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>;
}
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§
sourcefn uid(&mut self, id: u32) -> &mut Command
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.
sourcefn gid(&mut self, id: u32) -> &mut Command
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.
sourcefn exec(&mut self) -> Error
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.