In the text version of IDA, you can use the following keys:
Enter starts a new line Ctrl-Enter finishes the input Esc cancels the input F1 gives some help
Shift-<arrow> Select
Ctrl-L Search Again Shift-Ins Paste
Ctrl-O Indent Mode Shift-Del Cut
Ctrl-T Delete Word Ctrl-Ins Copy
Ctrl-U Undo Ctrl-Del Clear
Ctrl-Y Delete Line Ctrl-K B Start Select
Ctrl-Left Word Left Ctrl-K H Hide Select
Ctrl-Right Word Right
Ctrl-PgUp Text Start Ctrl-Q A Replace
Ctrl-PgDn Text End Ctrl-Q F Search
Ctrl-Q H Delete Line Start
Ctrl-Q Y Delete Line End
Input containing only whitespaces is equal to an empty input.
Do not forget that you can also use the clipboard.