readb is used to read a single byte from stdin, or maybe update universal
variables, or maybe invoke completion handlers, etc. Previously it
returned char_event_t but this is more complex than necessary; instead we
can just have it return a single byte, or one of a few special error
codes. This makes the readb's role more clear.
"The" interrupt handler is used when we get a signal while waiting at the
prompt. Switch it from a global function pointer to an std::function. This
is a mild refactoring which itself will be replaced soon.
Now that timeouts are stored in the event queue peeker, we can remove the
notion of timeout events altogether. Instead you may ask for an event with
a timeout, and get back none on timeout. This simplifies how input events
work.
Previously, when attempting to match a key binding, we would dequeue
events from the queue and put them back on if the binding fails. The
tricky part is timeouts: distinguishing between an escaped character and
the escape key itself. This was handled with "timeout events" and we had
to be careful to know when to discard them.
Switch to a new model: use event_queue_peeker more pervasively.
Temporarily dequeued events are stored in the peeker, and the peeker
itself remembers when it has seen a timeout. This is in preparation for
removing the idea of "timeout events" altogether.
Make it an ordinary struct wrapping a vector, instead of a template.
This is in preparation for using it more widely, for matching bindings
as well as mouse CSI sequences.
Also add some mouse-disabling tests.
select_wrapper_t wraps up the annoying bits of using select(): keeping
track of the max fd, passing null for boring parameters, and
constructing the timeout. Introduce a wrapper struct for this and
replace the existing uses of select() with the wrapper.
In readch_timed, we were passing 1 as the number of fds. This is correct if
the fd is 0 (stdin) which it typically is; however this will fail if in_ is
not stdin. Switch to in_ + 1.
This could have been one iteration off, e.g.
```fish
function on-winch --on-signal winch
echo $LINES
end
```
Resize the terminal, it'll print e.g.
24
then run `echo $LINES` interactively, it might have a different answer.
This isn't beautiful, but it works. A better solution might be to make
the termsize vars electric and just always update them on read?
With something like
```
history | head -n 1
```
this would error "write: Broken pipe", which is just annoying. There
is no *problem* here, `head` closes this on purpose.
Fixes#7924.
Things like
```fish
complete command -n '__fish_seen_subcommand_from subcommand'
--force-files
```
would not be obeyed because we only checked force-files when there was
an option.
Fixes#7920.
When a terminal in a tiling WM starts, it might start the shell before
it has reached its "final" size. So we get the terminal width,
then the terminal would be resized (to appease the tiling logic),
and then we would print the abandon line with the omitted newline
char, only if the size got smaller (likely!), we would overflow the
line and land on the next.
So what we do is a bit of a hack: We don't abandon the first line.
This means that `printf %s foo; fish` will overwrite the `foo`, but
that's a super small problem and I don't see another way around this.
Fixes#7893.
This isn't helpful, and entirely unreadable. Excerpt:
```
__fish_git_prompt_set_char (set -l user_variable_name "$argv[1]" set -l char $argv[2] if set -q argv[3] and begin set -q __fish_git_prompt_show_informative_status or set -q __fi…)
```
Fixes#7911.
When fish starts, it notices which pgroup owns the tty, and then it
restores that pgroup's tty ownership when it exits. However if fish does
not own the tty, then (on Mac at least) the tcsetpgrp call triggers a
SIGSTOP and fish will hang while trying to exit.
The first change is to ignore SIGTTOU instead of defaulting it. This
prevents the hang; however it risks re-introducing #7060.
The second change somewhat mitigates the risk of the first: only do the
restore if the initial pgroup is different than fish's pgroup. This
prevents some useless calls which might potentially steal the tty from
another process (e.g. in #7060).
If fish launches a program and that program marks stdin as O_ASYNC, then
fish will start receiving SIGIO events on Mac. This occurs even though
the file descriptor itself does not have the O_ASYNC flag set.
SIGIO is reported as interrupting select which then breaks multiple-key
bindings, especially in vi-mode.
As the SIGIO based universal notifier is disabled, remove it and the
SIGIO handler itself. This allows fish to ignore properly ignore SIGIO.
Fixes#7853
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
The oldschool math.h imports the math functions into the global
namespace, cmath imports them into std::.
Unfortunately, we already use cmath elsewhere, and including math.h
doesn't reimport them in some systems, so now they can't find them
with std::.
Fixes#7882.
* math: Make function parentheses optional
It's a bit annoying to use parentheses here because that requires
quoting or escaping.
This allows the parens to be omitted, so
math sin pi
is the same as
math 'sin(pi)'
Function calls have the lowest precedence, so
math sin 2 + 6
is the same as
math 'sin(2 + 6)'
* Add more tests
* Add a note to the docs
* even moar docs
Moar docca
* moar tests
Call me Nikola Testla
The bell is a mechanism for important notifications. Not having things
to do in response to a keypress isn't important enough, especially
because we're already flashing and the bell might actually be a bell.
Fixes#7875.
It's not super clear what $SHLVL is useful for, but the current
definition is essentially
"number of shells in the parent processes + 1"
which isn't *super useful*?
Bash's behavior here is a bit weird in that it increments $SHLVL
basically always, but since it auto-execs the last process it will
decrement it again, so in practice it's often not incremented.
