Libraries: Difference between revisions
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(Grossly oversimplified description of types of libraries. Someone please correct.) |
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[[Category:Encyclopedia]]'''Libraries''' are software which extend the functionality of a programming language, usually by providing an [[API]] to complete a specific task. Different languages may have their own name for libraries, such as [[Perl]] modules, or [[Java]] packages. |
[[Category:Encyclopedia]]'''Libraries''' are software which extend the functionality of a programming language, usually by providing an [[API]] to complete a specific task. Different languages may have their own name for libraries, such as [[Perl]] modules, or [[Java]] packages. They also may also be implemented in different ways. |
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=Dynamically-linked Libraries= |
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Many programming examples on Rosetta Code [[:Category:Solutions by Library|make use of libraries]]. |
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Dynamically-linked libraries are libraries that are contained in a file separate from an application's primary executable, and are loaded at [[run-time]]. This has the benefit of allowing multiple programs use of the same code both on disk and in memory, saving space. It also allows a program to load additional, optional or interchangeable portions of itself into memory at runtime. |
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On Windows, these files are known as, naturally enough, as '''Dynamically-Linked Libraries''', from which their file extension '''DLL''' is derived. |
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On UNIX-derived systems, these files are known as '''Shared Objects'', from which their file extension '''so''' is derived. |
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==Implicit vs Explicit linking== |
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In [[implicit linking]], an operating system sees that a program will require the use of a library, and loads it automatically. In [[explicit linking]], the running program asks the operating system to load the library. |
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=Statically-linked Libraries= |
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Statically-linked libraries are combined with a program's code at [[compile-time]], their code and the program's code combined to form a single executable. |
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=See also= |
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* [[Category:Solutions by Library]] |
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Revision as of 03:56, 31 January 2008
Libraries are software which extend the functionality of a programming language, usually by providing an API to complete a specific task. Different languages may have their own name for libraries, such as Perl modules, or Java packages. They also may also be implemented in different ways.
Dynamically-linked Libraries
Dynamically-linked libraries are libraries that are contained in a file separate from an application's primary executable, and are loaded at run-time. This has the benefit of allowing multiple programs use of the same code both on disk and in memory, saving space. It also allows a program to load additional, optional or interchangeable portions of itself into memory at runtime.
On Windows, these files are known as, naturally enough, as Dynamically-Linked Libraries, from which their file extension DLL is derived.
On UNIX-derived systems, these files are known as Shared Objects, from which their file extension so' is derived.
Implicit vs Explicit linking
In implicit linking, an operating system sees that a program will require the use of a library, and loads it automatically. In explicit linking, the running program asks the operating system to load the library.
Statically-linked Libraries
Statically-linked libraries are combined with a program's code at compile-time, their code and the program's code combined to form a single executable.