Add last Utility (#65)

Cargo.toml

@@ -31,6 +31,7 @@ feat_common_core = [
   "lsmem",
   "ctrlaltdel",
   "rev",
+  "last"
 ]
 
 [workspace.dependencies]
@@ -50,6 +51,7 @@ rand = { version = "0.8", features = ["small_rng"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.122"
 tabled = "0.16.0"
+dns-lookup = "2.0.4"
 
 [dependencies]
 clap = { workspace = true }
@@ -58,6 +60,7 @@ clap_mangen = { workspace = true }
 uucore = { workspace = true }
 phf = { workspace = true }
 textwrap = { workspace = true }
+dns-lookup = { workspace = true }
 
 #
 lscpu = { optional = true, version = "0.0.1", package = "uu_lscpu", path = "src/uu/lscpu" }
@@ -65,6 +68,7 @@ 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" }
 ctrlaltdel = { optional = true, version = "0.0.1", package = "uu_ctrlaltdel", path = "src/uu/ctrlaltdel" }
 rev = { optional = true, version = "0.0.1", package = "uu_rev", path = "src/uu/rev" }
+last = { optional = true, version = "0.0.1", package = "uu_last", path = "src/uu/last" }
 
 [dev-dependencies]
 pretty_assertions = "1"

src/uu/last/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "uu_last"
+version = "0.0.1"
+edition = "2021"
+
+[lib]
+path = "src/last.rs"
+
+[dependencies]
+uucore = { workspace = true, features = ["utmpx"] }
+clap = { workspace = true}
+dns-lookup = { workspace = true }

src/uu/last/last.md

@@ -0,0 +1,8 @@
+# last
+
+```
+Usage:
+ [options] [<username>...] [<tty>...]
+```
+
+Show a listing of last logged in users.

src/uu/last/src/last.rs

@@ -0,0 +1,94 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+use clap::{crate_version, Arg, ArgAction, Command};
+use uucore::{format_usage, help_about, help_usage};
+
+mod platform;
+
+mod options {
+    pub const SYSTEM: &str = "system";
+    pub const HOSTLAST: &str = "hostlast";
+    pub const NO_HOST: &str = "nohostname";
+    pub const LIMIT: &str = "limit";
+    pub const DNS: &str = "dns";
+    pub const TIME_FORMAT: &str = "time-format";
+    pub const USER_TTY: &str = "username";
+    pub const FILE: &str = "file";
+}
+
+const ABOUT: &str = help_about!("last.md");
+const USAGE: &str = help_usage!("last.md");
+
+#[uucore::main]
+use platform::uumain;
+
+pub fn uu_app() -> Command {
+    Command::new(uucore::util_name())
+        .version(crate_version!())
+        .about(ABOUT)
+        .override_usage(format_usage(USAGE))
+        .infer_long_args(true)
+        .arg(
+            Arg::new(options::FILE)
+                .short('f')
+                .long("file")
+                .action(ArgAction::Set)
+                .default_value("/var/log/wtmp")
+                .help("use a specific file instead of /var/log/wtmp")
+                .required(false),
+        )
+        .arg(
+            Arg::new(options::SYSTEM)
+                .short('x')
+                .long(options::SYSTEM)
+                .action(ArgAction::SetTrue)
+                .required(false)
+                .help("display system shutdown entries and run level changes"),
+        )
+        .arg(
+            Arg::new(options::DNS)
+                .short('d')
+                .long(options::DNS)
+                .action(ArgAction::SetTrue)
+                .required(false)
+                .help("translate the IP number back into a hostname"),
+        )
+        .arg(
+            Arg::new(options::HOSTLAST)
+                .short('a')
+                .long(options::HOSTLAST)
+                .action(ArgAction::SetTrue)
+                .required(false)
+                .help("display hostnames in the last column"),
+        )
+        .arg(
+            Arg::new(options::NO_HOST)
+                .short('R')
+                .long(options::NO_HOST)
+                .action(ArgAction::SetTrue)
+                .required(false)
+                .help("don't display the hostname field"),
+        )
+        .arg(
+            Arg::new(options::LIMIT)
+                .short('n')
+                .long(options::LIMIT)
+                .action(ArgAction::Set)
+                .required(false)
+                .help("how many lines to show")
+                .value_parser(clap::value_parser!(i32))
+                .allow_negative_numbers(true),
+        )
+        .arg(
+            Arg::new(options::TIME_FORMAT)
+                .long(options::TIME_FORMAT)
+                .action(ArgAction::Set)
+                .required(false)
+                .help("show timestamps in the specified <format>: notime|short|full|iso")
+                .default_value("short"),
+        )
+        .arg(Arg::new(options::USER_TTY).action(ArgAction::Append))
+}

src/uu/last/src/main.rs

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

src/uu/last/src/platform/mod.rs

@@ -0,0 +1,19 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+#[cfg(unix)]
+mod unix;
+#[cfg(unix)]
+pub use self::unix::*;
+
+#[cfg(target_os = "openbsd")]
+mod openbsd;
+#[cfg(target_os = "openbsd")]
+pub use self::openbsd::*;
+
+#[cfg(windows)]
+mod windows;
+#[cfg(windows)]
+pub use self::windows::*;

