Less hotkeys not working, printing keycodes instead performing action

Question

When I try something like

php -i | less

Less is not responding to hotkeys, but prints them like pressing "q" results in statusline

:q

PageDown

:^[[6~

Pressing ENTER like "executes" the keycode and less perfoems the action.

Piping trivial small stuff work however...

OS: Fedora 14

Dennis Williamson · Answer 1 · 2011-03-15 00:35:39Z

up vote 0 down vote accepted

php -i is doing something weird with stdin. Try this:

php -i </dev/null | less

answered Mar 15 '11 at 0:35

	Great suggestion, thanks. – SnakeSurgeon Mar 15 '11 at 6:32
	Actually, it's `less` that does the "something weird". It changes to non-canonical mode input processing. Of course `php` may well be doing something as well, but this is simply a specific case of the more general don't have two programs simultaneously interacting with the terminal that employ different terminal input modes and expect things to work. – JdeBP Mar 17 '11 at 20:29
	@JdeBP: `less` may very well be doing something weird, but this is from `strace php -i` without `less`: `ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0` – Dennis Williamson Mar 17 '11 at 21:00
	Setting canonical mode input processing (`icanon`) is not "something weird". Canonical mode is the norm. Hence its name. – JdeBP Mar 18 '11 at 13:44
	@JdeBP: Well, I don't know what's hidden behind the `...` and perhaps the clue lies elsewhere. But why is `php -i` opening stdin at all? It does this same odd behavior with `more` (which is not a symlink or alias on my system), but, interestingly, not `pg` or (inconsistently) `most`. PHP also does this with `php -r 'for ($i = 1; $i <= 100; $i++) { print "$i\n"; }' \| less`. AWK, Perl, Python, etc., don't exhibit this weirdness. Conclusion: PHP is broken. – Dennis Williamson Mar 18 '11 at 14:42

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