System functions and processes

Documentation by function

Read fs and io to handle the file, TCP to link, and resolver to look up the address. Below are the process and lower level OS access rules.

Process Basics API

std::process::core
proc_exit(code: i32) -> !
proc_getpid() -> i64
proc_getppid() -> i64
proc_execve(path: str, argv: ptr<ptr<i8>>, envp: ptr<ptr<i8>>) -> i64
proc_waitpid_raw(pid: i64, status: ptr<i32>, options: i32) -> i64

proc_exit does not return to the call point. Please perform any necessary file/memory cleanup before shutdown. proc_execve differs from a typical child creation function because, if successful, it replaces the existing process image. raw argv/envp must be prepared for the NUL termination of each string, with the null pointer indicating the end.

The spawn function in std::process::spawn handles the creation result, and the await function handles the exit status of the child. Successful creation and successful termination of the program are two different things. When you create a pipe, the parent and child must close the unused end so that EOF is passed. If you wait for the child to exit without reading the capture pipe, the buffer may fill up and wait for each other.

Portability and low-level approach

fork/exec, file descriptor, and Windows handle are not the same OS function. Verify support for the selected target and treat unsupported as a normal failure path. std::sys is a OS-specific interface and does not reuse its numeric flags and layout from other OS.

When linking directly with the external C library, please read FFI. There is no need to arbitrarily declare the function libc to use the parent std API. Check Target and Link Environment first.