Fixing issues with users that have no active pid

.github/workflows/CICD.yml

@@ -739,22 +739,7 @@ jobs:
             # selinux and systemd headers needed to build tests
             sudo apt-get -y update
             sudo apt-get -y install libselinux1-dev libsystemd-dev
-            # pinky is a tool to show logged-in users from utmp, and gecos fields from /etc/passwd.
-            # In GitHub Action *nix VMs, no accounts log in, even the "runner" account that runs the commands, and "system boot" entry is missing.
-            # The account also has empty gecos fields.
-            # To work around these issues for pinky (and who) tests, we create a fake utmp file with a
-            # system boot entry and a login entry for the GH runner account.
-            FAKE_UTMP_2='[2] [00000] [~~  ] [reboot] [~   ] [6.0.0-test] [0.0.0.0] [2022-02-22T22:11:22,222222+00:00]'
-            FAKE_UTMP_7='[7] [999999] [tty2] [runner] [tty2] [          ] [0.0.0.0] [2022-02-22T22:22:22,222222+00:00]'
-            (echo "$FAKE_UTMP_2" ; echo "$FAKE_UTMP_7") | sudo utmpdump -r -o /var/run/utmp
-            # ... and add a full name to each account with a gecos field but no full name.
-            sudo sed -i 's/:,/:runner name,/' /etc/passwd
-            # We also create a couple optional files pinky looks for
-            touch /home/runner/.project
-            echo "foo" > /home/runner/.plan
-            # add user with digital username for testing with issue #7787
-            echo 200:x:2000:2000::/home/200:/bin/bash | sudo tee -a /etc/passwd
-            echo 200:x:2000: | sudo tee -a /etc/group
+            bash util/setup-gh-runner-utmp.sh
             ;;
         esac
     - uses: taiki-e/install-action@v2
@@ -1102,22 +1087,7 @@ jobs:
             # selinux and systemd headers needed to build tests
             sudo apt-get -y update
             sudo apt-get -y install libselinux1-dev libsystemd-dev
-            # pinky is a tool to show logged-in users from utmp, and gecos fields from /etc/passwd.
-            # In GitHub Action *nix VMs, no accounts log in, even the "runner" account that runs the commands, and "system boot" entry is missing.
-            # The account also has empty gecos fields.
-            # To work around these issues for pinky (and who) tests, we create a fake utmp file with a
-            # system boot entry and a login entry for the GH runner account.
-            FAKE_UTMP_2='[2] [00000] [~~  ] [reboot] [~   ] [6.0.0-test] [0.0.0.0] [2022-02-22T22:11:22,222222+00:00]'
-            FAKE_UTMP_7='[7] [999999] [tty2] [runner] [tty2] [          ] [0.0.0.0] [2022-02-22T22:22:22,222222+00:00]'
-            (echo "$FAKE_UTMP_2" ; echo "$FAKE_UTMP_7") | sudo utmpdump -r -o /var/run/utmp
-            # ... and add a full name to each account with a gecos field but no full name.
-            sudo sed -i 's/:,/:runner name,/' /etc/passwd
-            # We also create a couple optional files pinky looks for
-            touch /home/runner/.project
-            echo "foo" > /home/runner/.plan
-            # add user with digital username for testing with issue #7787
-            echo 200:x:2000:2000::/home/200:/bin/bash | sudo tee -a /etc/passwd
-            echo 200:x:2000: | sudo tee -a /etc/group
+            bash util/setup-gh-runner-utmp.sh
             ;;
         esac
 

src/uu/users/Cargo.toml

@@ -24,7 +24,7 @@ path = "src/users.rs"
 
 [dependencies]
 clap = { workspace = true }
-uucore = { workspace = true, features = ["utmpx"] }
+uucore = { workspace = true, features = ["utmpx", "process"] }
 fluent = { workspace = true }
 
 [target.'cfg(target_os = "openbsd")'.dependencies]

src/uu/users/src/users.rs

@@ -3,7 +3,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-// spell-checker:ignore (paths) wtmp
+// spell-checker:ignore (paths) wtmp ESRCH
 
 use std::ffi::OsString;
 use std::path::Path;
@@ -61,12 +61,15 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             }
         }
     };
+    // OpenBSD uses the older UTMP format (not UTMPX) which doesn't reliably track PIDs,
+    // so we only filter by pid_is_alive on non-OpenBSD systems.
     #[cfg(not(target_os = "openbsd"))]
     {
+        use uucore::process::pid_is_alive;
         let filename = maybe_file.unwrap_or(utmpx::DEFAULT_FILE.as_ref());
 
         users = Utmpx::iter_all_records_from(filename)
-            .filter(|ut| ut.is_user_process())
+            .filter(|ut| ut.is_user_process() && pid_is_alive(ut.pid()))
             .map(|ut| ut.user())
             .collect::<Vec<_>>();
     };

src/uu/who/Cargo.toml

@@ -25,7 +25,7 @@ path = "src/who.rs"
 
 [dependencies]
 clap = { workspace = true }
-uucore = { workspace = true, features = ["utmpx"] }
+uucore = { workspace = true, features = ["utmpx", "process"] }
 fluent = { workspace = true }
 
 [[bin]]

src/uu/who/locales/en-US.ftl

@@ -26,10 +26,7 @@ who-help-users = list users logged in
 who-help-mesg = add user's message status as +, - or ?
 
