C/C++ Users Group Library 1996 July

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FILES - A Small File and Directory Manipulation Utility for DOS by Philip J. Erdelsky PLAIN VANILLA CORPORATION CompuServe 75746,3411 InterNet 75746.3411@compuserve.com January 15, 1993 PUBLIC DOMAIN -- NO RESTRICTIONS ON USE 1. Introduction --------------- The FILES utility is a small file and directory manipulation utility for DOS (versions 2.00 and later). It was written mainly to test RDCF 2.0 and duplicates a number of DOS internal and external commands, but it adds enough functions to DOS to be useful in itself. Here is what you can do with the FILES utility that you cannot do with DOS commands alone: (1) You can see hidden, system and deleted files and volume labels in directory listings. (You can see hidden and system files, but not deleted files, with DOS 5.0.) (2) You can change the date and time of a file, directory or volume label. (3) You can sort a directory. (4) You can restore a deleted file, if the file is not fragmented and has not been overwritten. (5) You can move a file or subdirectory from one directory to another without copying its data. (6) You can recover remnants of deleted files in the empty data clusters. (7) You can wipe out remnants of deleted files in empty data clusters so they cannot be recovered later. Some of these things can't be done even by special programs that issue DOS calls. The FILES utility can do them only because it goes around the DOS file system and accesses the disk on a sector-by-sector basis. The FILES utility works with diskettes and hard disk partitions smaller than 32 megabytes. It will not work with larger partitions, such as those used by DOS 4.00 and later versions of DOS, and it will not work with LAN drives. IMPORTANT: The FILES utility does not recognize any current drive or subdirectory. You will have to type an explicit drive specification for every file, and, for a file not in the root directory, a complete directory path. Contrary to the usual DOS practice, the directory path must NOT begin with a backslash. Sorry about that. The FILES utility and its source code are in the public domain, but the RDCF 2.0 file package is copyrighted. If you want to make changes to the FILES utility for your own use, you will have to obtain RDCF 2.0. You may make copies for your own use, but commercial use of RDCF 2.0 requires permission. You will also need a third package called the Reentrant Cache System 1.1, but that is also in the public domain. The current version of the FILES utility treats drives other than A: and B: as read-only. You can change that if you know what you're doing. 2. Bringing up the FILES Utility -------------------------------- The FILES utility resides in the file FILES.EXE. Copy this file from the distribution diskette, or download it from a BBS. Make sure the file FILES.EXE is in the current directory, or in a directory made accessible by the DOS PATH command, and type FILES in response to the DOS prompt. The FILES utility will then display its prompt: FILES> Enter FILES commands just as you would enter DOS commands, using the backspace key to make corrections. If you have installed a DOS command line editor, it will probably work with the FILES utility because the utility uses the same DOS system call (number 10) as the DOS command line interpreter. It is presumed that you are reasonably conversant with DOS commands. You can execute FILES commands from a file by simply redirecting the file to the FILES utility as its standard input; e.g., FILES <file Be sure to end the file with an EXIT command, or you'll have to reboot to regain control of your computer! If you use this technique, remember that the command file is being read by DOS, not by the FILES utility. Do not include FILES commands that write to the drive on which the command file resides. The FILES utility and DOS will not cooperate. If you can't remember the FILES commands, just type HELP in response to the FILES> prompt. Here is what you'll see: COPY source destination DATE file month-day-year hour:min:sec DEL file DIR directory DIRSORT directory EXIT HELP MD directory MCOPY files directory MOVE source destination RECOVER file REN old new TYPE file UNDEL file VOLUME name WIPE drive 2.1. COPY - Copy a File ----------------------- The FILES command COPY source destination copies one file to another, just the way DOS does. However, you cannot copy multiple files, and you must supply complete file specifications. For example, to copy the file FOO.C from drive A: to the subdirectory \PROG on drive B:, you must type COPY A:FOO.C B:PROG\FOO.C For file copying, you'll probably prefer to use DOS. 2.2. DATE - Change the Date and Time of a File, Directory or Volume ------------------------------------------------------------------- The FILES command DATE file month-day-year hour:min:sec changes the date and time of a file or subdirectory. The date and time are expressed in numerical form, and a 24-hour clock is used. To change the date and time of the file A:FOO.C to September 15, 1992, 3:15 PM, type DATE A:FOO.C 9-15-92 15:13:00 If the file specifications represent a subdirectory, its date and time will be changed. That's something DOS won't do! If you use a drive specification only, the date and time of the volume label will be changed. 2.3 DEL - Delete a File, Directory or Volume -------------------------------------------- The FILES command DEL file deletes the specified file. If the file specifications represent a subdirectory, it deletes the subdirectory (provided it is empty). Hence it does the work of both the DOS DEL and RD commands. If you use a drive specification only, the volume label will be deleted. 