Broken backspace handling in top

top takes the character code for backspace from ncurses, which retrieves it from the terminfo database. In reality, some terminals (notably xterm) provide a runtime configuration option to select which character code is produced by the Backspace key. terminfo has no means to account for this. In addition, GNU Screen and other terminal multiplexers replace the content of TERM, such that even a correct value has no chance of being retrieved. Note that GNU Screen's entry has kbs = ^H, which rarely matches the behavior of backspace on GNU/Linux systems. The result is that working with top inside screen tends to be frustrating: one has to type Ctrl-H (or Ctrl-Backspace in xterm) in order to erase a character.

The preferred solution is to use the erase character configured on the output terminal: this is modifiable at runtime and is likely to reflect the terminal's actual configuration, only failing where utilities operating in cooked mode likewise fail, following the principle of least surprise. Some terminals actually allow to query the current setting using the DECRQM control sequence, but it doesn't seem worth the trouble.