Problem with accidental removal File deletion

the common problem deleting files accidental removal of information later proves important. 1 way deal files regularly. erroneously deleted files may found in archives.

another technique used not delete files instantly, move them temporary directory contents can deleted @ will. how recycle bin or trash can works. microsoft windows , apple s mac os x, linux distributions, employ strategy.

in ms-dos, 1 can use undelete command. in ms-dos deleted files not deleted, marked deleted—so undeleted during time, until disk blocks used taken other files. how data recovery programs work, scanning files have been marked deleted. space freed per byte, rather per file, can cause data recovered incompletely. defragging drive may prevent undeletion, blocks used deleted file might overwritten since marked empty .

another precautionary measure mark important files read-only. many operating systems warn user trying delete such files. file system permissions exist, users lack necessary permissions able delete own files, preventing erasure of other people s work or critical system files.

under unix-like operating systems, in order delete file, 1 must have write permission parent directory of file.