nushell/crates/nu-engine/src/env.rs
JT 9888f8f298
Add pipeline redirection support (#4594)
* redirection

* Remove commented-out

* fix tests

* more fixes
2022-02-21 17:22:21 -05:00

191 lines
6.4 KiB
Rust

use std::collections::HashMap;
use std::path::{Path, PathBuf};
use nu_protocol::ast::PathMember;
use nu_protocol::engine::{EngineState, Stack};
use nu_protocol::{Config, PipelineData, ShellError, Value};
use crate::eval_block;
#[cfg(windows)]
const ENV_SEP: &str = ";";
#[cfg(not(windows))]
const ENV_SEP: &str = ":";
const ENV_CONVERSIONS: &str = "ENV_CONVERSIONS";
enum ConversionResult {
Ok(Value),
ConversionError(ShellError), // Failure during the conversion itself
GeneralError(ShellError), // Other error not directly connected to running the conversion
CellPathError, // Error looking up the ENV_VAR.to_/from_string fields in $env.ENV_CONVERSIONS
}
/// Translate environment variables from Strings to Values. Requires config to be already set up in
/// case the user defined custom env conversions in config.nu.
///
/// It returns Option instead of Result since we do want to translate all the values we can and
/// skip errors. This function is called in the main() so we want to keep running, we cannot just
/// exit.
pub fn convert_env_values(engine_state: &mut EngineState, stack: &Stack) -> Option<ShellError> {
let mut error = None;
let mut new_scope = HashMap::new();
for (name, val) in &engine_state.env_vars {
match get_converted_value(engine_state, stack, name, val, "from_string") {
ConversionResult::Ok(v) => {
let _ = new_scope.insert(name.to_string(), v);
}
ConversionResult::ConversionError(e) => error = error.or(Some(e)),
ConversionResult::GeneralError(_) => continue,
ConversionResult::CellPathError => {
let _ = new_scope.insert(name.to_string(), val.clone());
}
}
}
for (k, v) in new_scope {
engine_state.env_vars.insert(k, v);
}
error
}
/// Translate one environment variable from Value to String
pub fn env_to_string(
env_name: &str,
value: Value,
engine_state: &EngineState,
stack: &Stack,
config: &Config,
) -> Result<String, ShellError> {
match get_converted_value(engine_state, stack, env_name, &value, "to_string") {
ConversionResult::Ok(v) => Ok(v.as_string()?),
ConversionResult::ConversionError(e) => Err(e),
ConversionResult::GeneralError(e) => Err(e),
ConversionResult::CellPathError => Ok(value.into_string(ENV_SEP, config)),
}
}
/// Translate all environment variables from Values to Strings
pub fn env_to_strings(
engine_state: &EngineState,
stack: &Stack,
config: &Config,
) -> Result<HashMap<String, String>, ShellError> {
let env_vars = stack.get_env_vars(engine_state);
let mut env_vars_str = HashMap::new();
for (env_name, val) in env_vars {
let val_str = env_to_string(&env_name, val, engine_state, stack, config)?;
env_vars_str.insert(env_name, val_str);
}
Ok(env_vars_str)
}
/// Shorthand for env_to_string() for PWD with custom error
pub fn current_dir_str(engine_state: &EngineState, stack: &Stack) -> Result<String, ShellError> {
let config = stack.get_config()?;
if let Some(pwd) = stack.get_env_var(engine_state, "PWD") {
match env_to_string("PWD", pwd, engine_state, stack, &config) {
Ok(cwd) => {
if Path::new(&cwd).is_absolute() {
Ok(cwd)
} else {
println!("cwd is: {}", cwd);
Err(ShellError::LabeledError(
"Invalid current directory".to_string(),
format!("The 'PWD' environment variable must be set to an absolute path. Found: '{}'", cwd)
))
}
}
Err(e) => Err(e),
}
} else {
Err(ShellError::LabeledError(
"Current directory not found".to_string(),
"The environment variable 'PWD' was not found. It is required to define the current directory.".to_string(),
))
}
}
/// Calls current_dir_str() and returns the current directory as a PathBuf
pub fn current_dir(engine_state: &EngineState, stack: &Stack) -> Result<PathBuf, ShellError> {
current_dir_str(engine_state, stack).map(PathBuf::from)
}
fn get_converted_value(
engine_state: &EngineState,
stack: &Stack,
name: &str,
orig_val: &Value,
direction: &str,
) -> ConversionResult {
if let Some(env_conversions) = stack.get_env_var(engine_state, ENV_CONVERSIONS) {
let env_span = match env_conversions.span() {
Ok(span) => span,
Err(e) => {
return ConversionResult::GeneralError(e);
}
};
let val_span = match orig_val.span() {
Ok(span) => span,
Err(e) => {
return ConversionResult::GeneralError(e);
}
};
let path_members = &[
PathMember::String {
val: name.to_string(),
span: env_span,
},
PathMember::String {
val: direction.to_string(),
span: env_span,
},
];
if let Ok(Value::Block {
val: block_id,
span: from_span,
..
}) = env_conversions.follow_cell_path(path_members)
{
let block = engine_state.get_block(block_id);
if let Some(var) = block.signature.get_positional(0) {
let mut stack = stack.gather_captures(&block.captures);
if let Some(var_id) = &var.var_id {
stack.add_var(*var_id, orig_val.clone());
}
let result = eval_block(
engine_state,
&mut stack,
block,
PipelineData::new(val_span),
true,
true,
);
match result {
Ok(data) => ConversionResult::Ok(data.into_value(val_span)),
Err(e) => ConversionResult::ConversionError(e),
}
} else {
// This one is OK to fail: We want to know if custom conversion is working
ConversionResult::ConversionError(ShellError::MissingParameter(
"block input".into(),
from_span,
))
}
} else {
ConversionResult::CellPathError
}
} else {
ConversionResult::CellPathError
}
}