Remove unnecessary or broken code

src/common.rs

@@ -2981,37 +2981,6 @@ impl Groups {
     pub fn refresh_list(&mut self) {
         crate::sys::get_groups(&mut self.groups);
     }
-
-    /// Returns the [`Group`] matching the given `group_id`.
-    ///
-    /// **Important**: The group list must be filled before using this method, otherwise it will
-    /// always return `None` (through the `refresh_*` methods).
-    ///
-    /// It is a shorthand for:
-    ///
-    /// ```ignore
-    /// # use sysinfo::Groups;
-    /// let groups = Groups::new_with_refreshed_list();
-    /// groups.list().find(|user| user.id() == user_id);
-    /// ```
-    ///
-    /// Full example:
-    ///
-    /// ```no_run
-    /// use sysinfo::{Pid, System, Groups};
-    ///
-    /// let mut s = System::new_all();
-    /// let groups = Groups::new_with_refreshed_list();
-    ///
-    /// if let Some(process) = s.process(Pid::from(1337)) {
-    ///     if let Some(group_id) = process.group_id() {
-    ///         println!("User for process 1337: {:?}", groups.get_group_by_id(&group_id));
-    ///     }
-    /// }
-    /// ```
-    pub fn get_group_by_id(&self, group_id: &Gid) -> Option<&Group> {
-        self.groups.iter().find(|group| group.id() == group_id)
-    }
 }
 
 /// An enum representing signals on UNIX-like systems.

src/unix/apple/mod.rs

@@ -18,7 +18,6 @@ pub mod component;
 pub mod cpu;
 pub mod disk;
 mod ffi;
-pub mod groups;
 pub mod network;
 pub mod process;
 pub mod system;

src/unix/groups.rs

@@ -1,9 +1,8 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use crate::common::Gid;
-
-#[cfg(not(any(target_os = "macos", target_os = "ios")))]
-use crate::Group;
+use crate::{Gid, Group};
+use libc::{endgrent, getgrent, setgrent};
+use std::collections::HashMap;
 
 #[derive(PartialEq, Eq, PartialOrd, Ord, Debug)]
 pub(crate) struct GroupInner {
@@ -25,35 +24,37 @@ impl GroupInner {
     }
 }
 
-// Not used by mac.
-#[cfg(not(any(target_os = "macos", target_os = "ios")))]
 pub(crate) fn get_groups(groups: &mut Vec<Group>) {
-    use std::fs::File;
-    use std::io::Read;
+    groups.clear();
 
-    #[inline]
-    fn parse_id(id: &str) -> Option<u32> {
-        id.parse::<u32>().ok()
-    }
+    let mut groups_map = HashMap::with_capacity(10);
+
+    unsafe {
+        setgrent();
+        loop {
+            let gr = getgrent();
+            if gr.is_null() {
+                // The call was interrupted by a signal, retrying.
+                if std::io::Error::last_os_error().kind() == std::io::ErrorKind::Interrupted {
+                    continue;
+                }
+                break;
+            }
 
-    groups.clear();
+            if let Some(name) = crate::unix::utils::cstr_to_rust((*gr).gr_name) {
+                if groups_map.contains_key(&name) {
+                    continue;
+                }
 
-    let mut s = String::new();
-
-    let _ = File::open("/etc/group").and_then(|mut f| f.read_to_string(&mut s));
-    for line in s.lines() {
-        let mut parts = line.split(':');
-        if let Some(name) = parts.next() {
-            let mut parts = parts.skip(1);
-            // Skip the user if the uid cannot be parsed correctly
-            if let Some(gid) = parts.next().and_then(parse_id) {
-                groups.push(Group {
-                    inner: GroupInner::new(Gid(gid), name.to_owned()),
-                });
+                let gid = (*gr).gr_gid;
+                groups_map.insert(name, Gid(gid));
             }
         }
+        endgrent();
+    }
+    for (name, gid) in groups_map {
+        groups.push(Group {
+            inner: GroupInner::new(gid, name),
+        });
     }
 }
-
-#[cfg(any(target_os = "macos", target_os = "ios"))]
-pub(crate) use crate::unix::apple::groups::get_groups;