Any input line that does not begin with '/' will be sent directly to the foreground world, if there is one. A line starting with more than one '/' will be sent to the forground socket after having the first '/' removed. (Exception: lines may be caught with a SEND hook before being sent; see "hooks").
Any input line beginning with a single '/' is a TF command, which will be interpreted as described in "evaluation".
Input lines of the form "^old^new" will cause TF to search
backward in the input history for a
line containing "old", replace that text with "new", and execute the
modified command. See: history.
Many special functions, such as backspace, can be performed by special keys or sequences of keys. See "dokey" for a complete list. You can also define your own commands and bind them to key sequences. See bind.
Normally, user input does not undergo the
expansion that
macro bodies undergo. The
/eval command can be used to
expand text before executing it.
If the %{sub} flag is on
(it is off by default), user input undergoes
macro body
expansion without the
%{sub} flag. The
%{sub} flag also applies
to text generated by "^old^new" history commands.
See: history,
/sub,
variables
Control characters may be input literally. A literal control character will be displayed in the input window in printable form in bold reverse. Note that since most control keys are also parts of the default keybindings, it will usually be necessary to type ^V (/dokey LNEXT) to avoid invoking the keybinding.
International characters may be input if your locale is set to a locale that supports them and your system supports locales. Any input character that is not valid in your locale and has the high bit set (normally generated by holding the "meta" key) will be translated to ESC plus that character with the high bit stripped (assuming %meta_esc is on). This allows M-x and ^[x to invoke the same ^[x keybinding. See locale, %meta_esc, %istrip.
If standard input is not a terminal, visual mode will not be allowed, and tf will continue to operate even after EOF is read, until /quit or something else terminates it.