 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- 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- retrieve the sockaddr for a given socket
getsockopt- get socket options on a given socket
given
glob- expand filenames using wildcards
gmtime- convert UNIX time into record or string using Greenwich time
goto- create spaghetti code
grep- locate elements in a list test true against a given criterion
gt
H
hex- convert a string to a hexadecimal number
I
INIT
if
import- patch a module's namespace into your own
index- find a substring within a string
int- get the integer portion of a number
ioctl- system-dependent device control system call
J
join- join a list into a string using a separator
K
keys- retrieve list of indices from a hash
kill- send a signal to a process or process group
L
LINE
last- exit a block prematurely
lc- return lower-case version of a string
lcfirst- return a string with just the next letter in lower case
le
length- return the number of bytes in a string
link- create a hard link in the filesytem
listen- register your socket as a server
local- create a temporary value for a global variable (dynamic scoping)
localtime- convert UNIX time into record or string using local time
lock- get a thread lock on a variable, subroutine, or method
log- retrieve the natural logarithm for a number
lstat- stat a symbolic link
lt
M
m- match a string with a regular expression pattern
map- apply a change to a list to get back a new list with the changes
mkdir- create a directory
msgctl- SysV IPC message control operations
msgget- get SysV IPC message queue
msgrcv- receive a SysV IPC message from a message queue
msgsnd- send a SysV IPC message to a message queue
my- declare and assign a local variable (lexical scoping)
N
ne
next- iterate a block prematurely
no- unimport some module symbols or semantics at compile time
not
O
oct- convert a string to an octal number
open- open a file, pipe, or descriptor
opendir- open a directory
or
ord- find a character's numeric representation
our- declare and assign a package variable (lexical scoping)
P
PACKAGE
pack- convert a list into a binary representation
package- declare a separate global namespace
pipe- open a pair of connected filehandles
pop- remove the last element from an array and return it
pos- find or set the offset for the last/next m//g search
print- output a list to a filehandle
printf- output a formatted list to a filehandle
prototype- get the prototype (if any) of a subroutine
push- append one or more elements to an array
Q
q- singly quote a string
qq- doubly quote a string
qr- Compile pattern
quotemeta- quote regular expression magic characters
qw- quote a list of words
qx- backquote quote a string
R
rand- retrieve the next pseudorandom number
read- fixed-length buffered input from a filehandle
readdir- get a directory from a directory handle
readline- fetch a record from a file
readlink- determine where a symbolic link is pointing
readpipe- execute a system command and collect standard output
recv- receive a message over a Socket
redo- start this loop iteration over again
ref- find out the type of thing being referenced
rename- change a filename
require- load in external functions from a library at runtime
reset- clear all variables of a given name
return- get out of a function early
reverse- flip a string or a list
rewinddir- reset directory handle
rindex- right-to-left substring search
rmdir- remove a directory
S
SUB
s- replace a pattern with a string
say- print with newline
scalar- force a scalar context
seek- reposition file pointer for random-access I/O
seekdir- reposition directory pointer
select- reset default output or do I/O multiplexing
semctl- SysV semaphore control operations
semget- get set of SysV semaphores
semop- SysV semaphore operations
send- 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- set the process group of a process
setpriority- 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- set some socket options
shift- remove the first element of an array, and return it
shmctl- SysV shared memory operations
shmget- get SysV shared memory segment identifier
shmread- read SysV shared memory
shmwrite- write SysV shared memory
shutdown- close down just half of a socket connection
sin- return the sine of a number
sleep- block for some number of seconds
socket- create a socket
socketpair- create a pair of sockets
sort- sort a list of values
splice- add or remove elements anywhere in an array
split- split up a string using a regexp delimiter
sprintf- formatted print into a string
sqrt- square root function
srand- seed the random number generator
stat- get a file's status information
state- declare and assign a state variable (persistent lexical scoping)
study- optimize input data for repeated searches
sub- declare a subroutine, possibly anonymously
substr- get or alter a portion of a stirng
symlink- create a symbolic link to a file
syscall- execute an arbitrary system call
sysopen- open a file, pipe, or descriptor
sysread- fixed-length unbuffered input from a filehandle
sysseek- position I/O pointer on handle used with sysread and syswrite
system- run a separate program
syswrite- fixed-length unbuffered output to a filehandle
T
tell- get current seekpointer on a filehandle
telldir- get current seekpointer on a directory handle
tie- bind a variable to an object class
tied- get a reference to the object underlying a tied variable
time- return number of seconds since 1970
times- return elapsed time for self and child processes
tr- transliterate a string
truncate- shorten a file
U
UNITCHECK
uc- return upper-case version of a string
ucfirst- return a string with just the next letter in upper case
umask- set file creation mode mask
undef- remove a variable or function definition
unless
unlink- remove one link to a file
unpack- convert binary structure into normal perl variables
unshift- prepend more elements to the beginning of a list
untie- break a tie binding to a variable
until
use- load in a module at compile time
utime- set a file's last access and modify times
V
values- return a list of the values in a hash
vec- test or set particular bits in a string
W
wait- wait for any child process to die
waitpid- wait for a particular child process to die
wantarray- get void vs scalar vs list context of current subroutine call
warn- print debugging info
when
while
write- print a picture record
X
-X- a file test (-r, -x, etc)
x
xor
Y
y- transliterate a string