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nushell/crates/nu-command/src/filesystem/mktemp.rs
Taylor 494a5a5286
Add mktemp command ()
closes  

I've opened this a little prematurely to get some questions answered
before I cleanup the code.

As I started trying to better understand GNUs `mktemp` I've realized its
kind of peculiar and we might want to change its behavior to introduce
it to nushell.

#### quiet and dry run

Does it make sense to keep the `quiet` and `dry_run` flags? I don't
think so. The GNU documentation says this about the dry run flag "Using
the output of this command to create a new file is inherently unsafe, as
there is a window of time between generating the name and using it where
another process can create an object by the same name." So yeah why keep
it? As far as quiet goes, does it make sense to silence the errors in
nushell?

#### other confusing flags

According to the [gnu
docs](https://www.gnu.org/software/coreutils/manual/html_node/mktemp-invocation.html),
the `-t` flag is deprecated and the `-p`/ `--tempdir` are the same flag
with the only difference being `--tempdir` takes an optional path, Given
that, I've broken the `-p` away from `--tempdir`. Now there is one
switch `--tmpdir`/`-t` and one named param `--tmpdir-path`/`-p`.

GNU mktemp
```
  -p DIR, --tmpdir[=DIR]  interpret TEMPLATE relative to DIR; if DIR is not
                        specified, use $TMPDIR if set, else /tmp.  With
                        this option, TEMPLATE must not be an absolute name;
                        unlike with -t, TEMPLATE may contain slashes, but
                        mktemp creates only the final component
  -t                  interpret TEMPLATE as a single file name component,
                        relative to a directory: $TMPDIR, if set; else the
                        directory specified via -p; else /tmp [deprecated]

```
to
nushell mktemp
```
  -p, --tmpdir-path <Filepath> # named param, must provide a path
  -t, --tmpdir                 # a switch
```

Is this a terrible idea?

What should I do?

---------

Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
2023-11-17 19:30:53 -06:00

130 lines
4.5 KiB
Rust

use nu_engine::env::current_dir;
use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type, Value,
};
use std::path::PathBuf;
#[derive(Clone)]
pub struct Mktemp;
impl Command for Mktemp {
fn name(&self) -> &str {
"mktemp"
}
fn usage(&self) -> &str {
"Create temporary files or directories using uutils/coreutils mktemp."
}
fn search_terms(&self) -> Vec<&str> {
vec![
"coreutils",
"create",
"directory",
"file",
"folder",
"temporary",
]
}
fn signature(&self) -> Signature {
Signature::build("mktemp")
.input_output_types(vec![(Type::Nothing, Type::String)])
.optional(
"template",
SyntaxShape::String,
"Optional pattern from which the name of the file or directory is derived. Must contain at least three 'X's in last component.",
)
.named("suffix", SyntaxShape::String, "Append suffix to template; must not contain a slash.", None)
.named("tmpdir-path", SyntaxShape::Filepath, "Interpret TEMPLATE relative to tmpdir-path. If tmpdir-path is not set use $TMPDIR", Some('p'))
.switch("tmpdir", "Interpret TEMPLATE relative to the system temporary directory.", Some('t'))
.switch("directory", "Create a directory instead of a file.", Some('d'))
.category(Category::FileSystem)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Make a temporary file with the given suffix in the current working directory.",
example: "mktemp --suffix .txt",
result: Some(Value::test_string("<WORKING_DIR>/tmp.lekjbhelyx.txt")),
},
Example {
description: "Make a temporary file named testfile.XXX with the 'X's as random characters in the current working directory.",
example: "mktemp testfile.XXX",
result: Some(Value::test_string("<WORKING_DIR>/testfile.4kh")),
},
Example {
description: "Make a temporary file with a template in the system temp directory.",
example: "mktemp -t testfile.XXX",
result: Some(Value::test_string("/tmp/testfile.4kh")),
},
Example {
description: "Make a temporary directory with randomly generated name in the temporary directory.",
example: "mktemp -d",
result: Some(Value::test_string("/tmp/tmp.NMw9fJr8K0")),
},
]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
_input: PipelineData,
) -> Result<PipelineData, ShellError> {
let span = call.head;
let template = call
.rest(engine_state, stack, 0)?
.first()
.cloned()
.map(|i: Spanned<String>| i.item)
.unwrap_or("tmp.XXXXXXXXXX".to_string()); // same as default in coreutils
let directory = call.has_flag("directory");
let suffix = call.get_flag(engine_state, stack, "suffix")?;
let tmpdir = call.has_flag("tmpdir");
let tmpdir_path = call
.get_flag(engine_state, stack, "tmpdir-path")?
.map(|i: Spanned<PathBuf>| i.item);
let tmpdir = if tmpdir_path.is_some() {
tmpdir_path
} else if directory || tmpdir {
Some(std::env::temp_dir())
} else {
Some(current_dir(engine_state, stack)?)
};
let options = uu_mktemp::Options {
directory,
dry_run: false,
quiet: false,
suffix,
template,
tmpdir,
treat_as_template: true,
};
let res = match uu_mktemp::mktemp(&options) {
Ok(res) => res
.into_os_string()
.into_string()
.map_err(|e| ShellError::IOErrorSpanned(e.to_string_lossy().to_string(), span))?,
Err(e) => {
return Err(ShellError::GenericError(
format!("{}", e),
format!("{}", e),
None,
None,
Vec::new(),
));
}
};
Ok(PipelineData::Value(Value::string(res, span), None))
}
}