diff --git a/Cargo.lock b/Cargo.lock
index fdbcf78..d58ddd9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,217 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "bitflags"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "327762f6e5a765692301e5bb513e0d9fef63be86bbc14528052b1cd3e6f03e07"
+
+[[package]]
+name = "either"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a26ae43d7bcc3b814de94796a5e736d4029efb0ee900c12e2d54c993ad1a1e07"
+
+[[package]]
+name = "errno"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a258e46cdc063eb8519c00b9fc845fc47bcfca4130e2f08e88665ceda8474245"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "home"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5444c27eef6923071f7ebcc33e3444508466a76f7a2b93da00ed6e19f30c1ddb"
+dependencies = [
+ "windows-sys 0.48.0",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.151"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "302d7ab3130588088d277783b1e2d2e10c9e9e4a16dd9050e6ec93fb3e7048f4"
+
+[[package]]
+name = "linux-raw-sys"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4cd1a83af159aa67994778be9070f0ae1bd732942279cabb14f86f986a21456"
+
+[[package]]
+name = "once_cell"
+version = "1.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
+
+[[package]]
+name = "rustix"
+version = "0.38.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72e572a5e8ca657d7366229cdde4bd14c4eb5499a9573d4d366fe1b599daa316"
+dependencies = [
+ "bitflags",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "upt"
 version = "0.3.0"
+dependencies = [
+ "which",
+]
+
+[[package]]
+name = "which"
+version = "5.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9bf3ea8596f3a0dd5980b46430f2058dfe2c36a27ccfbb1845d6fbfcd9ba6e14"
+dependencies = [
+ "either",
+ "home",
+ "once_cell",
+ "rustix",
+ "windows-sys 0.48.0",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
+dependencies = [
+ "windows-targets 0.48.5",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.0",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
+dependencies = [
+ "windows_aarch64_gnullvm 0.48.5",
+ "windows_aarch64_msvc 0.48.5",
+ "windows_i686_gnu 0.48.5",
+ "windows_i686_msvc 0.48.5",
+ "windows_x86_64_gnu 0.48.5",
+ "windows_x86_64_gnullvm 0.48.5",
+ "windows_x86_64_msvc 0.48.5",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
+dependencies = [
+ "windows_aarch64_gnullvm 0.52.0",
+ "windows_aarch64_msvc 0.52.0",
+ "windows_i686_gnu 0.52.0",
+ "windows_i686_msvc 0.52.0",
+ "windows_x86_64_gnu 0.52.0",
+ "windows_x86_64_gnullvm 0.52.0",
+ "windows_x86_64_msvc 0.52.0",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
diff --git a/Cargo.toml b/Cargo.toml
index 9a4cc35..ea18f0b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,6 +10,9 @@ repository = "https://github.com/sigoden/upt"
 categories = ["command-line-utilities"]
 keywords = ["universal", "package", "management"]
 
+[dependencies]
+which = "5.0.0"
+
 [[bin]]
 doc = false
 name = "upt"
@@ -17,4 +20,4 @@ name = "upt"
 [profile.release]
 lto = true
 strip = true
-opt-level = "z"
\ No newline at end of file
+opt-level = "z"
diff --git a/src/subcommand.rs b/src/action.rs
similarity index 67%
rename from src/subcommand.rs
rename to src/action.rs
index bddff07..f36e908 100644
--- a/src/subcommand.rs
+++ b/src/action.rs
@@ -4,14 +4,14 @@ use std::cell::Cell;
 use std::str::FromStr;
 
 #[derive(Debug, Clone, PartialEq, Default)]
-pub(crate) struct SubCommand {
+pub(crate) struct Action {
     cmd: String,
     action: Option<String>,
     has_pkg: bool,
     options: Vec<Vec<String>>,
 }
 
-impl FromStr for SubCommand {
+impl FromStr for Action {
     type Err = UptError;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         if s.is_empty() {
@@ -21,7 +21,7 @@ impl FromStr for SubCommand {
         let mut has_pkg = false;
         let mut options: Vec<Vec<String>> = vec![];
         if words.len() < 2 {
-            return Err(UptError::InvalidSubcommand(s.to_string()));
+            return Err(UptError::InvalidAction(s.to_string()));
         }
         let (cmd, action, reminder) = if words[1].starts_with('-') || words[1] == "$" {
             (words[0].to_string(), None, &words[1..])
@@ -44,7 +44,7 @@ impl FromStr for SubCommand {
                 options.push(split(elem));
             }
         }
-        Ok(SubCommand {
+        Ok(Action {
             cmd,
             action,
             has_pkg,
@@ -53,10 +53,10 @@ impl FromStr for SubCommand {
     }
 }
 
