diskcomp(CMD) 19 June 1992 diskcomp(CMD) Name diskcomp - compare the contents of two floppy disks Syntax diskcomp [drive1: [drive2:]] [/1] [/8] Description This command performs a track-by-track comparison. diskcomp determines the number of sides and sectors per track to compare based on the format of the first disk you specify. Parameters drive1: Specifies the drive containing one of the floppy disks. drive2: Specifies the drive containing the other floppy disk. Switches /1 Compares only the first sides of the disks, even if the disks are double-sided and the drives can read double-sided disks. /8 Compares only the first 8 sectors per track, even if the disks contain 9 or 15 sectors per track. Notes Invalid drive for diskcomp The diskcomp command works only with floppy disks. You cannot use diskcomp with a hard disk. If you specify a hard disk drive for drive1 or drive2, diskcomp displays the following error message: Invalid drive specification Specified drive does not exist or is non-removable Diskcomp messages If all tracks on the two disks being compared are the same, diskcomp dis- plays the following message: Compare OK If the tracks are not the same, diskcomp displays a message similar to the following: Compare error on side 1, track 2 When diskcomp completes the comparison, it displays the following mes- sage: Compare another diskette (Y/N)? If you press Y, diskcomp prompts you to insert disks for the next com- parison. If you press N, diskcomp stops the comparison. diskcomp ignores a disk's volume number when it makes the comparison. Omitting drive parameters If you omit the drive2 parameter, diskcomp uses the current drive for drive2. If you omit both drive parameters, diskcomp uses the current drive for both. If the current drive is the same as drive1, diskcomp prompts you to swap disks as necessary. Using one drive for the comparison If you specify the same floppy disk drive for drive1 and drive2, diskcomp does a comparison by using one drive and prompts you to insert the disks as necessary. You might have to swap the disks more than once, depending on the capacity of the disks and the amount of available memory. Comparing different types of disks diskcomp cannot compare a single-sided disk with a double-sided disk, nor a high-density disk with a double-density disk. If the disk in drive1 is not of the same type as the disk in drive2, diskcomp displays the follow- ing message: Drive types or diskette types not compatible Using diskcomp with networks and redirected drives diskcomp does not work on a network drive or on a drive created or affected by an assign, join, or subst command. If you attempt to use diskcomp with a drive of any of these types, diskcomp displays an error message. Comparing an original disk with a copy When you use diskcomp with a disk that you made with the copy command, diskcomp may display a message similar to the following: Compare error on side 0, track 0 This type of error can occur even if the files on the disks are identi- cal. Although the copy command duplicates information, it does not neces- sarily place it in the same location on the destination disk. For more information about comparing individual files on two disks, see the fc(CMD) command. Diskcomp exit codes The following list shows each exit code and a brief description of its meaning: 0 The disks are the same. 1 Differences were found. 2 The user pressed CtrlC to stop the process. 3 A hard error occurred. 4 An initialization error occurred. You can use the errorlevel parameter on the if command line in a batch program to process exit codes returned by diskcomp. For an example of a batch program that processes exit codes, see the following ``Examples'' section. Examples If your system has only one floppy disk drive, drive A, and you want to compare two disks, type the following command: diskcomp a: a: diskcomp prompts you to insert each disk, as required. Following is an example of a batch program that uses the errorlevel parameter on the if command line to process a diskcomp exit code: rem CHECKOUT.BAT compares the disks in drive A and B echo off diskcomp a: b: if errorlevel 4 goto ini_error if errorlevel 3 goto hard_error if errorlevel 2 goto break if errorlevel 1 goto no_compare if errorlevel 0 goto compare_ok :ini_error echo ERROR: Insufficient memory or command invalid goto exit :hard_error echo ERROR: An irrecoverable error occurred goto exit :break echo You just pressed CTRL+C to stop the comparison goto exit :no_compare echo Disks are not the same goto exit :compare_ok echo The comparison was successful; the disks are the same goto exit :exit Related commands For information about comparing two files, see the comp(CMD) and fc(CMD) commands.