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#![feature(deque_extras)]
#![feature(box_syntax)]
#![feature(plugin)]
#![plugin(peg_syntax_ext)]
use std::collections::HashMap;
use std::fs::File;
use std::io::{stdout, Read, Write};
use std::env;
use std::process;
use self::directory_stack::DirectoryStack;
use self::input_editor::readln;
use self::peg::{parse, Job};
use self::variables::Variables;
use self::history::History;
use self::flow_control::{FlowControl, is_flow_control_command, Statement};
pub mod directory_stack;
pub mod to_num;
pub mod input_editor;
pub mod peg;
pub mod variables;
pub mod history;
pub mod flow_control;
/// This struct will contain all of the data structures related to this
/// instance of the shell.
pub struct Shell {
variables: Variables,
flow_control: FlowControl,
directory_stack: DirectoryStack,
history: History,
}
impl Shell {
/// Panics if DirectoryStack construction fails
pub fn new() -> Self {
Shell {
variables: Variables::new(),
flow_control: FlowControl::new(),
directory_stack: DirectoryStack::new().expect(""),
history: History::new(),
}
}
pub fn print_prompt(&self) {
self.print_prompt_prefix();
match self.flow_control.current_statement {
Statement::For(_, _) => self.print_for_prompt(),
Statement::Default => self.print_default_prompt(),
}
if let Err(message) = stdout().flush() {
println!("{}: failed to flush prompt to stdout", message);
}
}
// TODO eventually this thing should be gone
fn print_prompt_prefix(&self) {
let prompt_prefix = self.flow_control.modes.iter().rev().fold(String::new(), |acc, mode| {
acc +
if mode.value {
"+ "
} else {
"- "
}
});
print!("{}", prompt_prefix);
}
fn print_for_prompt(&self) {
print!("for> ");
}
fn print_default_prompt(&self) {
let cwd = env::current_dir().ok().map_or("?".to_string(),
|ref p| p.to_str().unwrap_or("?").to_string());
print!("ion:{}# ", cwd);
}
fn on_command(&mut self, command_string: &str, commands: &HashMap<&str, Command>) {
self.history.add(command_string.to_string());
let mut jobs = parse(command_string);
// Execute commands
for job in jobs.drain(..) {
if self.flow_control.collecting_block {
// TODO move this logic into "end" command
if job.command == "end" {
self.flow_control.collecting_block = false;
let block_jobs: Vec<Job> = self.flow_control
.current_block
.jobs
.drain(..)
.collect();
let mut variable = String::new();
let mut values: Vec<String> = vec![];
if let Statement::For(ref var, ref vals) = self.flow_control.current_statement {
variable = var.clone();
values = vals.clone();
}
for value in values {
self.variables.set_var(&variable, &value);
for job in block_jobs.iter() {
self.run_job(job, commands);
}
}
self.flow_control.current_statement = Statement::Default;
} else {
self.flow_control.current_block.jobs.push(job);
}
} else {
if self.flow_control.skipping() && !is_flow_control_command(&job.command) {
continue;
}
self.run_job(&job, commands);
}
}
}
fn run_job(&mut self, job: &Job, commands: &HashMap<&str, Command>) {
let job = self.variables.expand_job(job);
if let Some(command) = commands.get(job.command.as_str()) {
(*command.main)(job.args.as_slice(), self);
} else {
self.run_external_commmand(&job.args);
}
}
fn run_external_commmand(&mut self, args: &Vec<String>) {
if let Some(path) = args.get(0) {
let mut command = process::Command::new(path);
for i in 1..args.len() {
if let Some(arg) = args.get(i) {
command.arg(arg);
}
}
match command.spawn() {
Ok(mut child) => {
match child.wait() {
Ok(status) => {
if let Some(code) = status.code() {
self.variables.set_var("?", &code.to_string());
} else {
println!("{}: No child exit code", path);
}
}
Err(err) => println!("{}: Failed to wait: {}", path, err),
}
}
Err(err) => println!("{}: Failed to execute: {}", path, err),
}
}
}
}
/// Structure which represents a Terminal's command.
/// This command structure contains a name, and the code which run the
/// functionnality associated to this one, with zero, one or several argument(s).
