add util_cmd.rs, util_file.rs

src/util_cmd.rs

@@ -0,0 +1,26 @@
+
+use std::{
+    io::{self, Error, ErrorKind},
+    process::Command,
+};
+
+pub fn run_command_and_wait(cmd: &mut Command) -> io::Result<()> {
+    cmd.spawn()?.wait()?;
+    Ok(())
+}
+
+pub fn extract_package_and_wait(dir: &str, file_name: &str) -> io::Result<()> {
+    let mut cmd: Command;
+    if file_name.ends_with(".zip") {
+        cmd = Command::new("unzip");
+    } else if file_name.ends_with(".tar.gz") {
+        cmd = Command::new("tar");
+        cmd.arg("-xzvf");
+    } else {
+        let m: &str = &format!("Unknown file type: {}", file_name);
+        return Err(Error::new(ErrorKind::Other, m));
+    }
+    cmd.arg(file_name).current_dir(dir);
+    run_command_and_wait(&mut cmd)
+}
+