The parser is still very much a work-in-progress, but it can currently
parse most of the basic bits, the only *completely* unimplemented things
in the parser are:
- heredocs (io_here)
- alias expansion
- arithmetic expansion
There are a whole suite of bugs, and syntax highlighting is unreliable
at best.
For now, this is not attached anywhere, a future commit will enable it
for /bin/sh or a `Shell --posix` invocation.
The builtin is based on the behaviour of the z-shell.
Namely it tries to resolve every argument one by one.
When resolving (in the order below) the following results can occur:
1. The argument is a shell built-in command. Then print it.
2. The argument is an alias. In this case we print the mapped value.
3. The argument was found in the `PATH` environment variable.
In this case we print the resolved absolute path
and try to find more occurences in the `PATH` environment variable.
4. None of the above. If no earlier argument got resolved,
we print the error `{argument} not found`.
If at least one argument got resolved we exit with exit code 0,
otherwise 1.
By not using Core::File to resolve the executable in the environment
but rather using a modified version of the code we print every
matching executable of the given name. This behaviour matches
up with the z-shell.
The builtin has the following flags to modify the behaviour according
to the users needs:
- `-p --path-only`: This skips the built-in and alias checks
(step 1 & 2)
- `-s --follow-symlink`: This follows the symlinks of an executable to
its symlink-free location.
- `-w --type`: This displays the type of the found object
without any additional descriptive information.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
We previously had at least three different implementations for resolving
executables in the PATH, all of which had slightly different
characteristics.
Merge those into a single implementation to keep the behaviour
consistent, and maybe to make that implementation more configurable in
the future.
The shell now expects a JSON object of the form {"kind":<kind>,...} per
line in the standard output of the completion process, where 'kind' is
one of:
- "plain": Just a plain suggestion.
- "program": Prompts the shell to complete a program name starting with
the given "name".
- "proxy": Prompts the shell to act as if a completion for "argv" was
requested.
- "path": Prompts the shell to complete a path given the "base" and
"part" (same as completing part in cwd=base).
This feature needs a bit more work, so let's disable it by default.
Note that the shell will still use _complete_foo if it is defined
regardless of this setting.
This commit limits the autocomplete processes to effectively have
readonly access to the fs, and only enough pledges to get the dynamic
loader working.
A program can either respond to `--complete -- some args to complete`
directly, or add a `_complete_<program name>` invokable (i.e. shell
function, or just a plain binary in PATH) that completes the given
command and lists the completions on stdout.
Should such a completion fail or yield no results, we'll fall back to
the previous completion algorithm.
Shell can now use LibLine's `on_paste` hook to more intelligently escape
pasted data, with the following heuristics:
- If the current command is invalid, just pile the pasted string on top
- If the cursor is *after* a command node, escape the pasted data,
whichever way yields a smaller encoding
- If the cursor is at the start of or in the middle of a command name,
paste the data as-is, assuming that the user wants to paste code
- If the cursor is otherwise in some argument, escape the pasted data
according to which kind of string the cursor is in the middle of
(double-quoted, single-quoted or a simple bareword)
This makes interrupting `sleep 10; echo hi` not print `hi` anymore,
which is the expected behaviour anyway.
Also fixes the problem with fast-running loops "eating" interrupts and
not quitting.
Naturally, this means that a command with a failing redirection will
not start, and so will terminate the pipeline (if any).
This also applies to the `exit` run when the shell is closed, fixing a
fun bug there as well (thanks to Discord user Salanty for pointing that
out) where closing the terminal (i.e. I/O error on the tty) with a
failing `exit` command would make the shell retry executing `exit` every
time, leading to an eventual stack overflow.
This commit makes the Shell check for errors after a node is run(), and
prevents further execution by unwinding until the error is cleared.
Fixes#10649.
Instead of the previous only-escape-with-backslashes, extend the
escaping to one of:
- No escape
- Escape with backslash
- Escape with "\xhh" if control character that isn't easily represented
as \X
- Escape with "\uhhhhhhhh" if unicode character that is too big to
represent as "\xhh".
Fixes#6986.
We had some inconsistencies before:
- Sometimes "The", sometimes "the"
- Sometimes trailing ".", sometimes no trailing "."
I picked the most common one (lowecase "the", trailing ".") and applied
it to all copyright headers.
By using the exact same string everywhere we can ensure nothing gets
missed during a global search (and replace), and that these
inconsistencies are not spread any further (as copyright headers are
commonly copied to new files).
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
Now a variable may have an optional slice (only _one_ slice), which can
also use negative indices to index from the end.
This works on both lists and strings.
The contents of the slice have the same semantics as brace expansions.
For example:
```sh
$ x=(1 2 3 4 5 6)
$ echo $x[1..3] # select indices 1, 2, 3
2 3 4
$ echo $x[3,4,1,0] # select indices 3, 4, 1, 0 (in that order)
4 5 2 1
$ x="Well Hello Friends!"
$ echo $x[5..9]
Hello
```
This commit adds a few basic variable substitution operations:
- length
Find the length of a string or a list
- length_across
Find the lengths of things inside a list
- remove_{suffix,prefix}
Remove a suffix or a prefix from all the passed values
- regex_replace
Replace all matches of a given regex with a given template
- split
Split the given string with the given delimiter (or to its
code points if the delimiter is empty)
- concat_lists
concatenates any given lists into one
Closes#4316 (the ancient version of this same feature)
Non-interactive shells (i.e. when running scripts) do not need this
functionality, so they are a boatload of wasted time.
This significantly reduces the script startup and shutdown times when
there are lots of executables in PATH or lots of entries in the history.