E.g.
```
> echo $SHLVL
1
> bash -c 'echo $SHLVL; bash'
2
>> echo $SHLVL
2
```
Both bashes here end up having the same $SHLVL because this is
equivalent to `echo $SHLVL; exec bash`. Running `echo $SHLVL` and then
`bash -c 'echo $SHLVL'` in an interactive bash will have a different
result (1 and 2) because that doesn't *exec* the inner bash.
That's not something we want to get into, so what we do is increment
$SHLVL in every interactive fish. Non-interactive fish will simply
import the existing value.
That means if you had e.g. a bash that runs a fish script that ends up
opening a new fish session, you would have a $SHLVL of *2* - one for the
bash, and one for the inner fish.
We key this off is_interactive_session() (which can also be enabled
via `fish -i`) because it's easy and because `fish -i` is asking for
fish to be, in some form, "interactive".
That means most of the time $SHLVL will be "how many shells am I deep,
how often do I have to `exit`", except for when you specifically asked
for a fish to be "interactive". If that's a problem, we can rethink it.
Fixes#7864.
In preparation for concurrent execution, introduce a
`get_performer_for_builtin` function. This function itself returns a
function, which when called will run the builtin. The idea is that the
function may be called on a background thread (but not in this commit).
Several functions including wgetopt and execve operate on null-terminated
arrays of nul-terminated pointers: a list of pointers to C strings where
the last pointer is null. Prior to this change, each process_t stored its
argv in such an array. This had two problems:
1. It was awkward to work with this type, instead of using std::vector,
etc.
2. The process's arguments would be rearranged by builtins which is
surprising
Our null terminated arrays were built around a fancy type that would copy
input strings and also generate an array of pointers to them, in one big
allocation.
Switch to a new model where we construct an array of pointers over
existing strings. So you can supply a `vector<string>` and now
`null_terminated_array_t` will just make a list of pointers to them. Now
processes can just store their argv in a familiar wcstring_list_t.
Prior to this change, builtins would take their arguments as `wchar_t **`.
This implies that the order of the arguments may be changed (which is
true, `wgetopter` does so) but also that the strings themselves may be
changed, which no builtin should do.
Switch them all to take `const wchar_t **` instead: now the arguments may
be rearranged but their contents may no longer be modified.
This cleans up builtin_set a bit, with the meat of the change being
reworking `parse_index` into `split_var_and_indexes`.
`parse_index` was a function that split a string like `foo[1 3..5]` into
its variable name `foo` and the indexes (here `1 3 4 5`). It had a funny
interface where it would modify a C string in-place. Switch it to return a
`split_var_t` which is a little struct wrapping up the split operation.
This simplifies memory management, and also avoids modifying the arguments
to the builtin.
Previously iothread_perform could do something on a background thread, and
then do something on the main thread. But we no longer use that second
part: instead everything goes through debounce. Remove the completion
parameter from iothread_perform.
This fixes the following problem: if a command is entered while the
previous command is still executing, fish will see it all at once and
execute it before syntax highlighting as a chance to start. So the
command will appear wrong on the terminal. Fix this by detecting this
case and performing a fast no-io highlight.
An example of how to reproduce this:
run `sleep 3` and then type `echo foo` while the sleep is still running.
- Check for special characters *before* attempting to parse
- Also ignore lines with `{` and `*`
- Also skip lines with `<<` because that might be a heredoc (or a
- `<<<` herestring)
Fixes#7874.
This cleans up some exit code processing. Previously a failed exec
would produce exit code 125 unconditionally, while a failed posix_spawn
would produce exit code 1 (!).
With this change, fish reports exit code 126 for not-executable, and 127
for file-not-found. This matches bash.
This change modifies the fish safety check surrounding execve / spawn so
it can run shell scripts having concatenated binary content. We're using
the same safety check as FreeBSD /bin/sh [1] and the Z-shell [5]. POSIX
was recently revised to require this behavior:
"The input file may be of any type, but the initial portion of the
file intended to be parsed according to the shell grammar (XREF to
XSH 2.10.2 Shell Grammar Rules) shall consist of characters and
shall not contain the NUL character. The shell shall not enforce
any line length limits."
"Earlier versions of this standard required that input files to the
shell be text files except that line lengths were unlimited.
However, that was overly restrictive in relation to the fact that
shells can parse a script without a trailing newline, and in
relation to a common practice of concatenating a shell script
ending with an 'exit' or 'exec $command' with a binary data payload
to form a single-file self-extracting archive." [2] [3]
One example use case of such scripts, is the Cosmopolitan C Library [4]
which configuse the GNU Linker to output a polyglot shell+binary format
that runs on Linux / Mac / Windows / FreeBSD / OpenBSD / NetBSD / BIOS.
Fixesjart/cosmopolitan#88
[1] 9a1cd36331
[2] http://austingroupbugs.net/view.php?id=1250
[3] http://austingroupbugs.net/view.php?id=1226#c4394
[4] https://justine.lol/cosmopolitan/index.html
[5] 326d9c203b
cd: Just try to cd without checking first
Some filesystems are broken and error out on `stat(3)` of existing and
cd-able directories.
So we just try to `fchdir` and report errors later.
Fixes#7577.
