From 4b36064303d26b0c60698024ddfa5512cfedee3e Mon Sep 17 00:00:00 2001
From: yuankunzhang <fmcocoa@gmail.com>
Date: Sun, 31 Aug 2025 21:31:51 +0800
Subject: [PATCH] who: honor locale settings

---
 src/uu/who/src/platform/unix.rs | 17 +++++++++++----
 tests/by-util/test_who.rs       | 27 +++++++++++++++++++++++-
 tests/uutests/src/lib/util.rs   | 37 ++++++++++++++++++++++++++++++++-
 3 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/src/uu/who/src/platform/unix.rs b/src/uu/who/src/platform/unix.rs
index d06f199b132..5266ce0ed47 100644
--- a/src/uu/who/src/platform/unix.rs
+++ b/src/uu/who/src/platform/unix.rs
@@ -163,11 +163,20 @@ fn idle_string<'a>(when: i64, boottime: i64) -> Cow<'a, str> {
 }
 
 fn time_string(ut: &UtmpxRecord) -> String {
-    // "%b %e %H:%M"
-    let time_format: Vec<time::format_description::FormatItem> =
+    let lc_time = std::env::var("LC_ALL")
+        .or_else(|_| std::env::var("LC_TIME"))
+        .or_else(|_| std::env::var("LANG"))
+        .unwrap_or_default();
+
+    let time_format: Vec<time::format_description::FormatItem> = if lc_time == "C" {
+        // "%b %e %H:%M"
         time::format_description::parse("[month repr:short] [day padding:space] [hour]:[minute]")
-            .unwrap();
-    ut.login_time().format(&time_format).unwrap() // LC_ALL=C
+            .unwrap()
+    } else {
+        // "%Y-%m-%d %H:%M"
+        time::format_description::parse("[year]-[month]-[day] [hour]:[minute]").unwrap()
+    };
+    ut.login_time().format(&time_format).unwrap()
 }
 
 #[inline]
diff --git a/tests/by-util/test_who.rs b/tests/by-util/test_who.rs
index 74475895cb0..d94a7b99a8f 100644
--- a/tests/by-util/test_who.rs
+++ b/tests/by-util/test_who.rs
@@ -7,7 +7,7 @@
 
 use uutests::new_ucmd;
 use uutests::unwrap_or_return;
-use uutests::util::{TestScenario, expected_result};
+use uutests::util::{TestScenario, expected_result, gnu_cmd_result};
 use uutests::util_name;
 #[test]
 fn test_invalid_arg() {
@@ -250,3 +250,28 @@ fn test_all() {
         ts.ucmd().arg(opt).succeeds().stdout_is(expected_stdout);
     }
 }
+
+#[cfg(unix)]
+#[test]
+#[ignore = "issue #3219"]
+fn test_locale() {
+    let ts = TestScenario::new(util_name!());
+
+    let expected_stdout =
+        unwrap_or_return!(gnu_cmd_result(&ts, &[], &[("LC_ALL", "C")])).stdout_move_str();
+    ts.ucmd()
+        .env("LC_ALL", "C")
+        .succeeds()
+        .stdout_is(&expected_stdout);
+
+    let expected_stdout =
+        unwrap_or_return!(gnu_cmd_result(&ts, &[], &[("LC_ALL", "en_US.UTF-8")])).stdout_move_str();
+    ts.ucmd()
+        .env("LC_ALL", "C")
+        .succeeds()
+        .stdout_str_check(|s| s != expected_stdout);
+    ts.ucmd()
+        .env("LC_ALL", "en_US.UTF-8")
+        .succeeds()
+        .stdout_is(&expected_stdout);
+}
diff --git a/tests/uutests/src/lib/util.rs b/tests/uutests/src/lib/util.rs
index 93b3fd7d98f..69e38bf952f 100644
--- a/tests/uutests/src/lib/util.rs
+++ b/tests/uutests/src/lib/util.rs
@@ -3003,6 +3003,11 @@ fn parse_coreutil_version(version_string: &str) -> f32 {
 /// If the `util_name` in `$PATH` doesn't include a coreutils version string,
 /// or the version is too low, this returns an error and the test should be skipped.
 ///
+/// Arguments:
+/// - `ts`: The test context.
+/// - `args`: Command-line variables applied to the command.
+/// - `envs`: Environment variables applied to the command invocation.
+///
 /// Example:
 ///
 /// ```no_run
@@ -3019,7 +3024,11 @@ fn parse_coreutil_version(version_string: &str) -> f32 {
 /// }
 ///```
 #[cfg(unix)]
-pub fn expected_result(ts: &TestScenario, args: &[&str]) -> std::result::Result<CmdResult, String> {
+pub fn gnu_cmd_result(
+    ts: &TestScenario,
+    args: &[&str],
+    envs: &[(&str, &str)],
+) -> std::result::Result<CmdResult, String> {
     let util_name = ts.util_name.as_str();
     println!("{}", check_coreutil_version(util_name, VERSION_MIN)?);
     let util_name = host_name_for(util_name);
@@ -3028,6 +3037,7 @@ pub fn expected_result(ts: &TestScenario, args: &[&str]) -> std::result::Result<
         .cmd(util_name.as_ref())
         .env("PATH", PATH)
         .envs(DEFAULT_ENV)
+        .envs(envs.iter().copied())
         .args(args)
         .run();
 
@@ -3056,6 +3066,31 @@ pub fn expected_result(ts: &TestScenario, args: &[&str]) -> std::result::Result<
     ))
 }
 
+/// This runs the GNU coreutils `util_name` binary in `$PATH` in order to
+/// dynamically gather reference values on the system.
+/// If the `util_name` in `$PATH` doesn't include a coreutils version string,
+/// or the version is too low, this returns an error and the test should be skipped.
+///
+/// Example:
+///
+/// ```no_run
+/// use uutests::util::*;
+/// #[test]
+/// fn test_xyz() {
+///     let ts = TestScenario::new(util_name!());
+///     let result = ts.ucmd().run();
+///     let exp_result = unwrap_or_return!(expected_result(&ts, &[]));
+///     result
+///         .stdout_is(exp_result.stdout_str())
+///         .stderr_is(exp_result.stderr_str())
+///         .code_is(exp_result.code());
+/// }
+///```
+#[cfg(unix)]
+pub fn expected_result(ts: &TestScenario, args: &[&str]) -> std::result::Result<CmdResult, String> {
+    gnu_cmd_result(ts, args, &[])
+}
+
 /// This is a convenience wrapper to run a ucmd with root permissions.
 /// It can be used to test programs when being root is needed
 /// This runs `sudo -E --non-interactive target/debug/coreutils util_name args`