Perl — page 2 of 5

Perl terms

101. currently selected output channel The last "filehandle" that was designated with select(FILEHANDLE); "STDOUT", if no filehandle has been selected.
102. CV (1) Carrier Vehicle. (2) USN Aircraft Carrier. (3) Curriculum Vitae.
103. dangling statement A bare, single "statement", without any braces, hanging off an if or while conditional. C allows them. Perl doesn't.
104. data structure How your various pieces of data relate to each other and what shape they make when you put them all together, as in a rectangular table or a…
105. data type The type of information that one field can store, for example, text, rich text, numbers, keywords, and time.
106. datagram A packet of information passed between two communicating processes across a network.
107. DBM Stands for "Data Base Management" routines, a set of routines that emulate an "associative array" using disk files.
108. declaration a document in which an applicant for patent declares, under penalty of fine or imprisonment, or both (18 USC 1001), that (1) he or she is the original or…
109. Decrement A directed funding level reduction for an acquisition program.
110. Default Default occurs when a debtor is unable to meet the legal obligation of debt repayment, one form of which is the failure to promptly pay interest or…
111. defined 1. Fixed conditions of medium, environment and protocol for growth. 2. Precisely known and stated elements of a tissue culture medium.
112. delimiter A "character" or "string" that sets bounds to an arbitrarily-sized textual object, not to be confused with a "separator" or "terminator".
113. deprecated modules and features Deprecated modules and features are those which were part of a stable release, but later found to be subtly flawed, and which should be avoided.
114. dereference A fancy computer science term meaning "to follow a "reference" to what it points to".
115. derived class A "class" that defines some of its methods in terms of a more generic class, called a "base class".
116. Descriptor See "file descriptor".
117. destroy To deallocate the memory of a "referent" (first triggering its DESTROY method, if it has one).
118. destructor A special "method" that is called when an "object" is thinking about destroying itself.
119. device A whiz-bang hardware gizmo (like a disk or tape drive or a modem or a joystick or a mouse) attached to your computer, that the "operating system" tries to…
120. directive A "pod" directive. See perlpod.
121. Directory A simulated file folder or container used to organize files and directories in a hierarchical or tree-like structure.
122. directory handle A name that represents a particular instance of opening a directory to read it, until you close it. See the opendir function.
123. dispatch To send something to its correct destination. Often used metaphorically to indicate a transfer of programmatic control to a destination selected…
124. Distribution The sale of securities. Also refers to a sum payable to shareholders representing their share of profits.
125. dweomer An enchantment, illusion, phantasm, or jugglery. Said when Perl's magical "dwimmer" effects don't do what you expect, but rather seem to be the product of…
126. dwimmer DWIM is an acronym for "Do What I Mean", the principle that something should just do what you want it to do without an undue amount of fuss.
127. dynamic scoping Dynamic scoping works over a dynamic scope, making variables visible throughout the rest of the "block" in which they are first used and in any…
128. eclectic Derived from many sources. Some would say too many.
129. element (EH-leh-ment) A basic part of a whole. In chemistry, refers to a simple substance that cannot be broken down into smaller parts or changed into another…
130. embedding When something is contained in something else, particularly when that might be considered surprising: "I've embedded a complete Perl interpreter in my…
131. empty subclass test The notion that an empty "derived class" should behave exactly like its "base class".
132. en passant When you change a "value" as it is being copied. [From French, "in passing", as in the exotic pawn-capturing maneuver in chess.]
133. encapsulation Any method packaging an enzyme or bacterium and maintaining its normal functions. Used to immobilize cells in a bioreactor.
134. endian See "little-endian" and "big-endian".
135. Environment All the natural and living things around us. The earth, air, weather, plants, and animals all make up our environment.
136. environment variable A mechanism by which some high-level agent such as a user can pass its preferences down to its future offspring (child processes, grandchild processes…
137. EOF End of File. Sometimes used metaphorically as the terminating string of a "here document".
138. errno The error number returned by a "syscall" when it fails. Perl refers to the error by the name $! (or $OS_ERROR if you use the English module).
139. error Error The difference between a measured value of a quantity and its true value. Different types of errors are inherent to observations.
140. escape sequence See "metasymbol".
141. exception the temporary suspension of some essential element of a policy, procedure, or requirement caused by circumstances that are expected to return to normal at…
142. exception handling The way a program responds to an error. The exception handling mechanism in Perl is the eval operator.
143. exec To throw away the current "process"'s program and replace it with another without exiting the process or relinquishing any resources held (apart from the…
144. executable file A "file" that is specially marked to tell the "operating system" that it's okay to run this file as a program. Usually shortened to "executable".
145. Execute To complete; to sign; to carry out according to its terms.
146. execute bit The special mark that tells the operating system it can run this program. There are actually three execute bits under Unix, and which bit gets used…
147. exit status See "status".
148. export Data extracted or taken out of one environment or application usually in a prescribed format, and usually for import into another environment or…
149. expression A combination of operands and operators that produces a resulting value. Expressions have a resulting type, that affects the context in which they may be…
150. extension The short single-stranded stretch of nucleotides remaining on a double-stranded DNA molecule, following treatment with a restriction endonuclease which…
151. false In Perl, any value that would look like "" or "0" if evaluated in a string context.
