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In digitalfile management,copying is afile operation that creates a newfile which has the same content as an existing file. Computeroperating systems include file copying methods to users; operating systems withgraphical user interfaces (GUIs) often providingcopy-and-paste ordrag-and-drop methods of file copying. Operating systems may have specialized file-copyingAPIs 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 newcopyfile which has the same content as an existing file.
There are several different technologies that use the termshadowing, but the intent of shadowing within these technologies is to provide an exact copy (ormirror 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 thereasons 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.
All computeroperating systems include file copying provisions in the user interface, like the command, "cp" inUnix and "COPY" inDOS; operating systems with agraphical user interface, orGUI, usually providecopy-and-paste ordrag-and-drop methods of file copying. File manager applications, too, provide an easy way of copying files.
Internally, however, while some systems have specializedapplication programming interfaces (APIs) for copying files (like CopyFile and CopyFileEx inWindows 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 remotefile 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 forNovell NetWare. TheCOPY command in some versions ofDR-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.