Add the input function undo which is bound to `\c_` (control + / on
some terminals). Redoing the most recent chain of undos is supported,
redo is bound to `\e/` for now.
Closes#1367.
This approach should not have the issues discussed in #5897.
Every single modification to the commandline can be undone individually,
except for adjacent single-character inserts, which are coalesced,
so they can be reverted with a single undo. Coalescing is not done for
space characters, so each word can be undone separately.
When moving between history search entries, only the current history
search entry is reachable via the undo history. This allows to go back
to the original search string with a single undo, or by pressing the
escape key.
Similarly, when moving between pager entries, only the most recent
selection in the pager can be undone.
fd_monitor is a new class which can monitor a set of fds, waiting for them
to become readable. When an fd becomes readable, a callback is invoked.
Timeouts are also supported.
This is intended to replace the "bufferfill" threads. Rather than one
thread per bufferfill, we will have a single fd_monitor which can service
multiple bufferfills. This helps today with nested command substitutions,
and will help in the future with concurrent execution.
Prior to this fix, the cancellation C++ test would mark the parser as
interactive in an effort to install interactive signal handling (so that,
for example, SIGINT would stop the job and return control to the user).
However this flag would also cause fish to attempt to save and restore tty modes
across the job. This would fail since there is no tty, and so the job would fail
with an unexpected error code.
We don't need to mark the parser as interactive, we can just remove that line.
Fixes#6539.
Prior to this fix, fish was rather inconsistent in when $status gets set
in response to an error. For example, a failed expansion like "$foo["
would not modify $status.
This makes the following inter-related changes:
1. String expansion now directly returns the value to set for $status on
error. The value is always used.
2. parser_t::eval() now directly returns the proc_status_t, which cleans
up a lot of call sites.
3. We expose a new function exec_subshell_for_expand() which ignores
$status but returns errors specifically related to subshell expansion.
4. We reify the notion of "expansion breaking" errors. These include
command-not-found, expand syntax errors, and others.
The upshot is we are more consistent about always setting $status on
errors.
This commit recognizes an existing pattern: many operations need some
combination of a set of variables, a way to detect cancellation, and
sometimes a parser. For example, tab completion needs a parser to execute
custom completions, the variable set, should cancel on SIGINT. Background
autosuggestions don't need a parser, but they do need the variables and
should cancel if the user types something new. Etc.
This introduces a new triple operation_context_t that wraps these concepts
up. This simplifies many method signatures and argument passing.
Empty items are used as sentinels to indicate that we've reached the end of
history, so they should not be added as actual items. Enforce this.
Fixes#6032
user_supplied was used to distinguish IO redirections which were
explicit, vs those that came about through "transmogrphication." But
transmogrification is no more. Remove the flag.
parser_t::eval indicates whether there was a parse error. It can be
easily confused with the status of the execution. Use a real type to
make it more clear.
Prior to this fix, a file redirection was turned into an io_file_t. This is
annoying because every place where we want to apply the redirection, we
might fail due to open() failing. Switch to opening the file at the point
we resolve the redirection spec. This will simplify a lot of code.
fish has to ensure that the pipes it creates do not conflict with any
explicit fds named in redirections. Switch this code to using
autoclose_fd_t to make the ownership logic more explicit, and also
introduce fd_set_t to reduce the dependence on io_chain_t.
This adds initial support for statements with prefixed variable assignments.
Statments like this are supported:
a=1 b=$a echo $b # outputs 1
Just like in other shells, the left-hand side of each assignment must
be a valid variable identifier (no quoting/escaping). Array indexing
(PATH[1]=/bin ls $PATH) is *not* yet supported, but can be added fairly
easily.
The right hand side may be any valid string token, like a command
substitution, or a brace expansion.
Since `a=* foo` is equivalent to `begin set -lx a *; foo; end`,
the assignment, like `set`, uses nullglob behavior, e.g. below command
can safely be used to check if a directory is empty.
x=/nothing/{,.}* test (count $x) -eq 0
Generic file completion is done after the equal sign, so for example
pressing tab after something like `HOME=/` completes files in the
root directory
Subcommand completion works, so something like
`GIT_DIR=repo.git and command git ` correctly calls git completions
(but the git completion does not use the variable as of now).
The variable assignment is highlighted like an argument.
Closes#6048
