users: support OpenBS using utmp

OpenBSD uses the original utmp file format so the general `users` does not
work there. By using the `utmp-classic` lib, we cna process the current users
on the system from the /var/run/utmp and show the list.

fixes #5665

Cargo.lock

@@ -2449,6 +2449,30 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
 
+[[package]]
+name = "utmp-classic"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e24c654e19afaa6b8f3877ece5d3bed849c2719c56f6752b18ca7da4fcc6e85a"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "thiserror",
+ "time",
+ "utmp-classic-raw",
+ "zerocopy",
+]
+
+[[package]]
+name = "utmp-classic-raw"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22c226537a3d6e01c440c1926ca0256dbee2d19b2229ede6fc4863a6493dd831"
+dependencies = [
+ "cfg-if",
+ "zerocopy",
+]
+
 [[package]]
 name = "uu_arch"
 version = "0.0.27"
@@ -3390,6 +3414,7 @@ name = "uu_users"
 version = "0.0.27"
 dependencies = [
  "clap",
+ "utmp-classic",
  "uucore",
 ]
 
@@ -3897,18 +3922,19 @@ checksum = "2a599daf1b507819c1121f0bf87fa37eb19daac6aff3aefefd4e6e2e0f2020fc"
 
 [[package]]
 name = "zerocopy"
-version = "0.7.33"
+version = "0.7.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "087eca3c1eaf8c47b94d02790dd086cd594b912d2043d4de4bfdd466b3befb7c"
+checksum = "ae87e3fcd617500e5d106f0380cf7b77f3c6092aae37191433159dda23cfb087"
 dependencies = [
+ "byteorder",
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.7.33"
+version = "0.7.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f4b6c273f496d8fd4eaf18853e6b448760225dc030ff2c485a786859aea6393"
+checksum = "15e934569e47891f7d9411f1a451d947a60e000ab3bd24fbb970f000387d1b3b"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -330,6 +330,7 @@ time = { version = "0.3.36" }
 unicode-segmentation = "1.11.0"
 unicode-width = "0.1.12"
 utf-8 = "0.7.6"
+utmp-classic = "0.1.6"
 walkdir = "2.5"
 winapi-util = "0.1.8"
 windows-sys = { version = "0.48.0", default-features = false }

src/uu/users/Cargo.toml

@@ -18,6 +18,9 @@ path = "src/users.rs"
 clap = { workspace = true }
 uucore = { workspace = true, features = ["utmpx"] }
 
+[target.'cfg(target_os = "openbsd")'.dependencies]
+utmp-classic = { workspace = true }
+
 [[bin]]
 name = "users"
 path = "src/main.rs"

src/uu/users/src/platform/mod.rs

@@ -1,14 +0,0 @@
-// This file is part of the uutils coreutils package.
-//
-// For the full copyright and license information, please view the LICENSE
-// file that was distributed with this source code.
-
-#[cfg(not(target_os = "openbsd"))]
-mod unix;
-#[cfg(not(target_os = "openbsd"))]
-pub use self::unix::*;
-
-#[cfg(target_os = "openbsd")]
-mod openbsd;
-#[cfg(target_os = "openbsd")]
-pub use self::openbsd::*;

src/uu/users/src/platform/openbsd.rs

@@ -1,17 +0,0 @@
-// This file is part of the uutils coreutils 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/users/src/platform/unix.rs

@@ -1,53 +0,0 @@
-// This file is part of the uutils coreutils package.
-//
-// For the full copyright and license information, please view the LICENSE
-// file that was distributed with this source code.
-
-// spell-checker:ignore (paths) wtmp
-
-use crate::uu_app;
-
-use std::ffi::OsString;
-use std::path::Path;
-
-use uucore::error::UResult;
-use uucore::utmpx::{self, Utmpx};
-
-static ARG_FILES: &str = "files";
-
-fn get_long_usage() -> String {
-    format!(
-        "Output who is currently logged in according to FILE.
-If FILE is not specified, use {}.  /var/log/wtmp as FILE is common.",
-        utmpx::DEFAULT_FILE
-    )
-}
-
-pub fn uumain(args: impl uucore::Args) -> UResult<()> {
-    let matches = uu_app()
-        .after_help(get_long_usage())
-        .try_get_matches_from(args)?;
-
-    let files: Vec<&Path> = matches
-        .get_many::<OsString>(ARG_FILES)
-        .map(|v| v.map(AsRef::as_ref).collect())
-        .unwrap_or_default();
-
-    let filename = if files.is_empty() {
-        utmpx::DEFAULT_FILE.as_ref()
-    } else {
-        files[0]
-    };
-
-    let mut users = Utmpx::iter_all_records_from(filename)
-        .filter(Utmpx::is_user_process)
-        .map(|ut| ut.user())
-        .collect::<Vec<_>>();
-
-    if !users.is_empty() {
-        users.sort();
-        println!("{}", users.join(" "));
-    }
-
-    Ok(())
-}

