Starting processes v0.1.0

posix_spawn and its file actions, and waiting for and signalling a child.

`SpawnFileActions`

pub struct SpawnFileActions {
    // private fields
}

Room for a posix_spawn_file_actions_t, which each C library sizes its own way and none larger than this. Only ever passed by address to the posix_spawn_file_actions_* calls, which initialize and read it.

Source

Constructors

`SpawnFileActions`

pub func SpawnFileActions() -> SpawnFileActions

Zeroed storage for posix_spawn_file_actions_init to initialize.

Returns: the storage

Source

`F_SETFD`

pub const F_SETFD: int32 = 2;

F_SETFD: the fcntl command that sets a descriptor's flags.

Source

`FD_CLOEXEC`

pub const FD_CLOEXEC: int32 = 1;

FD_CLOEXEC: close the descriptor when the process starts another program.

Source

`WNOHANG`

pub const WNOHANG: int32 = 1;

WNOHANG: have waitpid return at once when the child has not finished.

Source

`SIGKILL`

pub const SIGKILL: int32 = 9;

SIGKILL: the signal that ends a process at once and cannot be caught.

Source

`posix_spawnp`

pub extern func posix_spawnp(
    pid: *var int32,
    file: *char8,
    fileActions: *SpawnFileActions,
    attributes: *opaque,
    arguments: **char8,
    environment: **char8
) -> int32

Starts file, found through PATH when it has no slash, as a child process.

Source

Parameters

Name	Type	Description
`pid`	`*var int32`	receives the child's process identifier
`file`	`*char8`	the program, NUL-terminated
`fileActions`	`*SpawnFileActions`	the descriptor and directory setup to run in the child first, or null
`attributes`	`*opaque`	spawn attributes, or null for the defaults
`arguments`	`**char8`	the argument vector, its first entry the program's name, ended by null
`environment`	`**char8`	the environment, `NAME=VALUE` entries ended by null

Returns: zero, or an error number

`posix_spawn_file_actions_init`

pub extern func posix_spawn_file_actions_init(actions: *var SpawnFileActions) -> int32

Initializes an empty list of file actions.

Source

Parameters

Name	Type	Description
`actions`	`*var SpawnFileActions`	the storage to initialize

Returns: zero, or an error number

`posix_spawn_file_actions_destroy`

pub extern func posix_spawn_file_actions_destroy(actions: *var SpawnFileActions) -> int32

Releases what posix_spawn_file_actions_init and the actions added since set up.

Source

Parameters

Name	Type	Description
`actions`	`*var SpawnFileActions`	initialized file actions

Returns: zero, or an error number

`posix_spawn_file_actions_adddup2`

pub extern func posix_spawn_file_actions_adddup2(
    actions: *var SpawnFileActions,
    fd: int32,
    newFd: int32
) -> int32

Adds an action duplicating fd onto newFd in the child.

Source

Parameters

Name	Type	Description
`actions`	`*var SpawnFileActions`	initialized file actions
`fd`	`int32`	the descriptor to duplicate
`newFd`	`int32`	the descriptor it becomes

Returns: zero, or an error number

`posix_spawn_file_actions_addopen`

pub extern func posix_spawn_file_actions_addopen(
    actions: *var SpawnFileActions,
    fd: int32,
    path: *char8,
    flags: int32,
    mode: FileMode
) -> int32

Adds an action opening path as fd in the child.

Source

Parameters

Name	Type	Description
`actions`	`*var SpawnFileActions`	initialized file actions
`fd`	`int32`	the descriptor the file becomes
`path`	`*char8`	the file, NUL-terminated
`flags`	`int32`	the open flags
`mode`	`FileMode`	the permissions of a file the open creates

Returns: zero, or an error number

`posix_spawn_file_actions_addchdir_np`

pub extern func posix_spawn_file_actions_addchdir_np(
    actions: *var SpawnFileActions,
    path: *char8
) -> int32

Adds an action changing the child's working directory to path.

Source

Parameters

Name	Type	Description
`actions`	`*var SpawnFileActions`	initialized file actions
`path`	`*char8`	the directory, NUL-terminated

Returns: zero, or an error number

`waitpid`

pub extern func waitpid(
    pid: int32,
    status: *var int32,
    options: int32
) -> int32

Waits for a child to change state, and reports how it finished.

Source

Parameters

Name	Type	Description
`pid`	`int32`	the child's process identifier
`status`	`*var int32`	receives the encoded status
`options`	`int32`	zero to wait, or `WNOHANG` to return at once when the child is still running

Returns: the child's identifier, zero with WNOHANG when it is still running, or -1 with the reason in errno

`kill`

pub extern func kill(pid: int32, signal: int32) -> int32

Sends a signal to a process.

Source

Parameters

Name	Type	Description
`pid`	`int32`	the process
`signal`	`int32`	the signal number, such as `SIGKILL`

Returns: zero, or -1 with the reason in errno

`fcntl`

pub extern func fcntl(
    fd: int32,
    command: int32,
    ...
) -> int32

Performs a control operation on a descriptor, such as setting its flags with F_SETFD.

Source

Parameters

Name	Type	Description
`fd`	`int32`	the descriptor
`command`	`int32`	the operation
`...`

Returns: the operation's result, or -1 with the reason in errno

`__errno_location`

pub extern func __errno_location() -> *var int32

Returns the address of the calling thread's errno, where the C library calls above leave their reason.

Source

Returns: the errno's address

Name resolution

getaddrinfo and the list of addresses it returns.

System calls

The raw system-call entry points and the call numbers they take.

Edit this page on GitHub