-impl SubCommand {
+impl Action {
     /// Try to parse the command line arguemnts
     pub fn parse(&self, args: &[String], confirm: &str) -> Option<(Option<String>, bool)> {
-        if self.is_default() {
+        if self.invalid() {
             return None;
         }
         let (options, pkg) = self.parse_args(args)?;
@@ -77,7 +77,7 @@ impl SubCommand {
     }
 
     pub fn to_cmd(&self, pkg: &str, confirm: &str) -> Option<String> {
-        if self.is_default() {
+        if self.invalid() {
             return None;
         }
         let mut segs: Vec<&str> = vec![&self.cmd];
@@ -98,7 +98,7 @@ impl SubCommand {
 
     /// Genereate help message
     pub fn help(&self) -> Option<String> {
-        if self.is_default() {
+        if self.invalid() {
             return None;
         }
         let mut segs: Vec<String> = vec![self.cmd.clone()];
@@ -120,7 +120,7 @@ impl SubCommand {
         Some(segs.join(" "))
     }
 
-    fn is_default(&self) -> bool {
+    fn invalid(&self) -> bool {
         self == &Default::default()
     }
 
@@ -181,8 +181,8 @@ impl SubCommand {
 }
 
 /// used in vendor!
-pub(crate) fn must_from_str(s: &str, name: &str, field: &str) -> SubCommand {
-    match SubCommand::from_str(s) {
+pub(crate) fn must_from_str(s: &str, name: &str, field: &str) -> Action {
+    match Action::from_str(s) {
         Ok(p) => p,
         Err(_) => panic!("Failed to parse {}.{} from '{}' ", name, field, s),
     }
@@ -190,183 +190,183 @@ pub(crate) fn must_from_str(s: &str, name: &str, field: &str) -> SubCommand {
 
 #[cfg(test)]
 mod tests {
-    use super::SubCommand;
+    use super::Action;
     use std::str::FromStr;
 
-    macro_rules! check_subcommand_from_str {
+    macro_rules! check_action_from_str {
         ($input:expr, { $cmd:expr, $action:expr, [$([$($options:expr),* $(,)*]),*], $has_pkg:expr }) => {
-            let subcommand = SubCommand::from_str($input).unwrap();
-            let expect_subcommand = SubCommand {
+            let action = Action::from_str($input).unwrap();
+            let expect_action = Action {
                 cmd: $cmd.to_string(),
                 action: $action.map(|v| v.to_string()),
                 has_pkg: $has_pkg,
                 options: vec![$(vec![$($options.to_string(),)*],)*],
             };
-            assert_eq!(subcommand, expect_subcommand);
+            assert_eq!(action, expect_action);
         }
     }
 
     #[test]
-    fn test_subcommand_from_str() {
-        check_subcommand_from_str!(
+    fn test_action_from_str() {
+        check_action_from_str!(
             "upt install $",
             { "upt", Some("install"), [], true }
         );
-        check_subcommand_from_str!(
+        check_action_from_str!(
             "upt search $",
             { "upt", Some("search"), [], true }
         );
-        check_subcommand_from_str!(
+        check_action_from_str!(
             "apt list --installed",
             {"apt", Some("list"), [["--installed"]], false }
         );
-        check_subcommand_from_str!(
+        check_action_from_str!(
             "pacman -R -s $",
             { "pacman", None::<&str>, [["-R"], ["-s"]], true }
         );
-        check_subcommand_from_str!(
+        check_action_from_str!(
             "pacman -S -y -y",
             { "pacman", None::<&str>, [["-S"], ["-y"], ["-y"]], false }
         );
-        check_subcommand_from_str!(
+        check_action_from_str!(
             "pacman -S $",
             { "pacman", None::<&str>, [["-S"]], true }
         );
     }
 
-    macro_rules! check_subcommand_parse {
+    macro_rules! check_action_parse {
         ($input:expr, $confirm:expr, [$($args:expr),*], ($pkg:expr, $confirm_result:expr)) => {
             {
-                let subcommand = SubCommand::from_str($input).unwrap();
+                let action = Action::from_str($input).unwrap();
                 let args = vec![$($args.to_string()),*];
                 let pkg = if $pkg.len() == 0 {
                     None
                 } else {
                     Some($pkg.to_string())
                 };
-                assert_eq!(subcommand.parse(&args, $confirm).unwrap(), (pkg, $confirm_result));
+                assert_eq!(action.parse(&args, $confirm).unwrap(), (pkg, $confirm_result));
             }
         };
         ($input:expr, $confirm:expr, [$($args:expr),*]) => {
             {
-                let subcommand = SubCommand::from_str($input).unwrap();
+                let action = Action::from_str($input).unwrap();
                 let args = vec![ $($args.to_string()),*];
-                assert_eq!(subcommand.parse(&args, $confirm), None);
+                assert_eq!(action.parse(&args, $confirm), None);
             }
         }
     }
 
