alnyan/yggdrasil: implement binary resolution from PATH

library/std/src/sys/yggdrasil/process.rs

@@ -292,6 +292,8 @@ impl Command {
                 .chain(self.args.iter().map(|arg| arg.as_str())),
         );
 
+        let program = &super::util::resolve_binary(program).unwrap_or_else(|| program.to_owned());
+
         let envs = Vec::from_iter(self.env.iter().filter_map(|(key, value)| {
             if let Some(value) = value {
                 let key = key.to_str().unwrap();

library/std/src/sys/yggdrasil/util.rs

@@ -1,4 +1,6 @@
+use crate::env;
 use crate::mem::size_of;
+use crate::path::PathBuf;
 
 #[derive(Clone, Copy)]
 pub struct KStringList {
@@ -43,3 +45,24 @@ impl KStringList {
         base + (/* array len */1 + /* pair */ 2 * index) * size_of::<usize>()
     }
 }
+
+pub fn resolve_binary(name: &str) -> Option<String> {
+    // Already an absolute path
+    if name.starts_with('/') {
+        return None;
+    }
+
+    let Ok(path) = env::var("PATH") else {
+        return None;
+    };
+
+    for entry in path.split(':') {
+        let full_path = PathBuf::from(entry).join(name);
+
+        if full_path.exists() {
+            return Some(full_path.to_str().unwrap().to_owned());
+        }
+    }
+
+    None
+}