You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: exec_loader.rs
    path of file: ./repos/occlum/src/libos/src/process/do_spawn
    
    the code of the file until where you have to start completion: use super::super::elf_file::*;
use super::ThreadRef;
use crate::fs::{AsINodeFile, FileMode, INodeExt};
use crate::prelude::*;
use rcore_fs::vfs::{FileType, INode, Metadata};
use std::ffi::CString;

/// Load an ELF file header or a script's interpreter header into a vector.
///
/// If the file is an executable binary, then just load this file's header.
/// If the file is an scri
    
fn parse_script_interpreter(file_buf: &Vec<u8>) -> Result<String> {
    let mut start = 2; // after '#', '!'
    const MAX_LEN: usize = 127;

    // skip whitespaced between shebang and interpreter
    while (start < file_buf.len())
        && (file_buf[start] == ' ' as u8 || file_buf[start] == '\t' as u8)
    {
        start += 1;
    }

    let end = file_buf
        .iter()
        .take(MAX_LEN)
        .position(|&c| c == '\n' as u8)
        .ok_or_else(|| errno!(EINVAL, "script parsing error"))?;

    let interpreter = std::str::from_utf8(&file_buf[start..end])
        .map_err(|e| errno!(ENOEXEC, "failed to get the script interpreter"))?;
    trace!("script file using interpreter: {:?}", interpreter);
    Ok(interpreter.to_owned())
}