src/uu/users/src/users.rs

@@ -5,19 +5,97 @@
 
 // spell-checker:ignore (paths) wtmp
 
+use std::ffi::OsString;
+use std::path::Path;
+
 use clap::builder::ValueParser;
 use clap::{crate_version, Arg, Command};
+use uucore::error::UResult;
 use uucore::{format_usage, help_about, help_usage};
 
-mod platform;
+#[cfg(target_os = "openbsd")]
+use utmp_classic::{parse_from_path, UtmpEntry};
+#[cfg(not(target_os = "openbsd"))]
+use uucore::utmpx::{self, Utmpx};
 
 const ABOUT: &str = help_about!("users.md");
 const USAGE: &str = help_usage!("users.md");
 
+#[cfg(target_os = "openbsd")]
+const OPENBSD_UTMP_FILE: &str = "/var/run/utmp";
+
 static ARG_FILES: &str = "files";
 
+fn get_long_usage() -> String {
+    #[cfg(not(target_os = "openbsd"))]
+    let default_path: &str = utmpx::DEFAULT_FILE;
+    #[cfg(target_os = "openbsd")]
+    let default_path: &str = OPENBSD_UTMP_FILE;
+    format!(
+        "Output who is currently logged in according to FILE.
+If FILE is not specified, use {}.  /var/log/wtmp as FILE is common.",
+        default_path
+    )
+}
+
 #[uucore::main]
-use platform::uumain;
+pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+    let matches = uu_app()
+        .after_help(get_long_usage())
+        .try_get_matches_from(args)?;
+
+    let files: Vec<&Path> = matches
+        .get_many::<OsString>(ARG_FILES)
+        .map(|v| v.map(AsRef::as_ref).collect())
+        .unwrap_or_default();
+
+    let mut users: Vec<String>;
+
+    // OpenBSD uses the Unix version 1 UTMP, all other Unixes use the newer UTMPX
+    #[cfg(target_os = "openbsd")]
+    {
+        let filename = if files.is_empty() {
+            Path::new(OPENBSD_UTMP_FILE)
+        } else {
+            files[0]
+        };
+        let entries = parse_from_path(&filename).unwrap_or(Vec::new());
+        users = Vec::new();
+        for entry in entries {
+            if let UtmpEntry::UTMP {
+                line: _,
+                user,
+                host: _,
+                time: _,
+            } = entry
+            {
+                if !user.is_empty() {
+                    users.push(user);
+                }
+            }
+        }
+    };
+    #[cfg(not(target_os = "openbsd"))]
+    {
+        let filename = if files.is_empty() {
+            utmpx::DEFAULT_FILE.as_ref()
+        } else {
+            files[0]
+        };
+
+        users = Utmpx::iter_all_records_from(filename)
+            .filter(Utmpx::is_user_process)
+            .map(|ut| ut.user())
+            .collect::<Vec<_>>();
+    };
+
+    if !users.is_empty() {
+        users.sort();
+        println!("{}", users.join(" "));
+    }
+
+    Ok(())
+}
 
 pub fn uu_app() -> Command {
     Command::new(uucore::util_name())

tests/by-util/test_users.rs

@@ -31,3 +31,12 @@ fn test_users_check_name() {
 
     new_ucmd!().succeeds().stdout_is(&expected);
 }
+
+#[test]
+#[cfg(target_os = "openbsd")]
+fn test_users_check_name_openbsd() {
+    new_ucmd!()
+        .args(&["openbsd_utmp"])
+        .run()
+        .stdout_contains("test");
+}