repaircd

repaircd is a command-line utility designed to help users recover data from damaged or corrupted CD-ROM, CD-R, and CD-RW media. It works by reading sectors from the optical disc sequentially and attempting to reconstruct data even if some sectors are unreadable. This process can be useful when standard file system tools fail to access files due to physical damage or read errors on the disc.

The utility's primary function is to create an image file of the damaged disc, attempting to fill in gaps with null data or alternative values where read errors occur. Users can then mount this image file or use other data recovery tools on it to extract as much data as possible. repaircd typically requires the user to specify the input device (the CD-ROM drive) and the output image file path. It may also offer options to control the read speed or the number of retries for problematic sectors, aiming to maximize the chances of successful data recovery.

The effectiveness of repaircd depends heavily on the extent and nature of the damage to the optical media. Minor scuffs or surface defects may be overcome, but severe physical damage such as deep scratches or delamination can render data recovery impossible. It is often considered a last resort for retrieving data from media that cannot be read by conventional means.