152. FAQ Frequently Asked Questions
153. fatal error A fatal error occurs in the SAX parser when a document is not well formed or otherwise cannot be processed. See also error, warning.
154. field Field A region of space at each point of which a given physical or mathematical quantity has some definite value.
155. FIFO First In, First Out. See also "LIFO". Also, a nickname for a "named pipe".
156. file To place a paper in the official custody of the clerk of court/court administrator to enter into the files or records of a case.
157. file descriptor The little number the "operating system" uses to keep track of which opened "file" you're talking about.
158. file test operator A built-in unary operator that you use to determine whether something is "true" about a file, such as -o $filename to test whether you're the owner of the…
159. fileglob A "wildcard" match on filenames. See the glob function.
160. filehandle An identifier (not necessarily related to the real name of a file) that represents a particular instance of opening a file until you close it.
161. Filename The name of a file, excluding root drive and directory path information. Different operating systems may impose different restrictions on filenames, for…
162. filesystem A set of directories and files residing on a partition of the disk. Sometimes known as a "partition".
163. filter A criterion you specify to limit the results when you list or describe your Amazon EC2 resources.
164. flag See affinity tag.
165. floating point A method of storing numbers in "scientific notation", such that the precision of the number is independent of its magnitude (the decimal point "floats").
166. flush a hand of five cards all of the same suit, irrespective of value
167. FMTEYEWTK Far More Than Everything You Ever Wanted To Know. An exhaustive treatise on one narrow topic, something of a super-"FAQ". See Tom for far more.
168. fork Terms used to refer to a Unix fork, supported MJS scheduler mechanism.
169. formal arguments The generic names by which a "subroutine" knows its arguments. In many languages, formal arguments are always given individual names, but in Perl, the…
170. Format The internal structure of a file, which defines the way it is stored and used. Specific applications may define unique formats for their data (i.e.
171. freely available Means you don't have to pay money to get it, but the copyright on it may still belong to someone else (like Larry).
172. freely redistributable Means you're not in legal trouble if you give a bootleg copy of it to your friends and we find out about it.
173. freeware Historically, any software that you give away, particularly if you make the source code available as well. Now often called open source software.
174. function A built-in formula that performs a specialized calculation automatically.
175. funny character Someone like Larry, or one of his peculiar friends. Also refers to the strange prefixes that Perl requires as noun markers on its variables.
176. garbage collection The automatic detection and freeing of memory that is no longer in use. The Java runtime system performs garbage collection so that programmers never…
177. GID Group ID--in Unix, the numeric group ID that the "operating system" uses to identify you and members of your "group".
178. glob Strictly, the shell's * character, which will match a "glob" of characters when you're trying to generate a list of filenames.
179. global Something you can see from anywhere, usually used of variables and subroutines that are visible everywhere in your program.
180. global destruction The "garbage collection" of globals (and the running of any associated object destructors) that takes place when a Perl "interpreter" is being shut down.
181. glue language A language such as Perl that is good at hooking things together that weren't intended to be hooked together.
182. Granularity The size of the pieces you're dealing with, mentally speaking.
183. greedy A "subpattern" whose "quantifier" wants to match as many things as possible.
184. grep Originally from the old Unix editor command for "Globally search for a Regular Expression and Print it", now used in the general sense of any kind of…
185. group (also referred to as a Technology Center or TC) - a unit of several Group Art Units in the mechanical, electrical, chemical or design area, managed by one…
186. GV An internal "glob value" typedef, holding a "typeglob". The "GV" type is a subclass of "SV".
187. Hacker Someone who breaks into computer systems in order to steal, change or destroy information.
188. Handler A "subroutine" or "method" that is called by Perl when your program needs to respond to some internal event, such as a "signal", or an encounter with an…
189. hard reference A "scalar" "value" containing the actual address of a "referent", such that the referent's "reference" count accounts for it.
190. Hash A mathematical algorithm that represents a unique value for a given set of data, similar to a digital fingerprint.
191. hash table A data structure used internally by Perl for implementing associative arrays (hashes) efficiently. See also "bucket".
192. header file A file containing certain required definitions that you must include "ahead" of the rest of your program to do certain obscure operations.
193. here document So called because of a similar construct in shells that pretends that the lines following the "command" are a separate "file" to be fed to the command, up…
194. hexadecimal A number system with a base of 16. The digits are 0-9 and A-F, where F equals the decimal value of 15.
195. home directory The directory you are put into when you log in. On a Unix system, the name is often placed into $ENV{HOME} or $ENV{LOGDIR} by login, but you can also find…
196. host In a network, the central computer which controls the remote computers and holds the central databases.
197. hubris Excessive pride, the sort of thing Zeus zaps you for. Also the quality that makes you write (and maintain) programs that other people won't want to say…
198. HV have
199. I/O Input/Output .
200. identifier A programmer-defined name for a variable, method, class or interface.