Currently, the new API will only be available on macOS with
the intention of adding more POSIX systems to it incrementally
(such as Linux, etc.).
Changes:
* add `posix_spawn` wrappers in a separate container in
`os/posix_spawn.zig`
* rewrite `ChildProcess.spawnPosix` using `posix_spawn` targeting macOS
as `ChildProcess.spawnMacos`
* introduce a `posix_spawn` specific `std.c.waitpid` wrapper which
does return an error in case the child process failed to exec - this
is required for any process that was spawned using `posix_spawn`
mechanism as, by definition, the errors returned by `posix_spawn`
routine cover only the `fork`-equivalent; `pre-exec()` and `exec()`
steps are covered by a catch-all error `ECHILD` returned by `waitpid`
on unsuccessful execution, e.g., no such file error, etc.
The libc interface uses `stat` instead of `stat64` struct.
This fixes, among other things, `zig fmt` accidentally setting the
formatted file's permission to 000.
This adds a special CWD file descriptor, AT.FDCWD (-2), to refer to the
current working directory. The `*at(...)` functions look for this and
resolve relative paths against the stored CWD. Absolute paths are
dynamically matched against the stored Preopens.
"os.initPreopensWasi()" must be called before std.os functions will
resolve relative or absolute paths correctly. This is asserted at
runtime.
Support has been added for: `open`, `rename`, `mkdir`, `rmdir`, `chdir`,
`fchdir`, `link`, `symlink`, `unlink`, `readlink`, `fstatat`, `access`,
and `faccessat`.
This also includes limited support for `getcwd()` and `realpath()`.
These return an error if the CWD does not correspond to a Preopen with
an absolute path. They also do not currently expand symlinks.
Adds the `tcflag_t` type to the termios constants.
This is made to allow bitwise operations on the termios
constants without an integer cast, e.g.:
```zig
var raw = try std.os.tcgetattr(std.os.STDIN_FILENO);
raw.lflag &= std.os.linux.ECHO | std.os.linux.ICANON;
```
instead of
```zig
var raw = try std.os.tcgetattr(std.os.STDIN_FILENO);
raw.lflag &= ~@intCast(u32, std.os.linux.ECHO | std.os.linux.ICANON);
```
Contributes to #10181
* add team_info, area_info
* update signature for get_next_image_info
* add error checks for haiku system calls
* update and cleanup of haiku constants
Some systems (Solaris, OpenBSD, AIX) change their definitions of
sockaddr_storage to be larger than 128 bytes. This comment adds a new
constant in the `sockaddr` that defines the size for every system.
Fixes#9759
