The GNU Readline library is a programming tool that provides a consistent user interface for recalling lines of previously typed input and performing editing tasks on input lines. paul@freefall.cdrom.com There was a bug with tcsh: when readline attempt to get tty modes from background, it got no-echo editing tcsh mode. Workaround for this implemented via TIOCGWINSZ/TIOCSWINSZ with same winsize structure: it does nothing expect polling process from background. Look tcsh_hack.readme for details. Here is megred version with readline comes from gdb4.11 and with readline 2.0 comes from bash ache@astral.msk.su