/// # Example
/// ```
/// let my_command = Command {
/// name: "my_command",
/// help: "Describe what my_command does followed by a newline showing usage",
/// main: box|args: &[String], &mut Shell| {
/// println!("Say 'hello' to my command! :-D");
/// }
/// }
/// ```
pub struct Command {
pub name: &'static str,
pub help: &'static str,
pub main: Box<Fn(&[String], &mut Shell)>,
}
impl Command {
/// Return the map from command names to commands
pub fn map() -> HashMap<&'static str, Self> {
let mut commands: HashMap<&str, Self> = HashMap::new();
commands.insert("cd",
Command {
name: "cd",
help: "To change the current directory\n cd <your_destination>",
main: box |args: &[String], shell: &mut Shell| {
shell.directory_stack.cd(args);
},
});
commands.insert("dirs",
Command {
name: "dirs",
help: "Make a sleep in the current session\n sleep \
<number_of_seconds>",
main: box |args: &[String], shell: &mut Shell| {
shell.directory_stack.dirs(args);
},
});
commands.insert("exit",
Command {
name: "exit",
help: "To exit the curent session",
main: box |args: &[String], _: &mut Shell| {
if let Some(status) = args.get(1) {
if let Ok(status) = status.parse::<i32>() {
process::exit(status);
}
}
// TODO should use exit status of previously run command, not 0
process::exit(0);
},
});
commands.insert("let",
Command {
name: "let",
help: "View, set or unset variables",
main: box |args: &[String], shell: &mut Shell| {
shell.variables.let_(args);
},
});
commands.insert("read",
Command {
name: "read",
help: "To read some variables\n read <my_variable>",
main: box |args: &[String], shell: &mut Shell| {
shell.variables.read(args);
},
});
commands.insert("pushd",
Command {
name: "pushd",
help: "Make a sleep in the current session\n sleep \
<number_of_seconds>",
main: box |args: &[String], shell: &mut Shell| {
shell.directory_stack.pushd(args);
},
});
commands.insert("popd",
Command {
name: "popd",
help: "Make a sleep in the current session\n sleep \
<number_of_seconds>",
main: box |args: &[String], shell: &mut Shell| {
shell.directory_stack.popd(args);
},
});
commands.insert("history",
Command {
name: "history",
help: "Display all commands previously executed",
main: box |args: &[String], shell: &mut Shell| {
shell.history.history(args);
},
});
commands.insert("if",
Command {
name: "if",
help: "Conditionally execute code",
main: box |args: &[String], shell: &mut Shell| {
shell.flow_control.if_(args);
},
});
commands.insert("else",
Command {
name: "else",
help: "Execute code if a previous condition was false",
main: box |args: &[String], shell: &mut Shell| {
shell.flow_control.else_(args);
},
});
commands.insert("end",
Command {
name: "end",
help: "end a code block",
main: box |args: &[String], shell: &mut Shell| {
shell.flow_control.end(args);
},
});
commands.insert("for",
Command {
name: "for",
help: "Loop over something",
main: box |args: &[String], shell: &mut Shell| {
shell.flow_control.for_(args);
},
});
let command_helper: HashMap<&'static str, &'static str> = commands.iter()
.map(|(k, v)| {
(*k, v.help)
})
.collect();
commands.insert("help",
Command {
name: "help",
help: "Display a little helper for a given command\n help ls",
main: box move |args: &[String], _: &mut Shell| {
if let Some(command) = args.get(1) {
if command_helper.contains_key(command.as_str()) {
match command_helper.get(command.as_str()) {
Some(help) => println!("{}", help),
None => {
println!("Command helper not found [run 'help']...")
}
}
} else {
println!("Command helper not found [run 'help']...");
}
} else {
for (command, _help) in command_helper.iter() {
println!("{}", command);
}
}
},
});
commands
}
}
fn main() {
let commands = Command::map();
let mut shell = Shell::new();
for arg in env::args().skip(1) {
let mut command_list = String::new();
if let Ok(mut file) = File::open(&arg) {
if let Err(message) = file.read_to_string(&mut command_list) {
println!("{}: Failed to read {}", message, arg);
}
}
shell.on_command(&command_list, &commands);
return;
}
loop {
shell.print_prompt();
if let Some(command) = readln() {
let command = command.trim();
if !command.is_empty() {
shell.on_command(command, &commands);
}
} else {
break;
}
}
}