2.4. DIR - Directory Listing ---------------------------- The FILES command DIR directory lists the contents of the specified directory, including volume labels, hidden and system files, subdirectories and deleted volume labels, files and subdirectories. If you use a drive specification only, contents of the root directory will be displayed. To pause the display, type Ctrl-S; to abort the display, type Ctrl-C. 2.5. DIRSORT - Sort a Directory ------------------------------- The FILES command DIRSORT directory mode sorts the entries in the specified directory in the specified manner. The mode may be any ONE of the following: mode manner of sort ---- ----------------------------------------------------------------- E sort by extension, then among files that have the same extension, sort by name D sort by date and time (earlier files first) N sort by name, then among files that have the same name, sort by extension S sort by size (smallest files first) The letter R may be appended to any of these modes to sort in the opposite order. For example, SR sorts the files by size, but it puts the largest files first. If you omit the mode, N is presumed. Actually, before the FILES utility sorts the directory entries, it first divides them into five groups and arranges them in the following order: (1) The two system files at the beginning of the root directory and the two special files "." and ".." at the beginning of a subdirectory are always left where they are. (2) The volume label, if any, is put next. (3) The subdirectory entries, if any, are sorted and put next. (4) The file entries are sorted and put next. (5) The entries for deleted files, volume labels and subdirectories, if any, are sorted and put last. Within each category, if two entries are identical according to the sorting criterion, their relative position is left unchanged. If you supply only a drive specification, the root directory will be sorted. The sorting algorithm is fairly unsophisticated, so sorting a long subdirectory may take quite some time. Please be patient. 2.6. EXIT - Return to DOS ------------------------- The following FILES command returns control to DOS: EXIT If you redirect commands from a file to the FILES utility, be sure to end it with an EXIT command. Otherwise, the utility will hang up at the end of the file and you'll have to reboot to regain control of your computer. 2.7. HELP - Display a List of FILES Commands -------------------------------------------- The following FILES command displays a list of FILES commands: HELP 2.8. MD - Make Directory ------------------------ The FILES command MD directory creates the specified directory, just like the corresponding DOS command. 2.9. MOVE - Move a File or Subdirectory --------------------------------------- The FILES command MOVE source destination moves the source file to the destination file. Since it is not possible to move a file from one drive to another with this command, the destination file specifications must NOT contain a drive specification. For example, to move the file FOO.C from the root directory to the subdirectory PROG on drive B:, type MOVE B:FOO.C PROG\FOO.C The effect of this command is the same (in almost all cases) as the following two commands, but it is much more efficient because the data is not copied: COPY source destination DEL source (Slight differences occur when the disk is nearly full. The COPY-DEL sequence may fail for lack of disk space but MOVE will succeed.) You can rename a file as you move it merely by giving it a different name in the new directory. You could also use this command to rename a file without moving it, but it would be less efficient than the REN command and might fail for lack of directory space when then REN command wouldn't. If the source file specifications represent a subdirectory, it and all of the files and subdirectories in it will be moved. That's something that DOS won't do, and it can be quite handy. However, be sure not to corrupt the file system by moving a directory into itself or one of its own subdirectories. The FILES utility won't protect you from such folly. 2.10. RECOVER - Recover Deleted File Remnants in Empty Clusters --------------------------------------------------------------- The FILES command RECOVER file creates the specified file as a new file, gathers all the empty data clusters on drive and links them together as the new file contents. The new file will then contain all the data from deleted files and subdirectories that has not been reused by other files or subdirectories. If you want to use a text editor or word processor on the new file to find the desired information, you will probably have to copy the file to another disk or a hard drive that has room for the temporary and backup files that most text editors and word processors require. For obvious reasons, there won't be any room on the same disk! The new file must not be the same as an existing file. It may reside in a subdirectory, but the FILES utility will not lengthen the subdirectory to accommodate it, since that would destroy some of the information that you want to recover. 2.11. REN - Rename a File ------------------------- The FILES command REN old new renames a file, without moving it to another directory or drive. The new file specifications may include a name and extension only. For example, the following command changes the file A:PROG\FOO.C into A:PROG\BAH.C: REN A:PROG\FOO.C BAH.C 2.12. TYPE - Display a File --------------------------- The FILES command TYPE file displays the contents of a file. To pause the display, type Ctrl-S; to abort the display, type Ctrl-C. 2.13. UNDEL - Undelete a File ----------------------------- The FILES command UNDEL file attempts to restore a deleted file. The FILES utility will tell you whether the file is unrecoverable, partly recoverable or fully recoverable. Even if the file appears to have been fully recovered, there is no guarantee that the original file contents have been restored. For example, if another file has been written over the original contents and then deleted, there is no way that the FILES utility can determine that the original contents have been changed. Even if this has not happened, the FILES utility may not know exactly where to look for the contents. It just does the best it can. 2.14. VOLUME - Add or Change Volume Label ----------------------------------------- The FILES command VOLUME drive: displays the volume label for the specified drive, or tells you that the drive has no volume label. The FILES command VOLUME drive: label changes the volume label on the specified drive to the specified text, or adds a new volume label with the specified text. DOS file and directory names and extensions are case-insensitive, but the same is NOT true of volume labels. They can contain small letters, spaces and some special characters. Command syntax will prevent you from embedding a space in a volume label, even though DOS might permit it on a disk. 2.15. WIPE - Wipe Empty Data Clusters ------------------------------------- The FILES command WIPE d: writes nonsense into all unused data clusters on the specified drive, so any remnants of deleted files on the drive cannot be recovered by either the UNDEL or the RECOVER command. CAUTION: If the drive uses data clusters consisting of more than one sector, there may be some remnants of deleted files in the last clusters of files that are not long enough to occupy all sectors of their last clusters. These little snippets of information cannot be recovered by the FILES utility, but they can be recovered by more sophisticated utilities.