src/uu/last/src/platform/openbsd.rs

@@ -0,0 +1,17 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+// Specific implementation for OpenBSD: tool unsupported (utmpx not supported)
+
+use crate::uu_app;
+
+use uucore::error::UResult;
+
+pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+    let _matches = uu_app().try_get_matches_from(args)?;
+
+    println!("unsupported command on OpenBSD");
+    Ok(())
+}

src/uu/last/src/platform/windows.rs

@@ -0,0 +1,17 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+// Specific implementation for Windows: tool unsupported (utmpx not supported)
+
+use crate::uu_app;
+
+use uucore::error::UResult;
+
+pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+    let _matches = uu_app().try_get_matches_from(args)?;
+
+    println!("unsupported command on Windows");
+    Ok(())
+}

tests/by-util/test_last.rs

@@ -0,0 +1,111 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+// spell-checker:ignore (words) symdir somefakedir
+
+use crate::common::util::TestScenario;
+
+use regex::Regex;
+use std::fs;
+use std::io::Write;
+
+#[test]
+#[cfg(unix)]
+fn test_invalid_arg() {
+    new_ucmd!().arg("--definitely-invalid").fails().code_is(1);
+}
+
+#[test]
+#[cfg(unix)]
+fn test_last() {
+    let regex = Regex::new("still running|still logged in").unwrap();
+    TestScenario::new(util_name!())
+        .ucmd()
+        .succeeds()
+        .stdout_matches(&regex);
+}
+
+#[test]
+#[cfg(unix)]
+fn test_limit_arg() {
+    let line_check = |input: &str| input.lines().count() == 3;
+    new_ucmd!()
+        .arg("--limit=1")
+        .succeeds()
+        .stdout_str_check(line_check);
+}
+
+#[test]
+// The -x flag generally adds two rows "shutdown" and "runlevel"
+// "shutdown" cannot be checked for since not every machine will have shutdown
+// "runlevel" only makes sense for Linux systems, so only Linux is included for
+// this test.
+#[cfg(target_os = "linux")]
+#[ignore = "fails on Arch Linux"]
+fn test_system_arg() {
+    new_ucmd!().arg("-x").succeeds().stdout_contains("runlevel");
+}
+
+#[test]
+#[cfg(unix)]
+fn test_timestamp_format_no_time() {
+    let regex = Regex::new(" [0-9][0-9]:[0-9][0-9] ").unwrap();
+    new_ucmd!()
+        .arg("--time-format=notime")
+        .succeeds()
+        .stdout_does_not_match(&regex);
+}
+
+#[test]
+#[cfg(unix)]
+fn test_timestamp_format_short() {
+    let regex = Regex::new(" [0-9][0-9]:[0-9][0-9] ").unwrap();
+    new_ucmd!()
+        .arg("--time-format=short")
+        .succeeds()
+        .stdout_matches(&regex);
+}
+
+#[test]
+#[cfg(unix)]
+fn test_timestamp_format_full() {
+    let regex = Regex::new(" [0-9][0-9]:[0-9][0-9]:[0-9][0-9] ").unwrap();
+    new_ucmd!()
+        .arg("--time-format=full")
+        .succeeds()
+        .stdout_matches(&regex);
+}
+
+// 2024-07-11T19:30:44+08:00
+#[test]
+#[cfg(unix)]
+fn test_timestamp_format_iso() {
+    let regex =
+        Regex::new(" [0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]T[0-9][0-9]:[0-9][0-9]:[0-9][0-9]")
+            .unwrap();
+    new_ucmd!()
+        .arg("--time-format=iso")
+        .succeeds()
+        .stdout_matches(&regex);
+}
+
+#[test]
+#[cfg(unix)]
+fn test_short_invalid_utmp_file() {
+    let filepath = "/tmp/testfile";
+    let testfile = fs::File::create(filepath);
+    // Random bytes
+    let data: Vec<u8> = vec![
+        4, 5, 6, 16, 8, 13, 2, 12, 5, 3, 11, 5, 1, 13, 1, 1, 0, 9, 5, 5, 2, 8, 4,
+    ];
+    let _ = testfile.unwrap().write_all(&data);
+
+    let regex = Regex::new(r"\n\S*\sbegins\s*(Mon|Tue|Wed|Thu|Fri|Sat|Sun)\s*(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s*[0-9][0-9]?\s*[0-9][0-9]:[0-9][0-9]:[0-9][0-9]\s*[0-9]*")
+            .unwrap();
+
+    new_ucmd!()
+        .arg(format!("--file={filepath}"))
+        .succeeds()
+        .stdout_matches(&regex);
+}

tests/tests.rs

@@ -24,3 +24,7 @@ mod test_ctrlaltdel;
 #[cfg(feature = "rev")]
 #[path = "by-util/test_rev.rs"]
 mod test_rev;
+
+#[cfg(feature = "last")]
+#[path = "by-util/test_last.rs"]
+mod test_last;