Add SystemExt::distribution_id()

src/apple/system.rs

@@ -605,6 +605,10 @@ impl SystemExt for System {
             }
         }
     }
+
+    fn distribution_id(&self) -> String {
+        std::env::consts::OS.to_owned()
+    }
 }
 
 impl Default for System {

src/freebsd/system.rs

@@ -361,6 +361,10 @@ impl SystemExt for System {
     fn os_version(&self) -> Option<String> {
         self.system_info.get_os_release()
     }
+
+    fn distribution_id(&self) -> String {
+        std::env::consts::OS.to_owned()
+    }
 }
 
 impl Default for System {

src/lib.rs

@@ -328,9 +328,10 @@ mod test {
 
     #[test]
     fn check_system_info() {
+        let s = System::new();
+
         // We don't want to test on unsupported systems.
         if System::IS_SUPPORTED {
-            let s = System::new();
             assert!(!s.name().expect("Failed to get system name").is_empty());
 
             assert!(!s
@@ -345,6 +346,8 @@ mod test {
                 .expect("Failed to get long OS version")
                 .is_empty());
         }
+
+        assert!(!s.distribution_id().is_empty());
     }
 
     #[test]

src/linux/system.rs

@@ -697,6 +697,25 @@ impl SystemExt for System {
     fn os_version(&self) -> Option<String> {
         get_system_info_android(InfoType::OsVersion)
     }
+
+    #[cfg(not(target_os = "android"))]
+    fn distribution_id(&self) -> String {
+        get_system_info_linux(
+            InfoType::DistributionID,
+            Path::new("/etc/os-release"),
+            Path::new(""),
+        )
+        .unwrap_or_else(|| std::env::consts::OS.to_owned())
+    }
+
+    #[cfg(target_os = "android")]
+    fn distribution_id(&self) -> String {
+        // Currently get_system_info_android doesn't support InfoType::DistributionID and always
+        // returns None. This call is done anyway for consistency with non-Android implementation
+        // and to suppress dead-code warning for DistributionID on Android.
+        get_system_info_android(InfoType::DistributionID)
+            .unwrap_or_else(|| std::env::consts::OS.to_owned())
+    }
 }
 
 impl Default for System {
@@ -722,6 +741,9 @@ enum InfoType {
     /// - Linux: The distributions name
     Name,
     OsVersion,
+    /// Machine-parseable ID of a distribution, see
+    /// https://www.freedesktop.org/software/systemd/man/os-release.html#ID=
+    DistributionID,
 }
 
 #[cfg(not(target_os = "android"))]
@@ -732,6 +754,7 @@ fn get_system_info_linux(info: InfoType, path: &Path, fallback_path: &Path) -> O
         let info_str = match info {
             InfoType::Name => "NAME=",
             InfoType::OsVersion => "VERSION_ID=",
+            InfoType::DistributionID => "ID=",
         };
 
         for line in reader.lines().flatten() {
@@ -750,6 +773,10 @@ fn get_system_info_linux(info: InfoType, path: &Path, fallback_path: &Path) -> O
     let info_str = match info {
         InfoType::OsVersion => "DISTRIB_RELEASE=",
         InfoType::Name => "DISTRIB_ID=",
+        InfoType::DistributionID => {
+            // lsb-release is inconsistent with os-release and unsupported.
+            return None;
+        }
     };
     for line in reader.lines().flatten() {
         if let Some(stripped) = line.strip_prefix(info_str) {
@@ -765,6 +792,10 @@ fn get_system_info_android(info: InfoType) -> Option<String> {
     let name: &'static [u8] = match info {
         InfoType::Name => b"ro.product.model\0",
         InfoType::OsVersion => b"ro.build.version.release\0",
+        InfoType::DistributionID => {
+            // Not supported.
+            return None;
+        }
     };
 
     let mut value_buffer = vec![0u8; libc::PROP_VALUE_MAX as usize];
@@ -798,6 +829,7 @@ mod test {
     fn lsb_release_fallback_android() {
         assert!(get_system_info_android(InfoType::OsVersion).is_some());
         assert!(get_system_info_android(InfoType::Name).is_some());
+        assert!(get_system_info_android(InfoType::DistributionID).is_none());
     }
 
     #[test]
@@ -844,6 +876,10 @@ DISTRIB_DESCRIPTION="Ubuntu 20.10"
             get_system_info_linux(InfoType::Name, &tmp1, Path::new("")),
             Some("Ubuntu".to_owned())
         );
+        assert_eq!(
+            get_system_info_linux(InfoType::DistributionID, &tmp1, Path::new("")),
+            Some("ubuntu".to_owned())
+        );
 
         // Check for the "fallback" path: "/etc/lsb-release"
         assert_eq!(
@@ -854,5 +890,9 @@ DISTRIB_DESCRIPTION="Ubuntu 20.10"
             get_system_info_linux(InfoType::Name, Path::new(""), &tmp2),
             Some("Ubuntu".to_owned())
         );
+        assert_eq!(
+            get_system_info_linux(InfoType::DistributionID, Path::new(""), &tmp2),
+            None
+        );
     }
 }

src/traits.rs

@@ -1235,6 +1235,23 @@ pub trait SystemExt: Sized + Debug + Default + Send + Sync {
     /// ```
     fn long_os_version(&self) -> Option<String>;
 
+    /// Returns the distribution id as defined by os-release,
+    /// or [`std::env::consts::OS`].
+    ///
+    /// See also
+    /// - https://www.freedesktop.org/software/systemd/man/os-release.html#ID=
+    /// - https://doc.rust-lang.org/std/env/consts/constant.OS.html
+    ///
+    /// **Important**: this information is computed every time this function is called.
+    ///
+    /// ```no_run
+    /// use sysinfo::{System, SystemExt};
+    ///
+    /// let s = System::new();
+    /// println!("Distribution ID: {:?}", s.distribution_id());
+    /// ```
+    fn distribution_id(&self) -> String;
+
     /// Returns the system hostname based off DNS
     ///
     /// **Important**: this information is computed every time this function is called.

src/unknown/system.rs

@@ -166,6 +166,10 @@ impl SystemExt for System {
         None
     }
 
+    fn distribution_id(&self) -> String {
+        std::env::consts::OS.to_owned()
+    }
+
     fn host_name(&self) -> Option<String> {
         None
     }

src/windows/system.rs

@@ -496,6 +496,10 @@ impl SystemExt for System {
         };
         Some(format!("{} ({})", major, build_number))
     }
+
+    fn distribution_id(&self) -> String {
+        std::env::consts::OS.to_owned()
+    }
 }
 
 impl Default for System {