chroot - make directory new root for path lookups

chroot This function works like the system call by the same name: it makes the named directory the new ... directory) immediately after a chroot, otherwise the current working directory may be outside of the new

sysseek - position I/O pointer on handle used with sysread and syswrite

The values for WHENCE are 0 to set the new position to POSITION; 1 to set it to the current position ... " function: use Fcntl 'SEEK_CUR'; sub systell { sysseek($_[0], 0, SEEK_CUR) } Returns the new

link OLDFILE,NEWFILE Creates a new filename linked to the old filename.

field - declare a field variable of the current class

field VARNAME Declares a new field variable within the current class.

method - declare a method of a class

method NAME BLOCK method NAME : ATTRS BLOCK Creates a new named method in the scope of the class that

write - print a picture record

the page is advanced by writing a form feed and a special top-of-page format is used to format the new ... The number of lines remaining on the current page is in variable $-, which can be set to 0 to force a new

symlink OLDFILE,NEWFILE Creates a new filename symbolically linked to the old filename.

join - join a list into a string using a separator

separate strings of LIST into a single string with fields separated by the value of EXPR, and returns that new

select - reset default output or do I/O multiplexing

If FILEHANDLE is supplied, sets the new current default filehandle for output. ... ; # This goes to $new_handle: print "ok 1\n"; ...

opendir - open a directory

an undefined scalar variable (or array or hash element), the variable is assigned a reference to a new

unshift - prepend more elements to the beginning of a list

@colors = ("red"); unshift(@colors, ("blue", "green")); # ("blue", "green", "red") Returns the new

sort - sort a list of values

$1 : undef ); push @caps, fc($_); } my @new = @old[ sort { ... = sort function_with_signature @old; # guarantee stability use sort 'stable'; my @new =

state - declare and assign a persistent lexical variable

Redeclaring a variable in the same scope or statement will "shadow" the previous declaration, creating a new

my - declare and assign a local variable (lexical scoping)

Redeclaring a variable in the same scope or statement will "shadow" the previous declaration, creating a new

reverse - flip a string or a list

Also, this has to unwind one hash and build a whole new one, which may take some time on a large hash

die - raise an exception or bail out

\n" unless chdir '/usr/spool/news'; chdir '/usr/spool/news' or die "Can't cd to spool: $! ... Here's an example: use Scalar::Util "blessed"; eval { ... ; die Some::Module::Exception->new

crypt - one-way passwd-style encryption

This ensures crypt will hash the new string with the same salt as the digest. ... When choosing a new salt create a random two character string whose characters come from the set [./0

dump - create an immediate core dump

When the new binary is executed it will begin by executing a goto LABEL (with all the restrictions that

fork - create a new process just like this one

fork Does a fork(2) system call to create a new process running the same program at the same point

open - open a file, pipe, or descriptor

In the child process, the filehandle isn't opened--I/O happens from/to the new STDOUT/STDIN. ... New code should favor the three-argument form of open over this older form.

dbmopen - create binding on a tied dbm file

Example: # print out history file offsets dbmopen(%HIST,'/usr/lib/news/history',0666); while

seek - reposition file pointer for random-access I/O

The values for WHENCE are 0 to set the new position in bytes to POSITION; 1 to set it to the current

alarm - schedule a SIGALRM

previous timer, and an argument of 0 may be supplied to cancel the previous timer without starting a new

require - load in external functions from a library at runtime

Here is a typical code layout for an INC hook: # In package Foo; sub new { ... } ... my (undef, @parameters) = @$arrayref; ... } or: push @INC, [ HookObj->new(), $x, $y

tie - bind a variable to an object class

: # print out history file offsets use NDBM_File; tie(my %HIST, 'NDBM_File', '/usr/lib/news

sysopen - open a file, pipe, or descriptor

We know that these values do not work under OS/390; you probably don't want to use them in new code.

flock - lock an entire file with an advisory lock

emulation, by passing the switch -Ud_flock to the Configure program when you configure and build a new

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

Unlike my and state, which both declare new (lexical) variables, our only creates an alias to an existing

caller - get context of the current subroutine call

$hasargs is true if a new instance of @_ was set up for the frame.

each - retrieve the next key/value pair from a hash

A new underlying array or hash is created each time so each will always start iterating from scratch,

binmode - prepare binary files for I/O

All variants of Unix, Mac OS (old and new), and Stream_LF files on VMS use a single character to end

use - enable Perl language features and declare required version

However, this may be subject to change in a future release of Perl, so new code should not rely on this