add fallback mime guess in case file(1) is not available

Cargo.lock

@@ -379,6 +379,7 @@ dependencies = [
  "futures",
  "indexmap 2.0.0",
  "libc",
+ "mime_guess",
  "natord",
  "notify",
  "parking_lot",
@@ -1051,6 +1052,22 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "mime"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
+
+[[package]]
+name = "mime_guess"
+version = "2.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4192263c238a5f0d0c6bfd21f336a313a4ce1c450542449ca191bb657b4642ef"
+dependencies = [
+ "mime",
+ "unicase",
+]
+
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -2004,6 +2021,15 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "497961ef93d974e23eb6f433eb5fe1b7930b659f06d12dec6fc44a8f554c0bba"
 
+[[package]]
+name = "unicase"
+version = "2.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7d2d4dafb69621809a81864c9c1b864479e1235c0dd4e199924b9742439ed89"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.13"

core/Cargo.toml

@@ -29,6 +29,7 @@ tracing       = "^0"
 trash         = "^3"
 unicode-width = "^0"
 yazi-prebuild = "^0"
+mime_guess = "2.0.4"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 clipboard-win = "^4"

core/src/external/file.rs

@@ -3,7 +3,7 @@ use std::collections::BTreeMap;
 use anyhow::{bail, Result};
 use futures::TryFutureExt;
 use shared::{MimeKind, Url};
-use tokio::process::Command;
+use tokio::{fs, io::AsyncReadExt, process::Command};
 use tracing::error;
 
 async fn _file(files: &[&Url]) -> Result<BTreeMap<Url, String>> {
@@ -36,5 +36,41 @@ async fn _file(files: &[&Url]) -> Result<BTreeMap<Url, String>> {
 }
 
 pub async fn file(files: &[impl AsRef<Url>]) -> Result<BTreeMap<Url, String>> {
-	_file(&files.iter().map(AsRef::as_ref).collect::<Vec<_>>()).await
+	let _files = &files.iter().map(AsRef::as_ref).collect::<Vec<_>>();
+	_file(_files).or_else(move |_| fallback(_files)).await
+}
+
+async fn fallback(files: &[&Url]) -> Result<BTreeMap<Url, String>> {
+	let mut mimes = BTreeMap::new();
+	for &file in files {
+		if let Ok(mime) = guess_mime(file).await {
+			mimes.insert(file.clone(), mime);
+		}
+	}
+
+	if mimes.is_empty() {
+		error!("failed to get mime types: {:?}", files);
+		bail!("failed to get mime types");
+	}
+
+	Ok(mimes)
+}
+
+async fn guess_mime(file: impl AsRef<Url>) -> Result<String> {
+	// First, try to guess mime type from file extenstion.
+	// If fail, either return "text/plain" or "application/octet-stream" by
+	// trying to convert 1kb of data to utf8 string
+	let file = file.as_ref();
+	match mime_guess::from_path(file).first() {
+		Some(mime) => Ok(mime.to_string()),
+		None => {
+			let mut buf = [0; 1024];
+			let num_bytes = fs::File::open(file).await?.read(&mut buf).await?;
+			if String::from_utf8(buf[..num_bytes].to_vec()).is_ok() {
+				Ok(String::from("text/plain"))
+			} else {
+				Ok(String::from("application/octet-stream"))
+			}
+		}
+	}
 }

shared/src/mime.rs

@@ -18,7 +18,7 @@ pub enum MimeKind {
 
 impl MimeKind {
 	pub fn new(s: &str) -> Self {
-		if s.starts_with("text/") || s.ends_with("/xml") || s.ends_with("/javascript") {
+		if s.starts_with("text/") || s.ends_with("/xml") || s.ends_with("/javascript") || s.ends_with("/x-sh") {
 			Self::Text
 		} else if s.starts_with("image/") {
 			Self::Image