nushell/crates/nu-engine/src/env.rs
Jakub Žádník 90b2ec537f
Do not pass non-string env vars to externals (#4748)
* Do not pass non-string env vars to externals

Also misc cleanup

* Add note to default config

* Add a test

* Ensure PATH/Path conversion list <-> string
2022-03-12 00:18:39 +02:00

329 lines
11 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::{PipelineData, ShellError, Span, Value};
use crate::eval_block;
#[cfg(windows)]
const ENV_PATH_NAME: &str = "Path";
#[cfg(windows)]
const ENV_PATH_NAME_SECONDARY: &str = "PATH";
#[cfg(not(windows))]
const ENV_PATH_NAME: &str = "PATH";
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());
}
}
}
#[cfg(not(windows))]
{
error = error.or_else(|| ensure_path(&mut new_scope, ENV_PATH_NAME));
}
#[cfg(windows)]
{
let first_result = ensure_path(&mut new_scope, ENV_PATH_NAME);
if first_result.is_some() {
let second_result = ensure_path(&mut new_scope, ENV_PATH_NAME_SECONDARY);
if second_result.is_some() {
error = error.or(first_result);
}
}
}
for (k, v) in new_scope {
engine_state.env_vars.insert(k, v);
}
error
}
/// Translate one environment variable from Value to String
///
/// Returns Ok(None) if the env var is not
pub fn env_to_string(
env_name: &str,
value: &Value,
engine_state: &EngineState,
stack: &Stack,
) -> 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 => match value.as_string() {
Ok(s) => Ok(s),
Err(_) => {
if env_name == ENV_PATH_NAME {
// Try to convert PATH/Path list to a string
match value {
Value::List { vals, .. } => {
let paths = vals
.iter()
.map(|v| v.as_string())
.collect::<Result<Vec<_>, _>>()?;
match std::env::join_paths(paths) {
Ok(p) => Ok(p.to_string_lossy().to_string()),
Err(_) => Err(ShellError::EnvVarNotAString(
env_name.to_string(),
value.span()?,
)),
}
}
_ => Err(ShellError::EnvVarNotAString(
env_name.to_string(),
value.span()?,
)),
}
} else {
Err(ShellError::EnvVarNotAString(
env_name.to_string(),
value.span()?,
))
}
}
},
}
}
/// Translate all environment variables from Values to Strings
pub fn env_to_strings(
engine_state: &EngineState,
stack: &Stack,
) -> 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 {
match env_to_string(&env_name, &val, engine_state, stack) {
Ok(val_str) => {
env_vars_str.insert(env_name, val_str);
}
Err(ShellError::EnvVarNotAString(..)) => {} // ignore non-string values
Err(e) => return Err(e),
}
}
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> {
if let Some(pwd) = stack.get_env_var(engine_state, "PWD") {
match env_to_string("PWD", &pwd, engine_state, stack) {
Ok(cwd) => {
if Path::new(&cwd).is_absolute() {
Ok(cwd)
} else {
Err(ShellError::SpannedLabeledError(
"Invalid current directory".to_string(),
format!("The 'PWD' environment variable must be set to an absolute path. Found: '{}'", cwd),
pwd.span()?
))
}
}
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)
}
/// Get the contents of path environment variable as a list of strings
///
/// On non-Windows: It will fetch PATH
/// On Windows: It will try to fetch Path first but if not present, try PATH
pub fn path_str(
engine_state: &EngineState,
stack: &Stack,
span: Span,
) -> Result<String, ShellError> {
let (pathname, pathval) = match stack.get_env_var(engine_state, ENV_PATH_NAME) {
Some(v) => Ok((ENV_PATH_NAME, v)),
None => {
#[cfg(windows)]
match stack.get_env_var(engine_state, ENV_PATH_NAME_SECONDARY) {
Some(v) => Ok((ENV_PATH_NAME_SECONDARY, v)),
None => Err(ShellError::EnvVarNotFoundAtRuntime(
ENV_PATH_NAME_SECONDARY.to_string(),
span,
)),
}
#[cfg(not(windows))]
Err(ShellError::EnvVarNotFoundAtRuntime(
ENV_PATH_NAME.to_string(),
span,
))
}
}?;
env_to_string(pathname, &pathval, engine_state, stack)
}
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 {
ConversionResult::ConversionError(ShellError::MissingParameter(
"block input".into(),
from_span,
))
}
} else {
ConversionResult::CellPathError
}
} else {
ConversionResult::CellPathError
}
}
fn ensure_path(scope: &mut HashMap<String, Value>, env_path_name: &str) -> Option<ShellError> {
let mut error = None;
// If PATH/Path is still a string, force-convert it to a list
match scope.get(env_path_name) {
Some(Value::String { val, span }) => {
// Force-split path into a list
let span = *span;
let paths = std::env::split_paths(val)
.map(|p| Value::String {
val: p.to_string_lossy().to_string(),
span,
})
.collect();
scope.insert(env_path_name.to_string(), Value::List { vals: paths, span });
}
Some(Value::List { vals, span }) => {
// Must be a list of strings
if !vals.iter().all(|v| matches!(v, Value::String { .. })) {
error = error.or_else(|| {
Some(ShellError::SpannedLabeledError(
format!("Wrong {} environment variable value", env_path_name),
format!("{} must be a list of strings", env_path_name),
*span,
))
});
}
}
Some(val) => {
// All other values are errors
let span = match val.span() {
Ok(sp) => sp,
Err(e) => {
error = error.or(Some(e));
Span::test_data() // FIXME: any better span to use here?
}
};
error = error.or_else(|| {
Some(ShellError::SpannedLabeledError(
format!("Wrong {} environment variable value", env_path_name),
format!("{} must be a list of strings", env_path_name),
span,
))
});
}
None => { /* not preset, do nothing */ }
}
error
}