     #[test]
-    fn test_subcommand_parse() {
-        check_subcommand_parse!(
+    fn test_action_parse() {
+        check_action_parse!(
             "apt install $",
             "-y/--confirm",
             ["apt", "install", "vim"],
             ("vim", false)
         );
-        check_subcommand_parse!(
+        check_action_parse!(
             "apt install $",
             "-y/--confirm",
             ["apt", "install", "-y", "vim"],
             ("vim", true)
         );
-        check_subcommand_parse!(
+        check_action_parse!(
             "apt install $",
             "-y/--confirm",
             ["apt", "install", "--confirm", "vim"],
             ("vim", true)
         );
-        check_subcommand_parse!(
+        check_action_parse!(
             "apt install $",
             "-y/--confirm",
             ["apt", "install", "vim", "jq"],
             ("vim jq", false)
         );
-        check_subcommand_parse!("apt install $", "-y/--confirm", ["upt", "install", "vim"]);
-        check_subcommand_parse!("apt search $", "", ["apt", "search", "vim"], ("vim", false));
-        check_subcommand_parse!(
+        check_action_parse!("apt install $", "-y/--confirm", ["upt", "install", "vim"]);
+        check_action_parse!("apt search $", "", ["apt", "search", "vim"], ("vim", false));
+        check_action_parse!(
             "apt list --installed",
             "",
             ["apt", "list", "--installed"],
             ("", false)
         );
-        check_subcommand_parse!(
+        check_action_parse!(
             "pacman -R -s $",
             "--noconfirm",
             ["pacman", "-R", "-s", "--noconfirm", "vim"],
             ("vim", true)
         );
-        check_subcommand_parse!(
+        check_action_parse!(
             "pacman -R -s $",
             "--noconfirm",
             ["pacman", "-Rs", "vim"],
             ("vim", false)
         );
-        check_subcommand_parse!(
+        check_action_parse!(
             "pacman -R -s $",
             "--noconfirm",
             ["pacman", "-Rs", "--noconfirm", "vim", "jq"],
             ("vim jq", true)
         );
-        check_subcommand_parse!("pacman -S -y -y", "", ["pacman", "-Syy"], ("", false));
-        check_subcommand_parse!("pacman -S $", "", ["pacman", "-S", "vim"], ("vim", false));
-        check_subcommand_parse!("apt tsearch $", "", ["apt", "search"]);
-        check_subcommand_parse!("apt tupgrade", "", ["apt", "upgrade", "vim"]);
-        check_subcommand_parse!("pacman -S -y -y", "", ["pacman", "-Sy"]);
-        check_subcommand_parse!("pacman -S -y -y", "", ["pacman", "-Syyy"]);
-        check_subcommand_parse!("pacman -Q -i", "", ["pacman", "-Qiy"]);
+        check_action_parse!("pacman -S -y -y", "", ["pacman", "-Syy"], ("", false));
+        check_action_parse!("pacman -S $", "", ["pacman", "-S", "vim"], ("vim", false));
+        check_action_parse!("apt tsearch $", "", ["apt", "search"]);
+        check_action_parse!("apt tupgrade", "", ["apt", "upgrade", "vim"]);
+        check_action_parse!("pacman -S -y -y", "", ["pacman", "-Sy"]);
+        check_action_parse!("pacman -S -y -y", "", ["pacman", "-Syyy"]);
+        check_action_parse!("pacman -Q -i", "", ["pacman", "-Qiy"]);
     }
 
-    macro_rules! check_subcommand_to_cmd {
+    macro_rules! check_action_to_cmd {
         ($input:expr, ($pkg:expr, $confirm:expr), $cmd:expr) => {{
-            let subcommand = SubCommand::from_str($input).unwrap();
-            assert_eq!(subcommand.to_cmd($pkg, $confirm), Some($cmd.to_string()));
+            let action = Action::from_str($input).unwrap();
+            assert_eq!(action.to_cmd($pkg, $confirm), Some($cmd.to_string()));
         }};
         ($input:expr, ($pkg:expr, $confirm:expr)) => {{
-            let subcommand = SubCommand::from_str($input).unwrap();
-            assert!(subcommand.to_cmd($pkg, $confirm).is_none());
+            let action = Action::from_str($input).unwrap();
+            assert!(action.to_cmd($pkg, $confirm).is_none());
         }};
     }
 
