Add open-file option

Todo: This is absolutely atrocious code. Fix it.

src/main.rs

@@ -1,3 +1,5 @@
+#![allow(static_mut_refs)]
+
 use chrono::Local;
 use libc::kill;
 use nix::poll::{PollFd, PollFlags, PollTimeout, poll};
@@ -13,6 +15,7 @@ use std::ptr;
 
 static mut USE_KERNEL_ORDERING: bool = false;
 static mut PLAIN_MODE: bool = false;
+static mut OUT_FILE: Mutex<Option<Box<dyn Write>>> = Mutex::new(Option::None);
 
 #[derive(Debug, Default)]
 struct Ptys {
@@ -43,7 +46,15 @@ fn handle_data(mut stream: StdioStream) -> Result<(), bool> {
         Ok(n) => {
             let bufc = &buf[..n];
             if unsafe {PLAIN_MODE} {
-                std::io::stdout().write_all(bufc).unwrap();
+                if unsafe{OUT_FILE.get_mut().unwrap().is_none()} {
+                    std::io::stdout().write_all(bufc).unwrap();
+                } else {
+                    unsafe {
+                        OUT_FILE.lock().unwrap().as_mut().map(|f| {
+                            f.write_all(bufc).unwrap();
+                        });
+                    };
+                }
             } else {
                 for c in bufc {
                     stream.buffer.push(*c);
@@ -63,8 +74,22 @@ fn handle_data(mut stream: StdioStream) -> Result<(), bool> {
                                 }
                             };
                         let now = Local::now().format(&format).to_string();
-                        std::io::stdout().write_all(now.as_bytes()).unwrap();
+                        if unsafe{OUT_FILE.lock().unwrap().is_none()} {
-                        std::io::stdout().write_all(&stream.buffer).unwrap();
+                            let mut data: Vec<u8> = Vec::new();
+                            data.extend(now.as_bytes());
+                            data.extend_from_slice(&stream.buffer);
+                            std::io::stdout().write_all(&data).unwrap();
+                        } else {
+                            unsafe {
+                                OUT_FILE.lock().unwrap().as_mut().map(|f| {
+                                    let mut data: Vec<u8> = Vec::new();
+                                    data.extend(now.as_bytes());
+                                    data.extend_from_slice(&stream.buffer);
+                                    //std::io::stdout().write_all(data.as_slice()).unwrap();
+                                    f.write_all(&data).unwrap();
+                                });
+                            };
+                        }
                         stream.buffer.clear();
                     }
                 }
@@ -130,6 +155,7 @@ fn handle_poll(
     }
 }
 
+#[allow(unreachable_code)]
 fn spawn_child(ptys: &Ptys, user_cmd: String) {
     let cmd = CString::new("/bin/bash").unwrap();
     let bcmd = user_cmd;
@@ -285,12 +311,14 @@ fn main_loop(child: Pid, ptys: &Ptys) {
 }
 
 use std::ffi::OsString;
+use std::sync::Mutex;
 
 #[derive(Debug)]
 struct Args {
     kernel_order: bool,
     plain: bool,
     command: String,
+    file: Option<File>,
 }
 
 fn parse_args() -> Args {
@@ -300,15 +328,22 @@ fn parse_args() -> Args {
     let mut kernel_order = false;
     let mut plain = false;
     let mut command_parts: Vec<OsString> = Vec::new();
+    let mut parsing_open_file = false;
+    let mut file: Option<File> = Option::None;
 
     while let Some(arg) = args.next() {
-        if arg == "--kernel-order" {
+        if parsing_open_file {
+            file = Option::from(File::options().write(true).open(&arg).expect(format!("Failed to open {}", &arg.to_str().unwrap()).as_str()));
+            parsing_open_file = false;
+        } else if arg == "--kernel-order" {
             kernel_order = true;
         } else if arg == "--plain" {
             plain = true;
         } else if arg == "-c" || arg == "--command" {
             command_parts.extend(args);
             break;
+        } else if arg == "--open-file" {
+            parsing_open_file = true;
         } else {
             command_parts.push(arg);
             command_parts.extend(args);
@@ -316,6 +351,11 @@ fn parse_args() -> Args {
         }
     }
 
+    if !kernel_order && file.is_some() {
+        eprintln!("--open-file has to be used with --kernel-order");
+        std::process::exit(-1);
+    }
+
     let command = command_parts
         .into_iter()
         .map(|s| s.to_string_lossy().into_owned())
@@ -326,6 +366,7 @@ fn parse_args() -> Args {
         kernel_order,
         command,
         plain,
+        file,
     };
 
     parsed
@@ -337,9 +378,16 @@ fn main() {
     let cmd = args.command;
 
     unsafe { 
-        IS_TTY = libc::isatty(libc::STDOUT_FILENO) != 0;
         USE_KERNEL_ORDERING = args.kernel_order;
         PLAIN_MODE = args.plain;
+        let is_open_file = args.file.is_some();
+        args.file.map(|f| {
+            IS_TTY = libc::isatty((&f).as_raw_fd()) != 0;
+            OUT_FILE = Mutex::new(Option::from(Box::new(f) as Box<dyn Write>));
+        });
+        if !is_open_file {
+            IS_TTY = libc::isatty(libc::STDOUT_FILENO) != 0;
+        }
     };
     let mut ptys = Ptys::default();
     open_ptys(&mut ptys);