Thursday, November 17, 2011

The copy command under DOS

Syntax:

COPY [/Y|-Y] [/A][/B] [d:][path]filename [/A][/B] [d:][path][filename] [/V]
or
COPY [/Y|-Y] [/A][/B] [d:][path]filename+[d:][path]filename[...] [d:][path][filename] [/V]

Purpose: Copies or appends files. Files can be copied with the same name or with a new name.

Discussion

COPY is usually used to copy one or more files from one location to another. However, COPY can also be used to create new files. By copying from the keyboard console (COPY CON:) to the screen, files can be created and then saved to disk.

The first filename you enter is referred to as the source file. The second filename you enter is referred to as the target file. If errors are encountered during the copying process, the COPY program will display error messages using these names.

Unlike the BACKUP command, copied files are stored in the same format they are found in. The copied files can be used just as you would use the original (whether the copied file is a data file or a program).

COPY can also be used to transfer data between any of the system devices. Files may also be combined during the copy process. 
NOTE:
Files can be copied to the same directory only if they are copied with a new name. If you copy a file to a different directory without specifying a new name, the file will be copied with the same name. If you attempt to copy a file to the same directory without providing a new name, DOS will cancel the copy and display the message

File cannot be copied onto itself

The COPY command was also discussed in Chapter 1, Introduction, in the downloadable book DOS the Easy Way.

Options

/Y - Causes COPY to replace existing files without providing a confirmation prompt. By default, if you specify an existing file as the destination file, COPY will provide a confirmation prompt. (In previous versions of DOS, existing files were simply overwritten.)

/-Y - Displays a confirmation prompt before copying over existing files.

/A - Used to copy ASCII files. Applies to the filename preceding it and to all following filenames. Files will be copied until an end-of-file mark is encountered in the file being copied. If an end-of-file mark is encountered in the file, the rest of the file is not copied. DOS will append an end-of-file mark at the end of the copied file.

/B - Used to copy binary files. Applies to the filename preceding it and to all following filenames. Copied files will be read by size (according to the number of bytes indicated in the file`s directory listing). An end-of-file mark is not placed at the end of the copied file.

/V - Checks after the copy to assure that a file was copied correctly. If the copy cannot be verified, the program will display an error message. Using this option will result in a slower copying process.

Examples

The first filename you enter is the source file; the second file is the target file. To copy the file TEST.DOC from the current directory to drive B (with the same name), enter

copy test.doc b:

To copy the file TEST.DOC to the current directory with the new name, TEST2, enter

copy test.doc test2

To copy and combine (concatenate) the files TEST1.DOC and TEST2.DOC to a new file, TEST3, enter

copy test1.doc+test2.doc b:test3

You can also combine files by using wildcard characters (? and *). To copy all files with a .DOC filename extension on drive C to a new file ALLDOCS on drive B, enter

copy c:*.doc b:alldocs

Other, more complicated, combinations are also possible while copying. For example, to combine all files with a .TXT filename extension with all files that have the same filename and a .DOC extension, copying the newly combined file to a new file on drive B with an .ADD extension, enter

copy *.txt+*.doc b:*.add

In this case, the file TEST.TXT will be combined with the file TEST.DOC resulting in a combined file with the filename TEST.ADD.