commit c5f5b2a8688324cc7ed488c4e4bd9a1ee446ee6f
Author: William Brawner <me@wbrawner.com>
Date:   Sat Jul 23 22:14:31 2022 -0600

    Initial commit
    
    This is still experimental, though for now I've been able to implement a
    few commands:
    
    - cd:    changes the current working directory of the agent
    - ls:    lists the directories and files in the current working directory
    - ping:  responds with "pong"
    - pwd:   prints the current working directory
    - shell: executes an arbitrary command on the host

diff --git a/.gitignore b/.gitignore
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index 0000000..ea8c4bf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/Cargo.lock b/Cargo.lock
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--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "gsm-agent"
+version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..bff75c2
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "gsm-agent"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/src/.main.rs.swp b/src/.main.rs.swp
new file mode 100644
index 0000000..b9728cb
Binary files /dev/null and b/src/.main.rs.swp differ
diff --git a/src/main.rs b/src/main.rs
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index 0000000..d4a9100
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,78 @@
+use std::cmp::Ordering;
+use std::env;
+use std::fs;
+use std::fs::DirEntry;
+use std::io::Read;
+use std::io::Write;
+use std::net::TcpListener;
+use std::net::TcpStream;
+use std::path::Path;
+use std::process::Command;
+
+fn main() {
+    let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
+    for stream in listener.incoming() {
+        let stream = stream.unwrap();
+        handle_connection(stream);
+    }
+}
+
+fn cwd() -> String {
+    env::current_dir().unwrap().to_string_lossy().to_string()
+}
+
+fn handle_connection(mut stream: TcpStream) {
+    let mut buffer = [0; 1024];
+    stream.read(&mut buffer).unwrap();
+    let mut request: &str = &String::from_utf8(buffer.to_vec()).unwrap();
+    request = request.trim();
+    let trim_chars = [' ', '\n', '\0'];
+    request = request.trim_matches(&trim_chars[..]);
+    let mut command_iter = request.split_whitespace();
+    let command = command_iter.next().unwrap();
+    let response: String = match command {
+        "cd" => {
+            let path = Path::new(command_iter.next().unwrap());
+            env::set_current_dir(path).unwrap();
+            cwd()
+        }
+        "ls" => {
+            let mut files: Vec<String> = Vec::new();
+            let mut paths: Vec<DirEntry> =
+                fs::read_dir(cwd()).unwrap().map(|r| r.unwrap()).collect();
+            paths.sort_by(|a, b| {
+                let a_is_dir = a.file_type().unwrap().is_dir();
+                let b_is_dir = b.file_type().unwrap().is_dir();
+                if a_is_dir && !b_is_dir {
+                    Ordering::Less
+                } else if !a_is_dir && b_is_dir {
+                    Ordering::Greater
+                } else {
+                    a.file_name().cmp(&b.file_name())
+                }
+            });
+            for file in paths {
+                files.push(file.file_name().into_string().unwrap());
+            }
+            files.join("\n")
+        }
+        "ping" => String::from("pong"),
+        "pwd" => cwd(),
+        "shell" => String::from_utf8(
+            Command::new(command_iter.next().unwrap())
+                .args(command_iter)
+                .output()
+                .unwrap()
+                .stdout,
+        )
+        .unwrap(),
+        _ => {
+            format!(
+                "unknown command: {:?}",
+                request.split_whitespace().next().unwrap_or("")
+            )
+        }
+    };
+    stream.write(format!("{}\n", response).as_bytes()).unwrap();
+    stream.flush().unwrap();
+}