just/src/platform.rs
Casey Rodarmor 2b294f0b30 Create platform module (#178)
Moves platform specific functionality into its own module.

Thanks to @Meralis40 for starting this!

This also gets just building on windows \^_^/

Although a lot of tests still fail (✖╭╮✖)

The `PlatformInterface` trait contains functions which abstract
over platform specific functionality, with implementations for
different platforms behind #[cfg(*)] attributes.

- `make_shebang_command()` constructs a command which will execute
  the given script as if by a shebang. On linux this executes the
  file, on windows it runs the interpreter directly.

- `set_execute_permission()` sets the execute permission on a
  file. This is a nop on windows, since all files are executable.

- `signal_from_exit_status()` extracts the signal a process was
  halted by from its exit status, if it was halted by a signal.
2017-04-21 22:20:13 -07:00

67 lines
2.1 KiB
Rust

use ::prelude::*;
pub struct Platform;
pub trait PlatformInterface {
/// Construct a command equivelant to running the script at `path` with the
/// shebang line `shebang`
fn make_shebang_command(path: &Path, command: &str, argument: Option<&str>) -> process::Command;
/// Set the execute permission on the file pointed to by `path`
fn set_execute_permission(path: &Path) -> Result<(), io::Error>;
/// Extract the signal from a process exit status, if it was terminated by a signal
fn signal_from_exit_status(exit_status: process::ExitStatus) -> Option<i32>;
}
#[cfg(unix)]
impl PlatformInterface for Platform {
fn make_shebang_command(path: &Path, _command: &str, _argument: Option<&str>) -> process::Command {
// shebang scripts can be executed directly on unix
process::Command::new(path)
}
fn set_execute_permission(path: &Path) -> Result<(), io::Error> {
use std::os::unix::fs::PermissionsExt;
// get current permissions
let mut permissions = fs::metadata(&path)?.permissions();
// set the execute bit
let current_mode = permissions.mode();
permissions.set_mode(current_mode | 0o100);
// set the new permissions
fs::set_permissions(&path, permissions)
}
fn signal_from_exit_status(exit_status: process::ExitStatus) -> Option<i32> {
use std::os::unix::process::ExitStatusExt;
exit_status.signal()
}
}
#[cfg(windows)]
impl PlatformInterface for Platform {
fn make_shebang_command(path: &Path, command: &str, argument: Option<&str>) -> process::Command {
let mut cmd = process::Command::new(command);
if let Some(argument) = argument {
cmd.arg(argument);
}
cmd.arg(path);
cmd
}
fn set_execute_permission(_path: &Path) -> Result<(), io::Error> {
// it is not necessary to set an execute permission on a script on windows,
// so this is a nop
Ok(())
}
fn signal_from_exit_status(_exit_status: process::ExitStatus) -> Option<i32> {
// The rust standard library does not expose a way to extract a signal
// from a process exit status, so just return None
None
}
}