async_std::os::unix::process

Trait CommandExt

Source 
pub trait CommandExt: Sealed {
    // Required methods
    fn uid(&mut self, id: u32) -> &mut Command;
    fn gid(&mut self, id: u32) -> &mut Command;
    fn exec(&mut self) -> Error;
    fn arg0<S>(&mut self, arg: S) -> &mut Command
       where S: AsRef<OsStr>;
}
Available on unstable only.
Expand description

Unix-specific extensions to the Command builder.

This trait is sealed: it cannot be implemented outside async-process. This is so that future additional methods are not breaking changes.

Required Methods§

Source

fn uid(&mut self, id: u32) -> &mut Command

Sets the child process’s user ID. This translates to a setuid call in the child process. Failure in the setuid call will cause the spawn to fail.

Source

fn gid(&mut self, id: u32) -> &mut Command

Similar to uid, but sets the group ID of the child process. This has the same semantics as the uid field.

Source

fn exec(&mut self) -> Error

Performs all the required setup by this Command, followed by calling the execvp syscall.

On success this function will not return, and otherwise it will return an error indicating why the exec (or another part of the setup of the Command) failed.

exec not returning has the same implications as calling std::process::exit – no destructors on the current stack or any other thread’s stack will be run. Therefore, it is recommended to only call exec at a point where it is fine to not run any destructors. Note, that the execvp syscall independently guarantees that all memory is freed and all file descriptors with the CLOEXEC option (set by default on all file descriptors opened by the standard library) are closed.

This function, unlike spawn, will not fork the process to create a new child. Like spawn, however, the default behavior for the stdio descriptors will be to inherited from the current process.

§Notes

The process may be in a “broken state” if this function returns in error. For example the working directory, environment variables, signal handling settings, various user/group information, or aspects of stdio file descriptors may have changed. If a “transactional spawn” is required to gracefully handle errors it is recommended to use the cross-platform spawn instead.

Source

fn arg0<S>(&mut self, arg: S) -> &mut Command
where S: AsRef<OsStr>,

Set executable argument

Set the first process argument, argv[0], to something other than the default executable path.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§