refactor: flatten package managers into plain functions

README.md

@@ -7,13 +7,6 @@ However, maintaining clean code is also a priority.. <br>
 <img width="40%" alt="image" src="https://github.com/user-attachments/assets/85c006b2-c604-4346-b24a-8a515a1b3fd2" />
 
 
-### supports the following package managers
-
-- xbps ( [Void Linux](https://voidlinux.org/) )
-- apk ( [Alpine Linux](https://wiki.alpinelinux.org/wiki/Main_Page) )
-- pacman ( [Arch Linux](https://archlinux.org/) )
-- emerge ( [Gentoo Linux](https://www.gentoo.org/) )
-
 btw, i'll be happy if somebody send some cool ascii cat arts in issues :point_right::point_left:
 
 ### installation

src/main.rs

@@ -1,8 +1,8 @@
 mod host;
 mod memory;
-mod package_managers;
+mod packages;
 mod uptime;
-use crate::{host::get_host, package_managers::PackageManagers};
+use crate::host::get_host;
 use colored::*;
 
 #[cfg(not(unix))]
@@ -27,10 +27,7 @@ fn main() {
         host = get_host().unwrap_or("Unknown".to_owned()),
         uptime = uptime::get().unwrap_or_default(),
         memory = memory::get().unwrap_or_default(),
-        pkgs = PackageManagers::new()
-            .count_pkgs_by_distro()
-            .expect("Failed to get package manager for this distro !")
-            .expect("Failed to count packages in this distro !"),
+        pkgs = packages::get().unwrap_or("Unknown".to_owned()),
         os_field = wrap_field("os"),
         host_field = wrap_field("host"),
         memory_field = wrap_field("memory"),

src/packages/apk.rs

@@ -0,0 +1,9 @@
+use std::io;
+
+use super::read_lines;
+
+pub fn count() -> io::Result<u64> {
+    Ok(read_lines("/lib/apk/db/installed")?
+        .filter(|line| line.starts_with("P:"))
+        .count() as u64)
+}

src/packages/emerge.rs

@@ -0,0 +1,9 @@
+use std::{fs, io};
+
+pub fn count() -> io::Result<u64> {
+    Ok(fs::read_dir("/var/db/pkg")?
+        .flatten()
+        .filter(|entry| entry.metadata().is_ok_and(|v| v.is_dir()))
+        .flat_map(|category| fs::read_dir(category.path()).map(|v| v.count() as u64))
+        .sum())
+}

src/packages/mod.rs

@@ -0,0 +1,47 @@
+mod apk;
+mod emerge;
+mod pacman;
+mod xbps;
+
+use std::{
+    fs::File,
+    io::{self, BufRead, BufReader},
+    path::Path,
+};
+
+type Count = fn() -> io::Result<u64>;
+
+const MANAGERS: [(&str, Count); 4] = [
+    ("xbps", xbps::count),
+    ("apk", apk::count),
+    ("pacman", pacman::count),
+    ("emerge", emerge::count),
+];
+
+// Counts installed packages of every package manager found on the system.
+// A single manager is shown as just the count, several as "xbps(632), apk(251)".
+pub fn get() -> io::Result<String> {
+    let counts: Vec<_> = MANAGERS
+        .iter()
+        .filter_map(|(name, count)| count().ok().map(|count| (name, count)))
+        .collect();
+
+    match counts.as_slice() {
+        [] => Err(io::Error::new(
+            io::ErrorKind::NotFound,
+            "no supported package manager found",
+        )),
+        [(_, count)] => Ok(count.to_string()),
+        _ => Ok(counts
+            .iter()
+            .map(|(name, count)| format!("{name}({count})"))
+            .collect::<Vec<_>>()
+            .join(", ")),
+    }
+}
+
+fn read_lines(path: impl AsRef<Path>) -> io::Result<impl Iterator<Item = String>> {
+    Ok(BufReader::new(File::open(path)?)
+        .lines()
+        .map_while(Result::ok))
+}

src/packages/pacman.rs

@@ -0,0 +1,10 @@
+use std::{fs, io};
+
+// Every installed package is a "<name>-<version>-<rel>" directory;
+// the only other entry is the ALPM_DB_VERSION file.
+pub fn count() -> io::Result<u64> {
+    Ok(fs::read_dir("/var/lib/pacman/local")?
+        .flatten()
+        .filter(|entry| entry.file_type().is_ok_and(|v| v.is_dir()))
+        .count() as u64)
+}

src/packages/xbps.rs

@@ -0,0 +1,14 @@
+use std::{fs, io, os::unix::ffi::OsStrExt};
+
+use super::read_lines;
+
+pub fn count() -> io::Result<u64> {
+    let pkgdb = fs::read_dir("/var/db/xbps")?
+        .flatten()
+        .find(|entry| entry.file_name().as_bytes().starts_with(b"pkgdb-"))
+        .ok_or_else(|| io::Error::new(io::ErrorKind::NotFound, "xbps pkgdb not found"))?;
+
+    Ok(read_lines(pkgdb.path())?
+        .filter(|line| line.contains("<key>repository</key>"))
+        .count() as u64)
+}