refactor: merging executables to save disk space (wip)

Cargo.toml

@@ -1,24 +1,24 @@
-[workspace]
+[package]
+name = "mutils"
+version = "0.1.0"
+edition = "2021"
 
-resolver = "2"
+[lib]
+name = "utils"
+path = "src/utils/lib.rs"
 
-members = [
-	"dmesg",
-	"fdisk",
-	"insmod",
-	"login",
-	"lsmod",
-	"mkfs",
-	"mount",
-	"nologin",
-	"powerctl",
-	"ps",
-	"rmmod",
-	"su",
-	"umount",
-	"usrgrp",
-	"utils",
-]
+[[bin]]
+name = "mutils"
+path = "src/main.rs"
+
+[[bin]]
+name = "mutils-suid"
+path = "src/main-suid.rs"
+
+[dependencies]
+argon2 = { version = "0.5.3", features = ["password-hash"] }
+libc = "0.2.155"
+rand_core = { version = "0.6.4", features = ["getrandom"] }
 
 [profile.release]
 panic = "abort"

dmesg/src/main.rs → src/dmesg.rs

@@ -1,14 +1,9 @@
 //! The `dmesg` command allows to print the kernel's logs.
 
-use std::env;
-
 /// The path to the kmsg device file.
 const KMSG_PATH: &str = "/dev/kmsg";
 
-fn main() {
-    let _args: Vec<String> = env::args().collect();
-    // TODO parse arguments
-
+pub fn main() {
     // TODO read non blocking from file
     // TODO for each line:
     // - split once with `;`

lsmod/src/main.rs → src/lsmod.rs

@@ -1,36 +1,28 @@
 //! The `lsmod` command allows to list loaded kernel modules.
 
+use crate::error;
 use std::fs::File;
 use std::io::BufRead;
 use std::io::BufReader;
-use std::process::exit;
 
 /// The path to the modules file.
 const MODULES_PATH: &str = "/proc/modules";
 
-fn main() {
-    let file = match File::open(MODULES_PATH) {
-        Ok(f) => f,
-        Err(e) => {
-            eprintln!("lsmod: cannot open `{MODULES_PATH}`: {e}");
-            exit(1);
-        }
-    };
-
+pub fn main() {
+    let file = File::open(MODULES_PATH).unwrap_or_else(|e| {
+        error("lsmod", format_args!("cannot open `{MODULES_PATH}`: {e}"));
+    });
     let reader = BufReader::new(file);
-
     println!("Name\tSize\tUsed by");
-
     for line in reader.lines() {
-        // TODO handle error
-        let mut split = line.as_ref().unwrap().split(' ');
-
+        let line = line.unwrap_or_else(|e| {
+            error("lsmod", e);
+        });
+        let mut split = line.split(' ');
         let name = split.next().unwrap();
         let size = split.next().unwrap();
         let use_count = split.next().unwrap();
         let used_by_list = split.next().unwrap();
-
-        // TODO padding
-        println!("{name}\t{size}\t{use_count}\t{used_by_list}");
+        println!("{name} {size}  {use_count} {used_by_list}");
     }
 }

src/main-suid.rs

@@ -0,0 +1,5 @@
+//! Main of all commands that **require** the SUID flag.
+
+fn main() {
+    // TODO
+}

src/main.rs

@@ -0,0 +1,57 @@
+//! Main of all commands that **do not require** the SUID flag.
+
+#![feature(option_get_or_insert_default)]
+
+mod dmesg;
+mod lsmod;
+mod mount;
+mod nologin;
+mod ps;
+
+use std::process::exit;
+use std::{env, fmt};
+
+/// Writes an error to stderr, then exits.
+fn error<M: fmt::Display>(bin: &str, msg: M) -> ! {
+    eprintln!("{bin}: error: {msg}");
+    exit(1);
+}
+
+fn main() {
+    let mut args = env::args_os();
+    let bin = args
+        .next()
+        .and_then(|s| s.into_string().ok())
+        .unwrap_or_else(|| {
+            error("mutils", "missing binary name");
+        });
+    match bin.as_str() {
+        "dmesg" => dmesg::main(),
+        "fdisk" => todo!(),
+        "insmod" => todo!(),
+        "lsmod" => lsmod::main(),
+        "rmmod" => todo!(),
+        bin @ ("mkfs" | "mkfs.ext2") => {
+            // TODO change default fs to `ext4` when implemented
+            let fs_name = bin.find(".").map(|i| &bin[(i + 1)..]).unwrap_or("ext2");
+            todo!()
+        }
+        "mount" => mount::main(args),
+        "umount" => todo!(),
+        "nologin" => nologin::main(),
+        "powerctl" => todo!(),
+        "halt" => todo!(),
+        "poweroff" => todo!(),
+        "reboot" => todo!(),
+        "shutdown" => todo!(),
+        "suspend" => todo!(),
+        "ps" => ps::main(),
+        "useradd" => todo!(),
+        "usermod" => todo!(),
+        "userdel" => todo!(),
+        "groupadd" => todo!(),
+        "groupmod" => todo!(),
+        "groupdel" => todo!(),
+        _ => error("mutils", "invalid binary name"),
+    }
+}