CONTENTS

• Perl Functions by Category
• Alphabetical Listing of Perl Functions

Full documentation of builtin functions: perlfunc

#Perl Functions by Category

Here are Perl's functions (including things that look like functions, like some keywords and named operators) arranged by category. Some functions appear in more than one place. Any warnings, including those produced by keywords, are described in perldiag and warnings.

#Functions for SCALARs or strings

chomp, chop, chr, crypt, fc, hex, index, lc, lcfirst, length, oct, ord, pack, q//, qq//, reverse, rindex, sprintf, substr, tr///, uc, ucfirst, y///

fc is available only if the "fc" feature is enabled or if it is prefixed with CORE::. The "fc" feature is enabled automatically with a use v5.16 (or higher) declaration in the current scope.

#Regular expressions and pattern matching

m//, pos, qr//, quotemeta, s///, split, study

#Numeric functions

abs, atan2, cos, exp, hex, int, log, oct, rand, sin, sqrt, srand

#Functions for real @ARRAYs

each, keys, pop, push, shift, splice, unshift, values

#Functions for list data

all, any, grep, join, map, qw//, reverse, sort, unpack

#Functions for real %HASHes

delete, each, exists, keys, values

#Input and output functions

binmode, close, closedir, dbmclose, dbmopen, die, eof, fileno, flock, format, getc, print, printf, read, readdir, readline, rewinddir, say, seek, seekdir, select, syscall, sysread, sysseek, syswrite, tell, telldir, truncate, warn, write

say is available only if the "say" feature is enabled or if it is prefixed with CORE::. The "say" feature is enabled automatically with a use v5.10 (or higher) declaration in the current scope.

#Functions for fixed-length data or records

pack, read, syscall, sysread, sysseek, syswrite, unpack, vec

#Functions for filehandles, files, or directories

-X, chdir, chmod, chown, chroot, fcntl, glob, ioctl, link, lstat, mkdir, open, opendir, readlink, rename, rmdir, select, stat, symlink, sysopen, umask, unlink, utime

#Keywords related to the control flow of your Perl program

break, caller, continue, die, do, dump, eval, evalbytes, exit, __FILE__, goto, last, __LINE__, method, next, __PACKAGE__, redo, return, sub, __SUB__, wantarray

break is available only if you enable the experimental "switch" feature or use the CORE:: prefix. The "switch" feature also enables the default, given and when statements, which are documented in "Switch Statements" in perlsyn. The "switch" feature is enabled automatically with a use v5.10 (or higher) declaration in the current scope. In Perl v5.14 and earlier, continue required the "switch" feature, like the other keywords.

evalbytes is only available with the "evalbytes" feature (see feature) or if prefixed with CORE::. __SUB__ is only available with the "current_sub" feature or if prefixed with CORE::. Both the "evalbytes" and "current_sub" features are enabled automatically with a use v5.16 (or higher) declaration in the current scope.

#Keywords related to scoping

caller, class, field, import, local, my, our, package, state, use

state is available only if the "state" feature is enabled or if it is prefixed with CORE::. The "state" feature is enabled automatically with a use v5.10 (or higher) declaration in the current scope.

#Miscellaneous functions

defined, formline, lock, prototype, reset, scalar, undef

#Functions for processes and process groups

alarm, exec, fork, getpgrp, getppid, getpriority, kill, pipe, qx//, readpipe, setpgrp, setpriority, sleep, system, times, wait, waitpid

#Keywords related to Perl modules

do, import, no, package, require, use

#Keywords related to classes and object-orientation

bless, class, __CLASS__, dbmclose, dbmopen, field, method, package, ref, tie, tied, untie, use

#Low-level socket functions

accept, bind, connect, getpeername, getsockname, getsockopt, listen, recv, send, setsockopt, shutdown, socket, socketpair

#System V interprocess communication functions

msgctl, msgget, msgrcv, msgsnd, semctl, semget, semop, shmctl, shmget, shmread, shmwrite

