Our use of the terminfo database in /usr/share/terminfo/$TERM is both
1. a way for users to configure app behavior in their terminal (by
setting TERM, copying around and modifying terminfo files)
2. a way for terminal emulator developers to advertise support for
backwards-incompatible features that are not otherwise easily observable.
To 1: this is not ideal (it's very easy to break things). There's not many
things that realistically need configuration; let's use shell variables
instead.
To 2: in practice, feature-probing via terminfo is often wrong. There's not
many backwards-incompatible features that need this; for the ones that do
we can still use terminfo capabilities but query the terminal via XTGETTCAP
directly, skipping the file (which may not exist on the same system as
the terminal).
---
Get rid of terminfo. If anyone finds a $TERM where we need different behavior,
we can hardcode that into fish.
* Allow to override this with `fish_features=no-ignore-terminfo fish`
Not sure if we should document this, since it's supposed to be removed soon,
and if someone needs this (which we don't expect), we'd like to know.
* This is supported on a best-effort basis; it doesn't match the previous
behavior exactly. For simplicity of implementation, it will not change
the fact that we now:
* use parm_left_cursor (CSI Ps D) instead of cursor_left (CSI D) if
terminfo claims the former is supported
* no longer support eat_newline_glitch, which seems no longer present
on today's ConEmu and ConHost
* Tested as described in https://github.com/fish-shell/fish-shell/pull/11345#discussion_r2030121580
* add `man fish-terminal-compatibility` to state our assumptions.
This could help terminal emulator developers.
* assume `parm_up_cursor` is supported if the terminal supports XTGETTCAP
* Extract all control sequences to src/terminal_command.rs.
* Remove the "\x1b(B" prefix from EXIT_ATTRIBUTE_MODE. I doubt it's really
needed.
* assume it's generally okay to output 256 colors
Things have improved since commit 3669805627 (Improve compatibility with
0-16 color terminals., 2016-07-21).
Apparently almost every actively developed terminal supports it, including
Terminal.app and GNU screen.
* That is, we default `fish_term256` to true and keep it only as a way to
opt out of the the full 256 palette (e.g. switching to the 16-color
palette).
* `TERM=xterm-16color` has the same opt-out effect.
* `TERM` is generally ignored but add back basic compatiblity by turning
off color for "ansi-m", "linux-m" and "xterm-mono"; these are probably
not set accidentally.
* Since `TERM` is (mostly) ignored, we don't need the magic "xterm" in
tests. Unset it instead.
* Note that our pexpect tests used a dumb terminal because:
1. it makes fish do a full redraw of the commandline everytime, making it
easier to write assertions.
2. it disables all control sequences for colors, etc, which we usually
don't want to test explicitly.
I don't think TERM=dumb has any other use, so it would be better
to print escape sequences unconditionally, and strip them in
the test driver (leaving this for later, since it's a bit more involved).
Closes#11344Closes#11345
e697add5b5 (Feature flag to prevent executing off buffered keys, 2025-01-02)
breaks my expectations/habits, and it breaks Midnight Commander.
Additionally, I'm not aware of any case where it actually adds security.
We generally assume that terminal echoback sequences do not contain
control characters except for well-known escape sequences.
This backs out commit e697add5b5.
See #10987, #10991
If I run "sleep 3", type a command and hit enter, then there is no
obvious way to cancel or edit the imminent command other than ctrl-c
but that also cancels sleep, and doesn't allow editing. (ctrl-z sort
of works, but also doesn't allow editing).
Let's try to limit ourselves to inserting the buffered command
(translating enter to a newline), and only execute once the user
actually presses enter after the previous command is done.
Hide it behind a new feature flag for now.
By making things less scary, this might be more user-friendly, at
the risk of breaking expectations in some cases.
This also fixes a class of security issues where a command like
`cat malicious-file.txt` might output escape sequences, causing
the terminal to echo back a malicious command; such files can still
insert into the command line but at least not execute it directly.
(Since it's only fixed partially I'm not really sure if the security
issue is a good enough motivation for this particular change.)
Note that bracketed paste probably has similar motivation as this feature.
Part of #10987Closes#10991
This introduces a feature flag, "test-require-arg", that removes builtin test's zero and one argument special modes.
That means:
- `test -n` returns false
- `test -z` returns true
- `test -x` with any other option errors out with "missing argument"
- `test foo` errors out as expecting an option
`test -n` returning true is a frequent source of confusion, and so we are breaking with posix in this regard.
As always the flag defaults to off and can be turned on. In future it will default to on and then eventually be made read-only.
There is a new FLOG category "deprecated-test", run `fish -d deprecated-test` and it will show any test call that would change in future.
See the changelog additions for user-visible changes.
Since we enable/disable terminal protocols whenever we pass terminal ownership,
tests can no longer run in parallel on the same terminal.
For the same reason, readline shortcuts in the gdb REPL will not work anymore.
As a remedy, use gdbserver, or lobby for CSI u support in libreadline.
Add sleep to some tests, otherwise they fall (both in CI and locally).
There are two weird failures on FreeBSD remaining, disable them for now
https://github.com/fish-shell/fish-shell/pull/10359/checks?check_run_id=23330096362
Design and implementation borrows heavily from Kakoune.
In future, we should try to implement more of the kitty progressive
enhancements.
Closes#10359
This is the last remnant of the old percent expansion.
It has the downsides of it, in that it is annoying to combine with
anything:
```fish
echo %self/foo
```
prints "%self/foo", not fish's pid.
We have introduced $fish_pid in 3.0, which is much easier to use -
just like a variable, because it is one.
If you need backwards-compatibility for < 3.0, you can use the
following shim:
```fish
set -q fish_pid
or set -g fish_pid %self
```
So we introduce a feature-flag called "remove-percent-self" to turn it
off.
"%self" will simply not be special, e.g. `echo %self` will print
"%self".
Keeps the location of original function definition, and also stores
where it was copied. `functions` and `type` show both locations,
instead of none. It also retains the line numbers in the stack trace.
To recap, this means `&` in the middle of a word no longer
backgrounds.
So:
```fish
echo foo&bar # prints foo&bar
echo foo& bar # backgrounds an echo that prints "foo" and runs "bar"
```
This is opt-in through a new feature flag "ampersand-nobg-in-token".
When this flag and "qmark-noglob" are enabled, this command no longer
needs quoting:
curl https://example.com/thing?foo=bar&duran=duran
Compared to the previous approach e1570a4 ("Let '&' only separate as
the first char of a word"), this has some advantages:
1. "&&" and "&>" are no longer affected. They are still special, even
if used between tokens without spaces, like "echo bar&>foo".
Maybe this is not really *better*, but it avoids risking to annoy
users by breaking the old variant.
2. "&" is still special if at the end of a token, like in "sleep 1&".
Word movement is not affected by the semantics change, so Alt-F and
friends still stop at every "&".
This correctly sets $status when a builtin succeeds but its output fails;
for example if the output is redirected to a file and that write fails.
Fixes#7857
This one tests a bunch of separate stuff, so we put it into a few
different files.
The main, new one is "slices.fish", which tests various index expressions.
