feat: add is_dumb public function

Author: ugur-eren

src/lib.rs

@@ -89,7 +89,7 @@ extern crate alloc;
 pub use crate::kb::Key;
 #[cfg(feature = "std")]
 pub use crate::term::{
-    user_attended, user_attended_stderr, Term, TermFamily, TermFeatures, TermTarget,
+    is_dumb, user_attended, user_attended_stderr, Term, TermFamily, TermFeatures, TermTarget,
 };
 #[cfg(feature = "std")]
 pub use crate::utils::{

src/term.rs

@@ -568,6 +568,17 @@ impl Term {
     }
 }
 
+/// A fast way to check if the application has a dumb terminal.
+///
+/// On Unix: `TERM` environment variable is not set or set to `dumb`.
+///
+/// On Windows: `TERM` environment variable is explicitly set to `dumb`.
+/// Native windows terminals typically do not set the `TERM` environment variable.
+#[inline]
+pub fn is_dumb() -> bool {
+    is_a_dumb_terminal()
+}
+
 /// A fast way to check if the application has a user attended for stdout.
 ///
 /// This means that stdout is connected to a terminal instead of a

src/unix_term.rs

@@ -21,6 +21,13 @@ pub(crate) fn is_a_terminal(out: &impl AsRawFd) -> bool {
     unsafe { libc::isatty(out.as_raw_fd()) != 0 }
 }
 
+pub(crate) fn is_a_dumb_terminal() -> bool {
+    match env::var("TERM") {
+        Ok(term) => term == "dumb",
+        Err(_) => true,
+    }
+}
+
 pub(crate) fn is_a_color_terminal(out: &Term) -> bool {
     if !is_a_terminal(out) {
         return false;
@@ -30,10 +37,7 @@ pub(crate) fn is_a_color_terminal(out: &Term) -> bool {
         return false;
     }
 
-    match env::var("TERM") {
-        Ok(term) => term != "dumb",
-        Err(_) => false,
-    }
+    !is_a_dumb_terminal()
 }
 
 pub(crate) fn is_a_true_color_terminal(out: &Term) -> bool {

src/wasm_term.rs

@@ -21,6 +21,11 @@ pub(crate) fn is_a_terminal(_out: &Term) -> bool {
     }
 }
 
+#[inline]
+pub(crate) fn is_a_dumb_terminal() -> bool {
+    false
+}
+
 #[inline]
 pub(crate) fn is_a_color_terminal(_out: &Term) -> bool {
     // We currently never report color terminals.  For discussion see

src/windows_term/mod.rs

@@ -59,6 +59,16 @@ pub(crate) fn is_a_terminal(out: &Term) -> bool {
     msys_tty_on(out)
 }
 
+pub(crate) fn is_a_dumb_terminal() -> bool {
+    // Native windows terminals typically do not set the TERM.
+    // We can only assume that if it is explicitly set to `dumb` then it is a dumb terminal.
+    // Otherwise, we assume it is not.
+    match env::var("TERM") {
+        Ok(term) => term == "dumb",
+        Err(_) => false,
+    }
+}
+
 pub(crate) fn is_a_color_terminal(out: &Term) -> bool {
     if !is_a_terminal(out) {
         return false;
@@ -67,10 +77,7 @@ pub(crate) fn is_a_color_terminal(out: &Term) -> bool {
         return false;
     }
     if msys_tty_on(out) {
-        return match env::var("TERM") {
-            Ok(term) => term != "dumb",
-            Err(_) => true,
-        };
+        return !is_a_dumb_terminal();
     }
     enable_ansi_on(out)
 }