76 lines
2.2 KiB
Rust
76 lines
2.2 KiB
Rust
// SPDX-License-Identifier: MPL-2.0
|
|
|
|
use crate::prelude::*;
|
|
|
|
/// Tries to parse a buffer as a shebang line.
|
|
///
|
|
/// If the buffer starts with `#!` and its header is a valid shebang sequence,
|
|
/// then the function returns `Ok(Some(parts))`, where `parts` is a `Vec` that
|
|
/// contains the path of and the arguments for the interpreter.
|
|
///
|
|
/// If the buffer starts with `#!` but some error occurs while parsing the
|
|
/// file, then `Err(_)` is returned. If the buffer does not start with `#!`,
|
|
/// then `Ok(None)` is returned.
|
|
pub fn parse_shebang_line(file_first_page: &[u8]) -> Result<Option<Vec<CString>>> {
|
|
if !file_first_page.starts_with(b"#!") {
|
|
// The file is not a shebang.
|
|
return Ok(None);
|
|
}
|
|
|
|
let Some(first_line_len) = file_first_page.iter().position(|&c| c == b'\n') else {
|
|
return_errno_with_message!(Errno::ENOEXEC, "the shebang line is too long");
|
|
};
|
|
|
|
// Skip `#!`.
|
|
let shebang_header = &file_first_page[2..first_line_len];
|
|
let mut shebang_argv = Vec::new();
|
|
for arg in shebang_header.split(|&c| c == b' ' || c == b'\t') {
|
|
if arg.is_empty() {
|
|
continue;
|
|
}
|
|
|
|
let arg = CString::new(arg).map_err(|_| {
|
|
Error::with_message(Errno::ENOEXEC, "unexpected nul terminator is found")
|
|
})?;
|
|
shebang_argv.push(arg);
|
|
}
|
|
|
|
if shebang_argv.is_empty() {
|
|
return_errno_with_message!(Errno::ENOEXEC, "no interpreter program is found");
|
|
}
|
|
|
|
Ok(Some(shebang_argv))
|
|
}
|
|
|
|
#[cfg(ktest)]
|
|
mod test {
|
|
use alloc::{ffi::CString, vec};
|
|
|
|
use ostd::prelude::*;
|
|
|
|
use super::parse_shebang_line;
|
|
|
|
#[ktest]
|
|
fn parse_shebang_line_with_multiple_args() {
|
|
const LINE1: &str = "#! /bin/bash -e\n";
|
|
let res = parse_shebang_line(LINE1.as_bytes()).unwrap().unwrap();
|
|
assert_eq!(
|
|
res,
|
|
vec![
|
|
CString::new("/bin/bash").unwrap(),
|
|
CString::new("-e").unwrap()
|
|
]
|
|
);
|
|
|
|
const LINE2: &str = "#! /bin/env python3 \n";
|
|
let res = parse_shebang_line(LINE2.as_bytes()).unwrap().unwrap();
|
|
assert_eq!(
|
|
res,
|
|
vec![
|
|
CString::new("/bin/env").unwrap(),
|
|
CString::new("python3").unwrap()
|
|
]
|
|
);
|
|
}
|
|
}
|