shell_env.rs

  1#![cfg_attr(not(unix), allow(unused))]
  2
  3use anyhow::{Context as _, Result};
  4use collections::HashMap;
  5
  6/// Capture all environment variables from the login shell.
  7#[cfg(unix)]
  8pub fn capture(directory: &std::path::Path) -> Result<collections::HashMap<String, String>> {
  9    use std::os::unix::process::CommandExt;
 10    use std::process::Stdio;
 11
 12    let zed_path = super::get_shell_safe_zed_path()?;
 13    let shell_path = std::env::var("SHELL").map(std::path::PathBuf::from)?;
 14    let shell_name = shell_path.file_name().and_then(std::ffi::OsStr::to_str);
 15
 16    let mut command_string = String::new();
 17    let mut command = std::process::Command::new(&shell_path);
 18    // In some shells, file descriptors greater than 2 cannot be used in interactive mode,
 19    // so file descriptor 0 (stdin) is used instead. This impacts zsh, old bash; perhaps others.
 20    // See: https://github.com/zed-industries/zed/pull/32136#issuecomment-2999645482
 21    const ENV_OUTPUT_FD: std::os::fd::RawFd = 0;
 22    let redir = match shell_name {
 23        Some("rc") => format!(">[1={}]", ENV_OUTPUT_FD), // `[1=0]`
 24        _ => format!(">&{}", ENV_OUTPUT_FD),             // `>&0`
 25    };
 26    command.stdin(Stdio::null());
 27    command.stdout(Stdio::piped());
 28    command.stderr(Stdio::piped());
 29
 30    match shell_name {
 31        Some("tcsh" | "csh") => {
 32            // For csh/tcsh, login shell requires passing `-` as 0th argument (instead of `-l`)
 33            command.arg0("-");
 34        }
 35        Some("fish") => {
 36            // in fish, asdf, direnv attach to the `fish_prompt` event
 37            command_string.push_str("emit fish_prompt;");
 38            command.arg("-l");
 39        }
 40        _ => {
 41            command.arg("-l");
 42        }
 43    }
 44    // cd into the directory, triggering directory specific side-effects (asdf, direnv, etc)
 45    command_string.push_str(&format!("cd '{}';", directory.display()));
 46    command_string.push_str(&format!("{} --printenv {}", zed_path, redir));
 47    command.args(["-i", "-c", &command_string]);
 48
 49    super::set_pre_exec_to_start_new_session(&mut command);
 50
 51    let (env_output, process_output) = spawn_and_read_fd(command, ENV_OUTPUT_FD)?;
 52    let env_output = String::from_utf8_lossy(&env_output);
 53
 54    anyhow::ensure!(
 55        process_output.status.success(),
 56        "login shell exited with {}. stdout: {:?}, stderr: {:?}",
 57        process_output.status,
 58        String::from_utf8_lossy(&process_output.stdout),
 59        String::from_utf8_lossy(&process_output.stderr),
 60    );
 61
 62    // Parse the JSON output from zed --printenv
 63    let env_map: collections::HashMap<String, String> = serde_json::from_str(&env_output)
 64        .with_context(|| "Failed to deserialize environment variables from json")?;
 65    Ok(env_map)
 66}
 67
 68#[cfg(unix)]
 69fn spawn_and_read_fd(
 70    mut command: std::process::Command,
 71    child_fd: std::os::fd::RawFd,
 72) -> anyhow::Result<(Vec<u8>, std::process::Output)> {
 73    use command_fds::{CommandFdExt, FdMapping};
 74    use std::io::Read;
 75
 76    let (mut reader, writer) = std::io::pipe()?;
 77
 78    command.fd_mappings(vec![FdMapping {
 79        parent_fd: writer.into(),
 80        child_fd,
 81    }])?;
 82
 83    let process = command.spawn()?;
 84    drop(command);
 85
 86    let mut buffer = Vec::new();
 87    reader.read_to_end(&mut buffer)?;
 88
 89    Ok((buffer, process.wait_with_output()?))
 90}
 91
 92pub fn print_env() {
 93    let env_vars: HashMap<String, String> = std::env::vars().collect();
 94    let json = serde_json::to_string_pretty(&env_vars).unwrap_or_else(|err| {
 95        eprintln!("Error serializing environment variables: {}", err);
 96        std::process::exit(1);
 97    });
 98    println!("{}", json);
 99    std::process::exit(0);
100}