refactor: Replace stdin field with process field in DigestEngineProgram

src/digest_engine/program.rs

@@ -16,18 +16,19 @@ pub struct DigestEngineProgram {
     pub program: String,
     pub args: Vec<String>,
     pub supported: bool,
-    pub stdin: Option<tokio::io::BufWriter<std::process::ChildStdin>>,
+    process: Option<std::process::Child>,
 }
 
 impl DigestEngineProgram {
     pub fn new(program: &str, args: Vec<&str>) -> DigestEngineProgram {
         let program_path = get_program_path(program);
         let supported = program_path.is_ok();
+
         DigestEngineProgram {
             program: program_path.unwrap_or(program.to_string()),
             args: args.iter().map(|s| s.to_string()).collect(),
             supported,
-            stdin: None,
+            process: None,
         }
     }
 }