     #[test]
-    fn test_subcommand_to_cmd() {
-        check_subcommand_to_cmd!("apt install $", ("vim", ""), "apt install vim");
-        check_subcommand_to_cmd!("apt install $", ("vim", "-y"), "apt install -y vim");
-        check_subcommand_to_cmd!("apt install $", ("vim jq", ""), "apt install vim jq");
-        check_subcommand_to_cmd!("apt search $", ("vim", ""), "apt search vim");
-        check_subcommand_to_cmd!("apt list --installed", ("", ""), "apt list --installed");
-        check_subcommand_to_cmd!(
+    fn test_action_to_cmd() {
+        check_action_to_cmd!("apt install $", ("vim", ""), "apt install vim");
+        check_action_to_cmd!("apt install $", ("vim", "-y"), "apt install -y vim");
+        check_action_to_cmd!("apt install $", ("vim jq", ""), "apt install vim jq");
+        check_action_to_cmd!("apt search $", ("vim", ""), "apt search vim");
+        check_action_to_cmd!("apt list --installed", ("", ""), "apt list --installed");
+        check_action_to_cmd!(
             "pacman -R -s $",
             ("vim", "--noconfirm"),
             "pacman -R -s --noconfirm vim"
         );
-        check_subcommand_to_cmd!("pacman -R -s $", ("vim", ""), "pacman -R -s vim");
-        check_subcommand_to_cmd!(
+        check_action_to_cmd!("pacman -R -s $", ("vim", ""), "pacman -R -s vim");
+        check_action_to_cmd!(
             "pacman -R -s $",
             ("vim jq", "--noconfirm"),
             "pacman -R -s --noconfirm vim jq"
         );
-        check_subcommand_to_cmd!("pacman -S -y -y", ("", ""), "pacman -S -y -y");
-        check_subcommand_to_cmd!("pacman -S $", ("vim", ""), "pacman -S vim");
+        check_action_to_cmd!("pacman -S -y -y", ("", ""), "pacman -S -y -y");
+        check_action_to_cmd!("pacman -S $", ("vim", ""), "pacman -S vim");
     }
 
-    macro_rules! check_subcommand_help {
+    macro_rules! check_action_help {
         ($input:expr, $help:expr) => {{
-            let subcommand = SubCommand::from_str($input).unwrap();
-            assert_eq!(subcommand.help(), Some($help.to_string()));
+            let action = Action::from_str($input).unwrap();
+            assert_eq!(action.help(), Some($help.to_string()));
         }};
         ($input:expr) => {{
-            let subcommand = SubCommand::from_str($input).unwrap();
-            assert!(subcommand.help().is_none());
+            let action = Action::from_str($input).unwrap();
+            assert!(action.help().is_none());
         }};
     }
 
     #[test]
-    fn test_subcommand_help() {
-        check_subcommand_help!("upt install $", "upt install <pkg>");
-        check_subcommand_help!("upt search $", "upt search <pkg>");
-        check_subcommand_help!("upt list -i/--installed", "upt list -i/--installed");
-        check_subcommand_help!("pacman -S -y -y", "pacman -S -y -y");
-        check_subcommand_help!("pacman -S $", "pacman -S <pkg>");
+    fn test_action_help() {
+        check_action_help!("upt install $", "upt install <pkg>");
+        check_action_help!("upt search $", "upt search <pkg>");
+        check_action_help!("upt list -i/--installed", "upt list -i/--installed");
+        check_action_help!("pacman -S -y -y", "pacman -S -y -y");
+        check_action_help!("pacman -S $", "pacman -S <pkg>");
     }
 }
diff --git a/src/error.rs b/src/error.rs
index 6516ede..d660f5c 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -4,10 +4,9 @@ use std::fmt;
 #[derive(Debug, PartialEq)]
 pub enum UptError {
     NoVendor(String),
-    NotSupportOS,
-    NotSupportTask,
+    NoTask,
     NotFoundTool,
-    InvalidSubcommand(String),
+    InvalidAction(String),
     InvalidArgs(String),
     DisplyHelp(String),
 }
@@ -18,14 +17,13 @@ impl fmt::Display for UptError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         use UptError::*;
         match self {
-            NoVendor(v) => write!(f, "Vendor {} is not supported.", v),
-            NotSupportOS => write!(f, "Your OS is not supported currently."),
-            NotSupportTask => write!(f, "The task is not supported by your OS."),
+            NoVendor(v) => write!(f, "The vendor {} is not supported.", v),
+            NoTask => write!(f, "The package management tool cannot perform the task."),
             NotFoundTool => write!(
                 f,
                 "No found package management tool, use `$UPT_TOOL` to specify one."
             ),
-            InvalidSubcommand(v) => write!(f, "Invalid subcommand '{}'.", v),
+            InvalidAction(v) => write!(f, "Invalid action '{}'.", v),
             InvalidArgs(v) => write!(f, "Invalid arguments.\n\n{}", v),
             DisplyHelp(v) => write!(f, "{}", v),
         }
diff --git a/src/lib.rs b/src/lib.rs
index ca2cdbd..020178a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,8 +1,8 @@
 #[macro_use]
 mod macros;
 