 # Output messages
-who-user-count = # { $count ->
-    [one] user={ $count }
-   *[other] users={ $count }
-}
+who-user-count = # users={ $count }
 
 # Idle time indicators
 who-idle-current =   .

src/uu/who/locales/fr-FR.ftl

@@ -25,10 +25,7 @@ who-help-users = liste les utilisateurs connectés
 who-help-mesg = ajoute le statut de message de l'utilisateur comme +, - ou ?
 
 # Output messages
-who-user-count = # { $count ->
-    [one] utilisateur={ $count }
-   *[other] utilisateurs={ $count }
-}
+who-user-count = # utilisateurs={ $count }
 
 # Idle time indicators
 who-idle-old = anc.

src/uu/who/src/platform/unix.rs

@@ -3,14 +3,15 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-// spell-checker:ignore (ToDO) ttyname hostnames runlevel mesg wtmp statted boottime deadprocs initspawn clockchange curr pidstr exitstr hoststr
+// spell-checker:ignore (ToDO) ttyname hostnames runlevel mesg wtmp statted boottime deadprocs initspawn clockchange curr pidstr exitstr hoststr ESRCH
 
 use crate::options;
 use crate::uu_app;
 
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult};
 use uucore::libc::{S_IWGRP, STDIN_FILENO, ttyname};
+use uucore::process::pid_is_alive;
 use uucore::translate;
 
 use uucore::utmpx::{self, UtmpxRecord, time};
@@ -210,7 +211,7 @@ impl Who {
         };
         if self.short_list {
             let users = utmpx::Utmpx::iter_all_records_from(f)
-                .filter(|ut| ut.is_user_process())
+                .filter(|ut| ut.is_user_process() && pid_is_alive(ut.pid()))
                 .map(|ut| ut.user())
                 .collect::<Vec<_>>();
             println!("{}", users.join(" "));
@@ -229,7 +230,7 @@ impl Who {
 
             for ut in records {
                 if !self.my_line_only || cur_tty == ut.tty_device() {
-                    if self.need_users && ut.is_user_process() {
+                    if self.need_users && ut.is_user_process() && pid_is_alive(ut.pid()) {
                         self.print_user(&ut)?;
                     } else {
                         match ut.record_type() {

src/uucore/src/lib/features/process.rs

@@ -8,8 +8,11 @@
 // spell-checker:ignore pgrep pwait snice getpgrp
 
 use libc::{gid_t, pid_t, uid_t};
-#[cfg(not(target_os = "redox"))]
 use nix::errno::Errno;
+#[cfg(not(target_os = "openbsd"))]
+use nix::sys::signal::kill;
+#[cfg(not(target_os = "openbsd"))]
+use nix::unistd::Pid;
 use std::io;
 use std::process::Child;
 use std::process::ExitStatus;
@@ -51,6 +54,30 @@ pub fn getpid() -> pid_t {
     unsafe { libc::getpid() }
 }
 
+/// Check if a process with the given PID is alive.
+///
+/// Uses `kill(pid, 0)` which sends signal 0 (null signal) to check process existence
+/// without actually sending a signal. This is a standard POSIX technique for checking
+/// if a process exists.
+///
+/// Returns `true` if:
+/// - The process exists (kill returns 0)
+/// - We lack permission to signal the process (errno != ESRCH)
+///   This means the process exists but we can't signal it
+///
+/// Returns `false` only if:
+/// - errno is ESRCH (No such process), confirming the process doesn't exist
+///
+/// PIDs <= 0 are considered alive for compatibility with utmp records that may
+/// contain special or invalid PID values.
+#[cfg(not(target_os = "openbsd"))]
+pub fn pid_is_alive(pid: i32) -> bool {
+    if pid <= 0 {
+        return true;
+    }
+    kill(Pid::from_raw(pid), None).is_ok() || Errno::last() != Errno::ESRCH
+}
+
 /// `getsid()` returns the session ID of the process with process ID pid.
 ///
 /// If pid is 0, getsid() returns the session ID of the calling process.

