First version of findmnt

Author: Harshit933

Cargo.lock

@@ -35,6 +35,7 @@ feat_common_core = [
   "mountpoint",
   "rev",
   "setsid",
+  "findmnt",
 ]
 
 [workspace.dependencies]
@@ -76,6 +77,7 @@ lsmem = { optional = true, version = "0.0.1", package = "uu_lsmem", path = "src/
 mountpoint = { optional = true, version = "0.0.1", package = "uu_mountpoint", path = "src/uu/mountpoint" }
 rev = { optional = true, version = "0.0.1", package = "uu_rev", path = "src/uu/rev" }
 setsid = { optional = true, version = "0.0.1", package = "uu_setsid", path ="src/uu/setsid" }
+findmnt = { optional = true, version = "0.0.1", package = "uu_findmnt", path = "src/uu/findmnt" }
 
 [dev-dependencies]
 # dmesg test require fixed-boot-time feature turned on.

Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "uu_findmnt"
+version = "0.0.1"
+edition = "2021"
+
+[lib]
+path = "src/findmnt.rs"
+
+[[bin]]
+name = "findmnt"
+path = "src/main.rs"
+
+[dependencies]
+tabled = { workspace = true }
+uucore = { workspace = true }
+clap = { workspace = true }

src/uu/findmnt/Cargo.toml

@@ -0,0 +1,7 @@
+# findmnt
+
+```
+findmnt [options]
+```
+
+findmnt will list all mounted filesytems or search for a filesystem. The findmnt command is able to search in /etc/fstab, /etc/fstab.d, /etc/mtab or /proc/self/mountinfo. If device or mountpoint is not given, all filesystems are shown.

src/uu/findmnt/findmnt.md

@@ -0,0 +1,189 @@
+use core::fmt;
+use std::fs;
+
+use clap::{crate_version, Command};
+use tabled::{settings::Style, Table, Tabled};
+use uucore::{error::UResult, help_about};
+
+#[uucore::main]
+pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+    let _matches: clap::ArgMatches = uu_app().try_get_matches_from(args)?;
+
+    // By default findmnt reads /proc/self/mountinfo
+    let mut res = Findmnt::new(MOUNTINFO_DIR);
+    res.form_nodes();
+    res.print_table();
+    Ok(())
+}
+
+pub static MOUNTINFO_DIR: &str = "/proc/self/mountinfo";
+pub static ABOUT: &str = help_about!("findmnt.md");
+
+pub fn uu_app() -> Command {
+    Command::new(uucore::util_name())
+        .version(crate_version!())
+        .about(ABOUT)
+}
+
+#[derive(Debug, Clone)]
+pub struct Findmnt<'a> {
+    pub nodes_vec: Vec<Node>,
+    file_name: &'a str,
+}
+
+impl<'a> Findmnt<'a> {
+    pub fn new(file_name: &str) -> Findmnt {
+        Findmnt {
+            file_name,
+            nodes_vec: Vec::<Node>::new(),
+        }
+    }
+
+    pub fn form_nodes(&mut self) {
+        let res = fs::read_to_string(self.file_name).unwrap();
+        let lines = res.lines();
+        let mut unsorted_vec = Vec::<Node>::new();
+
+        for line in lines {
+            let res = Node::parse(line);
+            unsorted_vec.push(res);
+        }
+
+        self.nodes_vec = unsorted_vec;
+        // /, /proc, /sys, /dev, /run, /tmp, /boot
+        // Sort the vec according to this
+        self.sort_nodes();
+    }
+
+    pub fn print_table(&self) {
+        let mut table = Table::new(self.nodes_vec.clone());
+        table.with(Style::empty());
+        print!("{}", table)
+    }
+
+    fn sort_nodes(&mut self) {
+        let unsorted_vec = self.nodes_vec.clone();
+        let mut sorted_vec = Vec::new();
+
+        // "/"
+        // This should always give one element
+        let res = unsorted_vec
+            .iter()
+            .find(|node| node.target == Types::ROOT.to_string());
+        sorted_vec.push(res.unwrap().clone());
+
+        // "proc"
+        sorted_vec.extend(self.filter(Types::PROC));
+
+        // "/sys"
+        sorted_vec.extend(self.filter(Types::SYS));
+
+        // "/dev"
+        sorted_vec.extend(self.filter(Types::DEV));
+
+        // "/run"
+        sorted_vec.extend(self.filter(Types::RUN));
+
+        // "/tmp"
+        sorted_vec.extend(self.filter(Types::TMP));
+
+        // "/boot"
+        sorted_vec.extend(self.filter(Types::BOOT));
+
+        self.nodes_vec = sorted_vec;
+    }
+
+    fn filter(&self, pattern: Types) -> Vec<Node> {
+        let mut temp_vec = Vec::<Node>::new();
+        let _ = self.filter_with_pattern(pattern).iter().for_each(|node| {
+            temp_vec.push(node.clone());
+        });
+        temp_vec
+    }
+
+    fn filter_with_pattern(&self, pattern: Types) -> Vec<Node> {
+        self.nodes_vec
+            .iter()
+            .filter(|node| node.target.starts_with(&pattern.to_string()))
+            .cloned()
+            .collect()
+    }
+}
+
+// Different types for a particular node
+#[derive(Debug, Clone)]
+pub enum Types {
+    ROOT,
+    PROC,
+    SYS,
+    DEV,
+    RUN,
+    TMP,
+    BOOT,
+}
+
+impl fmt::Display for Types {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Types::ROOT => write!(f, "{}", "/"),
+            Types::PROC => write!(f, "{}", "/proc"),
+            Types::SYS => write!(f, "{}", "/sys"),
+            Types::DEV => write!(f, "{}", "/dev"),
+            Types::RUN => write!(f, "{}", "/run"),
+            Types::TMP => write!(f, "{}", "/tmp"),
+            Types::BOOT => write!(f, "{}", "/boot"),
+        }
+    }
+}
+
+// Represents each row for the table
+#[derive(Debug, Clone, Tabled)]
+pub struct Node {
+    target: String,
+    source: String,
+    fstype: String,
+    options: String,
+}
+
+impl Node {
+    fn new(target: String, source: String, fstype: String, options: String) -> Node {
+        Node {
+            target,
+            source,
+            fstype,
+            options,
+        }
+    }
+
+    pub fn filter_with_pattern(node_vec: &Vec<Node>, pattern: Types) -> Vec<Node> {
+        node_vec
+            .iter()
+            .filter(|node| node.target.starts_with(&pattern.to_string()))
+            .cloned()
+            .collect()
+    }
+
+    // This is the main function that parses the default /proc/self/mountinfo
+    pub fn parse(line: &str) -> Self {
+        let (_, rest) = line.split_once("/").unwrap();
+        let (target, rest) = rest.trim().split_once(" ").unwrap();
+        let (options, rest) = rest.trim().split_once(" ").unwrap();
+        let (_, rest) = rest.trim().split_once("-").unwrap();
+        let (fstype, rest) = rest.trim().split_once(" ").unwrap();
+        let (source, rest) = rest.trim().split_once(" ").unwrap();
+        let options_added = if let Some(_) = rest.split_once("rw") {
+            rest.split_once("rw").unwrap().1
+        } else {
+            rest
+        };
+
+        let final_options = options.to_owned() + options_added;
+
+        Self::new(
+            target.to_string(),
+            source.to_string(),
+            fstype.to_string(),
+            final_options,
+        )
+    }
+}

src/uu/findmnt/src/findmnt.rs

@@ -0,0 +1 @@
+uucore::bin!(uu_findmnt);