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use shell_command::ShellCommand;
use nom::IResult;
use std::process::Command;
use std::env;
use std::env::VarError;
fn token_char(ch: char) -> bool {
if ch.len_utf8() > 1 {
return false;
}
match ch {
'\x00' ... '\x20' => false,
'\x7f' | '"' | '\'' | '>' | '<' | '|' | ';' | '{' | '}' | '$' => false,
_ => true,
}
}
fn var_char(ch: char) -> bool {
match ch {
'a' ... 'z' => true,
'A' ... 'Z' => true,
'0' ... '9' => true,
'_' => true,
_ => false,
}
}
enum TokenPart {
Bare(String),
Placeholder,
EnvVariable(String),
}
struct Token(Vec<TokenPart>);
impl Token {
fn into_string(self, args: &mut Iterator<Item = &str>)
-> Result<String, VarError> {
let mut token = String::from("");
for part in self.0 {
match part {
TokenPart::Bare(s) => token += &s,
TokenPart::Placeholder =>
token += args.next().expect("Too many placeholders"),
TokenPart::EnvVariable(name) => {
debug!("Environment variable {}", name);
token += &env::var(name)?
}
}
}
Ok(token)
}
}
named!(bare_token<&str, TokenPart>,
map!(take_while1_s!(token_char), |s| TokenPart::Bare(String::from(s))));
named!(quoted_token<&str, TokenPart>,
map!(delimited!(tag_s!("\""), take_until_s!("\""), tag_s!("\"")),
|s| TokenPart::Bare(String::from(s))));
named!(place_holder<&str, TokenPart>,
map!(tag_s!("{}"), |_| TokenPart::Placeholder));
named!(env_var<&str, TokenPart>,
map!(preceded!(tag!("$"), take_while1_s!(var_char)),
|name| TokenPart::EnvVariable(String::from(name))));
named!(command_token<&str, Token>,
map!(many1!(alt!(bare_token | quoted_token | place_holder | env_var)),
|vec| Token(vec)));
named!(command< &str, Vec<Token> >,
terminated!(ws!(many1!(command_token)), eof!()));
#[macro_export]
macro_rules! cmd {
($format:expr) => ($crate::new_command($format, &[]).unwrap());
($format:expr, $($arg:expr),+) =>
($crate::new_command($format, &[$($arg),+]).unwrap());
}
fn parse_cmd<'a>(format: &'a str, args: &'a [&str])
-> Result<Vec<String>, VarError> {
let tokens = match command(format) {
IResult::Done(_, result) => result,
IResult::Error(error) => panic!("Error {:?}", error),
IResult::Incomplete(needed) => panic!("Needed {:?}", needed)
};
let args = args.iter().map(|a| *a).collect::<Vec<_>>();
let mut args = args.into_iter();
tokens.into_iter().map(|token| token.into_string(&mut args))
.collect::<Result<Vec<_>, _>>()
}
pub fn new_command(format: &str, args: &[&str])
-> Result<ShellCommand, VarError> {
let vec = parse_cmd(format, args)?;
let mut command = Command::new(&vec[0]);
if vec.len() > 1 {
command.args(&vec[1..]);
}
let line = vec.join(" ");
Ok(ShellCommand::new(line, command))
}
#[test]
fn test_parse_cmd() {
let tokens = parse_cmd(r#"cmd 1 2
3 "
4" {}"#, &["5"]).unwrap();
assert_eq!("cmd", tokens[0]);
assert_eq!("1", tokens[1]);
assert_eq!("2", tokens[2]);
assert_eq!("3", tokens[3]);
assert_eq!("\n 4", tokens[4]);
assert_eq!("5", tokens[5]);
}
#[test]
fn test_parse_cmd_env() {
use env_logger;
env_logger::init().unwrap();
env::set_var("MY_VAR", "VALUE");
let tokens = parse_cmd("echo $MY_VAR/dir", &[]).unwrap();
assert_eq!("VALUE/dir", tokens[1]);
}