tests/by-util/test_users.rs

@@ -4,7 +4,7 @@
 // file that was distributed with this source code.
 use uutests::new_ucmd;
 #[cfg(any(target_vendor = "apple", target_os = "linux"))]
-use uutests::{util::TestScenario, util_name};
+use uutests::{unwrap_or_return, util::TestScenario, util::expected_result, util_name};
 
 #[test]
 fn test_invalid_arg() {
@@ -18,20 +18,10 @@ fn test_users_no_arg() {
 
 #[test]
 #[cfg(any(target_vendor = "apple", target_os = "linux"))]
-#[ignore = "issue #3219"]
 fn test_users_check_name() {
-    #[cfg(target_os = "linux")]
-    let util_name = util_name!();
-    #[cfg(target_vendor = "apple")]
-    let util_name = &format!("g{}", util_name!());
-
-    let expected = TestScenario::new(util_name)
-        .cmd(util_name)
-        .env("LC_ALL", "C")
-        .succeeds()
-        .stdout_move_str();
-
-    new_ucmd!().succeeds().stdout_is(&expected);
+    let ts = TestScenario::new(util_name!());
+    let expected_stdout = unwrap_or_return!(expected_result(&ts, &[])).stdout_move_str();
+    ts.ucmd().succeeds().stdout_is(expected_stdout);
 }
 
 #[test]

tests/by-util/test_who.rs

@@ -16,7 +16,6 @@ fn test_invalid_arg() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_count() {
     let ts = TestScenario::new(util_name!());
     for opt in ["-q", "--count", "--c"] {
@@ -42,7 +41,6 @@ fn test_boot() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_heading() {
     let ts = TestScenario::new(util_name!());
     for opt in ["-H", "--heading", "--head"] {
@@ -61,7 +59,6 @@ fn test_heading() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_short() {
     let ts = TestScenario::new(util_name!());
     for opt in ["-s", "--short", "--s"] {
@@ -128,7 +125,6 @@ fn test_time() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_mesg() {
     // -T, -w, --mesg
     //     add user's message status as +, - or ?
@@ -172,7 +168,6 @@ fn test_too_many_args() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_users() {
     let ts = TestScenario::new(util_name!());
     for opt in ["-u", "--users", "--us"] {
@@ -198,7 +193,6 @@ fn test_users() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_lookup() {
     let opt = "--lookup";
     let ts = TestScenario::new(util_name!());
@@ -219,7 +213,6 @@ fn test_dead() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_all_separately() {
     if cfg!(target_os = "macos") {
         // TODO: fix `-u`, see: test_users
@@ -237,7 +230,6 @@ fn test_all_separately() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
 fn test_all() {
     if cfg!(target_os = "macos") {
         // TODO: fix `-u`, see: test_users
@@ -253,7 +245,7 @@ fn test_all() {
 
 #[cfg(unix)]
 #[test]
-#[ignore = "issue #3219"]
+#[ignore = "This test is the only one in the suite that checks if the reference version is 8.3. This has not been the case for a while"]
 fn test_locale() {
     let ts = TestScenario::new(util_name!());
 

util/setup-gh-runner-utmp.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+# spell-checker:ignore utmpdump gecos
+# pinky is a tool to show logged-in users from utmp, and gecos fields from /etc/passwd.
+# In GitHub Action *nix VMs, no accounts log in, even the "runner" account that runs the commands, and "system boot" entry is missing.
+# The account also has empty gecos fields.
+# To work around these issues for pinky (and who) tests, we create a fake utmp file with a
+# system boot entry and a login entry for the GH runner account.
+printf '%s\n%s\n%s' \
+  '[2] [00000] [~~  ] [reboot  ] [~           ] [6.0.0-test                      ] [0.0.0.0        ] [2022-02-22T22:11:22,222222+0000]' \
+  '[7] [999999] [tty2] [runner  ] [tty2        ] [                    ] [0.0.0.0        ] [2022-02-22T22:22:22,222222+0000]' \
+  '[7] [00001] [tty3] [runner  ] [tty3        ] [                    ] [0.0.0.0        ] [2022-02-22T22:22:22,222222+0000]' \
+  | sudo utmpdump -r -o /var/run/utmp
+# ... and add a full name to each account with a gecos field but no full name.
+sudo sed -i 's/:,/:runner name,/' /etc/passwd
+# We also create a couple optional files pinky looks for
+touch /home/runner/.project
+echo "foo" > /home/runner/.plan
+# add user with digital username for testing with issue #7787
+echo 200:x:2000:2000::/home/200:/bin/bash | sudo tee -a /etc/passwd
+echo 200:x:2000: | sudo tee -a /etc/group