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ExecExt

subprocess

Trait ExecExt 

Source 
pub trait ExecExt {
    // Required methods
    fn setuid(self, uid: u32) -> Self;
    fn setgid(self, gid: u32) -> Self;
    fn setpgid(self) -> Self;
    unsafe fn pre_exec<F>(self, f: F) -> Self
       where F: FnMut() -> Result<()> + Send + Sync + 'static;
}
Available on Unix only.
Expand description

Extension trait for Unix-specific process creation options.

Required Methods§

Source

fn setuid(self, uid: u32) -> Self

Set the user ID for the spawned process.

The child process will run with the specified user ID, which affects file access permissions and process ownership. This calls setuid(2) in the child process after fork() but before exec().

Source

fn setgid(self, gid: u32) -> Self

Set the group ID for the spawned process.

The child process will run with the specified group ID, which affects file access permissions based on group ownership. This calls setgid(2) in the child process after fork() but before exec().

Source

fn setpgid(self) -> Self

Put the subprocess into its own process group.

This calls setpgid(0, 0) before exec’ing the child process, making it the leader of a new process group. Useful for a single process that spawns children, allowing them all to be signaled as a group with ProcessExt::send_signal_group.

For pipelines, use PipelineExt::setpgid instead, which puts all pipeline processes into a shared group.

Source

unsafe fn pre_exec<F>(self, f: F) -> Self
where F: FnMut() -> Result<()> + Send + Sync + 'static,

Schedule a closure to run in the child process between fork() and exec().

This is useful for performing setup that must happen in the child, such as setting resource limits, calling setsid(), or closing extra file descriptors.

Multiple closures can be registered and they will run in the order they were added. If any closure returns an error, the child process will exit and the error will be reported to the parent.

Closures run after all builder-configured setup and immediately before the exec(). To run code with the parent’s original privileges, omit the corresponding builder methods and drop privileges manually at the end of the closure.

§Safety

The closure runs after fork() in the child process. It must only call async-signal-safe functions. In particular, it must not allocate, acquire locks, or call into code that does so. Violating this may cause deadlocks or undefined behavior in the child process.

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§