DOCUMENT:Q69575 17-DEC-2000 [msdos] TITLE :COPY Concatenates Files Based on Command Syntax PRODUCT :Microsoft Disk Operating System PROD/VER:MS-DOS:3.x,4.x,5.x,6.0,6.2,6.21,6.22 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft MS-DOS operating system versions 3.1, 3.2, 3.21, 3.3, 3.3a, 4.0, 4.01, 5.0, 5.0a, 6.0, 6.2, 6.21, 6.22 ------------------------------------------------------------------------------- SUMMARY ======= The MS-DOS COPY command can combine multiple files into one file. When you issue a command of the following form, COPY switches to ASCII mode and merges all source files into the target file COPY where can be of three forms: filenames with "*" or "?" (wildcard filenames), filenames separated with "+" (a specific, ordered list of files), or a combination of the two. Because the COPY command recognizes as being an absolute target, it assumes that you want to concatenate the multiple files into a single new file. This means that COPY switches to ASCII mode where end-of- file (EOF) markers are acknowledged. MORE INFORMATION ================ This behavior is sometimes confusing when you know that only one file exists that matches the source filename and you formulate a COPY command that assumes that knowledge. If you issue a command as in the following example, COPY still switches into merge mode and copies the file as if it were ASCII: COPY C:\COMM*.* A:\COMMAND.COM Although you intended to copy only COMMAND.COM from the root of drive C to the root of drive A, COPY actually tries to concatenate COMMAND.COM with some other file before it discovers that the some other file does not exist. The resulting file is shorter than the original because COPY stopped at the first 0x01A byte that it found. (In the case of COMMAND.COM, this is usually within the first ten characters, so this particular example occurs quite often). Additional query words: 6.22 3.20 3.21 3.30 3.30a 4.00 4.01 5.00 5.00a 6.00 6.20 truncate ====================================================================== Keywords : Technology : kbMSDOSSearch kbMSDOS321 kbMSDOS400 kbMSDOS320 kbMSDOS330a kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS310 kbMSDOS500 kbMSDOS330 kbMSDOS401 kbMSDOS500a Version : MS-DOS:3.x,4.x,5.x,6.0,6.2,6.21,6.22 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2000.