#Fetching user and group info

endgrent, endhostent, endnetent, endpwent, getgrent, getgrgid, getgrnam, getlogin, getpwent, getpwnam, getpwuid, setgrent, setpwent

#Fetching network info

endprotoent, endservent, gethostbyaddr, gethostbyname, gethostent, getnetbyaddr, getnetbyname, getnetent, getprotobyname, getprotobynumber, getprotoent, getservbyname, getservbyport, getservent, sethostent, setnetent, setprotoent, setservent

#Time-related functions

gmtime, localtime, time, times

#Non-function keywords

ADJUST, and, AUTOLOAD, BEGIN, catch, CHECK, cmp, CORE, __DATA__, default, defer, DESTROY, else, elseif, elsif, END, __END__, eq, finally, for, foreach, ge, given, gt, if, INIT, isa, le, lt, ne, not, or, try, UNITCHECK, unless, until, when, while, x, xor

#Alphabetical Listing of Perl Functions

• -X - a file test (-r, -x, etc)

• __CLASS__ - the class name of the current instance.

• __FILE__ - the name of the current source file

• __LINE__ - the current source line number

• __PACKAGE__ - the current package

• __SUB__ - the current subroutine, or undef if not in a subroutine

• abs - absolute value function

• accept - accept an incoming socket connect

• alarm - schedule a SIGALRM

• all - test if every value in a list satisfies the given condition

• any - test if at least one value in a list satisfies the given condition

• atan2 - arctangent of Y/X in the range -PI to PI

• 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

• 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 ownership on a list of files

• chr - get character this number represents

• chroot - make directory new root for path lookups

• class - declare a separate global namespace that is an object class

• close - close file (or pipe or socket) handle

• closedir - close directory handle

• connect - connect to a remote socket

• continue - optional trailing block in a while or foreach

• cos - cosine function

• crypt - one-way passwd-style encryption

• dbmclose - breaks binding on a tied dbm file

• dbmopen - create binding on a tied dbm file

• 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

• each - retrieve the next key/value pair from a hash or index/value from an array

• 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

• eval - catch exceptions or compile and run code

• evalbytes - similar to string eval, but intend to parse a bytestream

• exec - abandon this program to run another

• exists - test whether a hash key is present

• exit - terminate this program

• exp - raise e to a power

• fc - return casefolded version of a string

• fcntl - file control system call

• field - declare a field variable of the current class

• fileno - return file descriptor from filehandle

• flock - lock an entire file with an advisory lock

• 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

• 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

• 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

• hex - convert a hexadecimal string to a number

• 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

• join - join a list into a string using a separator

• keys - retrieve list of indices from a hash or array

• kill - send a signal to a process or process group

• 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

• length - return the number of characters in a string

• link - create a hard link in the filesystem

• 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

• 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

• method - declare a method of a class

• 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)

• next - iterate a block prematurely

• no - unimport some module symbols or semantics at compile time

• oct - convert a string to an octal number

• open - open a file, pipe, or descriptor

• opendir - open a directory

• ord - find a character's code point

• our - declare and assign a package variable (lexical scoping)

• 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/STRING/ - singly quote a string

• qq/STRING/ - doubly quote a string

• qr/STRING/ - compile pattern

• quotemeta - quote regular expression magic characters

• qw/STRING/ - quote a list of words

• qx/STRING/ - backquote quote a string

• 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/// - replace a pattern with a string

• say - output a list to a filehandle, appending a 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 persistent lexical variable

• study - no-op, formerly optimized input data for repeated searches

• sub - declare a subroutine, possibly anonymously

• substr - get or alter a portion of a string

• 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

• 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

• uc - return upper-case version of a string

• ucfirst - return a string with the first letter in upper case

• umask - set file creation mode mask

• undef - remove a variable or function definition

• 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

• use - enable Perl language features and declare required version

• utime - set a file's last access and modify times

• values - return a list of the values in a hash or array

• vec - test or set particular bits in a string

• 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

• write - print a picture record

• y/// - transliterate a string

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