+mod action;
 mod error;
-mod subcommand;
 mod task;
 mod utils;
 mod vendor;
diff --git a/src/macros.rs b/src/macros.rs
index a26cf1e..856c5f3 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -16,7 +16,7 @@ macro_rules! vendors {
         )+
     ) => {
         pub fn init(name: &str) -> Result<$crate::Vendor, $crate::UptError> {
-            use $crate::subcommand::must_from_str;
+            use $crate::action::must_from_str;
             match name {
                 $(
                     $name => {
@@ -61,7 +61,7 @@ macro_rules! vendors {
 macro_rules! os_tools {
     ($($os:literal => $($tool:literal),+);+$(;)?) => {
         pub fn detect_tool() -> std::result::Result<$crate::Vendor, $crate::UptError> {
-            let os = crate::utils::detect_os().ok_or(UptError::NotSupportOS)?;
+            let os = crate::utils::detect_os().unwrap_or_default();
             let tools: Vec<&str> = match os.as_str() {
                 $(
                     $os => vec![$($tool),+].into_iter().filter_map(|v| which_cmd(v)).collect(),
diff --git a/src/utils.rs b/src/utils.rs
index 4a58c6f..3a5d8af 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1,19 +1,11 @@
-use std::process::{Command, Stdio};
-
-pub fn which(name: &str) -> bool {
-    Command::new(name)
-        .stdout(Stdio::null())
-        .stderr(Stdio::null())
-        .spawn()
-        .is_ok()
-}
+use which::which;
 
 pub fn find_tool(tools: &[&str]) -> Option<String> {
     match tools.len() {
         0 => None,
         1 => {
             let tool = &tools[0];
-            if which(tool) {
+            if which(tool).is_ok() {
                 Some(tool.to_string())
             } else {
                 None
@@ -24,7 +16,13 @@ pub fn find_tool(tools: &[&str]) -> Option<String> {
                 .iter()
                 .map(|tool| {
                     let tool = tool.to_string();
-                    std::thread::spawn(move || if which(&tool) { Some(tool) } else { None })
+                    std::thread::spawn(move || {
+                        if which(&tool).is_ok() {
+                            Some(tool)
+                        } else {
+                            None
+                        }
+                    })
                 })
                 .collect();
             for handle in handles {
diff --git a/src/vendor.rs b/src/vendor.rs
index dcace8a..99e4571 100644
--- a/src/vendor.rs
+++ b/src/vendor.rs
@@ -1,5 +1,5 @@
+use crate::action::Action;
 use crate::error::UptError;
-use crate::subcommand::SubCommand;
 use crate::task::Task;
 
 os_tools!(
@@ -368,14 +368,14 @@ vendors![
 pub struct Vendor {
     pub(crate) name: String,
     pub(crate) confirm: String,
-    pub(crate) install: SubCommand,
-    pub(crate) remove: SubCommand,
-    pub(crate) upgrade: SubCommand,
-    pub(crate) search: SubCommand,
-    pub(crate) info: SubCommand,
-    pub(crate) update_index: SubCommand,
-    pub(crate) upgrade_all: SubCommand,
-    pub(crate) list_installed: SubCommand,
+    pub(crate) install: Action,
+    pub(crate) remove: Action,
+    pub(crate) upgrade: Action,
+    pub(crate) search: Action,
+    pub(crate) info: Action,
+    pub(crate) update_index: Action,
+    pub(crate) upgrade_all: Action,
+    pub(crate) list_installed: Action,
 }
 
 impl Vendor {
@@ -423,7 +423,7 @@ impl Vendor {
             Task::UpgradeAll { confirm: yes } => self.upgrade_all.to_cmd("", self.yes_str(yes)),
             Task::ListInstalled => self.list_installed.to_cmd("", ""),
         };
-        cmd.ok_or(UptError::NotSupportTask)
+        cmd.ok_or(UptError::NoTask)
     }
 
     fn yes_str(&self, yes: &bool) -> &str {