delete

1. operating system (Or "erase") To make a file

inaccessible.

Usually this operation only deletes information from the

tables the file system uses to locate named files; the

file's contents still exist on disk and can sometimes be

recovered by scanning the whole disk for strings which are

known to have been in the file. Files created subsequently on

the same disk are quite likely to reuse the same blocks and

thus overwrite the deleted file's data permanently.

2. character The control character with ASCII code 127.

Usually entering this character from the keyboard deletes the

last character typed from the input buffer. Sadly there is

great confusion between operating systems and keyboard

manufacturers as to whether this function should be assigned

to the delete or backspace key/character.

The choice of code 127 (binary 1111111) is not arbitrary but

dates back to the use of paper tape for input. The delete

key rewound the tape by one character and punched out all

seven holes, thus obliterating whatever character was there

before. The tape reading software ignored any delete

characters in the input.

(1996-12-01)