In digital file management, copying is a file operation that creates a new file which has the same content as an existing file. Computer operating systems include file copying methods to users; operating systems with graphical user interfaces (GUIs) often providing copy-and-paste or drag-and-drop methods of file copying. Operating systems may have specialized file-copying APIs are usually able to tell the server to perform the copying locally, without sending file contents over the network, thus greatly improving performance.
File copying is the creation of a new copy file which has the same content as an existing file.
Shadowedit
There are several different technologies that use the term shadowing, but the intent of shadowing within these technologies is to provide an exact copy (or mirror of a set) of data. For shadowing to be effective, the shadow needs to exist in a separate physical location than the original data. Depending on the reasons behind the shadow operation, this location may be as close as the BIOS chip to the RAM modules, a second harddrive in the same chassis, or as far away as the other side of the globe.
Internally, however, while some systems have specialized application programming interfaces (APIs) for copying files (like CopyFile and CopyFileEx in Windows API), others (like Unix and DOS) fall back to simply reading the contents of the old file and writing it to the new file.
This makes little difference with local files (those on the computer's hard drive), but provides an interesting situation when both the source and target files are located on a remote file server. Operating systems with specialized file copying APIs are usually able to tell the server to perform the copying locally, without sending file contents over the network, thus greatly improving performance. Those systems that have no comparable APIs, however, have to read the file contents over the network, and then send them back again, over the network. Sometimes, remote file copying is performed with a specialized command, like "NCOPY" in DOS clients for Novell NetWare. The COPY command in some versions of DR-DOS since 1992,[1] has built-in support for this. An even more complicated situation arises when one needs to copy files between two remote servers. The simple way is to read data from one server, and then to write the data to the second server.
^"Caldera OpenDOS Machine Readable Source Kit (M.R.S) 7.01". Caldera, Inc. 1997-05-01. from the original on 2021-08-07. Retrieved 2022-01-02. (NB. Actually implemented since DR DOS "Panther" on 1992-06-22, see COMCPY.C/DOSIF.ASM in the COMMAND.COM sources of OpenDOS 7.01.)
Further readingedit
N-level file shadowing and recovery in a shared file system, United States Patent 5043876
Method of file shadowing among peer systems, United States Patent 5276871
file, copying, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, december, 20. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources File copying news newspapers books scholar JSTOR December 2009 Learn how and when to remove this template message In digital file management copying is a file operation that creates a new file which has the same content as an existing file Computer operating systems include file copying methods to users operating systems with graphical user interfaces GUIs often providing copy and paste or drag and drop methods of file copying Operating systems may have specialized file copying APIs are usually able to tell the server to perform the copying locally without sending file contents over the network thus greatly improving performance Contents 1 Description 1 1 Shadow 2 Use 3 Implementation 4 See also 5 References 6 Further reading 7 External linksDescription editFile copying is the creation of a new copy file which has the same content as an existing file Shadow edit There are several different technologies that use the term shadowing but the intent of shadowing within these technologies is to provide an exact copy or mirror of a set of data For shadowing to be effective the shadow needs to exist in a separate physical location than the original data Depending on the reasons behind the shadow operation this location may be as close as the BIOS chip to the RAM modules a second harddrive in the same chassis or as far away as the other side of the globe Use editAll computer operating systems include file copying provisions in the user interface like the command cp in Unix and COPY in DOS operating systems with a graphical user interface or GUI usually provide copy and paste or drag and drop methods of file copying File manager applications too provide an easy way of copying files Implementation editInternally however while some systems have specialized application programming interfaces APIs for copying files like CopyFile and CopyFileEx in Windows API others like Unix and DOS fall back to simply reading the contents of the old file and writing it to the new file This makes little difference with local files those on the computer s hard drive but provides an interesting situation when both the source and target files are located on a remote file server Operating systems with specialized file copying APIs are usually able to tell the server to perform the copying locally without sending file contents over the network thus greatly improving performance Those systems that have no comparable APIs however have to read the file contents over the network and then send them back again over the network Sometimes remote file copying is performed with a specialized command like NCOPY in DOS clients for Novell NetWare The COPY command in some versions of DR DOS since 1992 1 has built in support for this An even more complicated situation arises when one needs to copy files between two remote servers The simple way is to read data from one server and then to write the data to the second server See also editComputer file Moving methods Core dump Soft copy Hard copy List of file copying software ln Unix NTFS junction point Zero copyReferences edit Caldera OpenDOS Machine Readable Source Kit M R S 7 01 Caldera Inc 1997 05 01 Archived from the original on 2021 08 07 Retrieved 2022 01 02 1 NB Actually implemented since DR DOS Panther on 1992 06 22 see COMCPY C DOSIF ASM in the COMMAND COM sources of OpenDOS 7 01 Further reading editN level file shadowing and recovery in a shared file system United States Patent 5043876 Method of file shadowing among peer systems United States Patent 5276871 Database Shadow FilesExternal links editInstructions on how to shadow files for Emacs Retrieved from https en wikipedia org w index php title File copying amp oldid 1211288847 NCOPY, wikipedia, wiki, book, books, library,
