Can't run a system command in Windows - windows

Question

The Rust code is
use std::process::Command;
fn main() {
if cfg!(target_os = "windows") {
Command::new("cls").spawn().expect("cls command failed to start");
} else {
println!("Not windows");
}
}
and the error is
PS C:\dev\Rust\testing> cargo run
Compiling testing v0.1.0 (C:\dev\Rust\testing)
Finished dev [unoptimized + debuginfo] target(s) in 0.95s
Running `target\debug\testing.exe`
thread 'main' panicked at 'cls command failed to start: Os { code: 2, kind: NotFound, message: "The system cannot find the file
specified." }', src\main.rs:5:37
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
error: process didn't exit successfully: `target\debug\testing.exe` (exit code: 101)
with RUST_BACKTRACE="full":
PS C:\dev\Rust\testing> cargo run
Compiling testing v0.1.0 (C:\dev\Rust\testing)
Finished dev [unoptimized + debuginfo] target(s) in 1.12s
Running `target\debug\testing.exe`
thread 'main' panicked at 'cls command failed to start: Os { code: 2, kind: NotFound, message: "The system cannot find the file specified." }', src\main.rs:5:37
stack backtrace:
0: 0x7ff7c9ecf059 - std::backtrace_rs::backtrace::dbghelp::trace
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\..\..\backtrace\src\backtrace\dbghelp.rs:98
1: 0x7ff7c9ecf059 - std::backtrace_rs::backtrace::trace_unsynchronized
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\..\..\backtrace\src\backtrace\mod.rs:66
2: 0x7ff7c9ecf059 - std::sys_common::backtrace::_print_fmt
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\sys_common\backtrace.rs:79
3: 0x7ff7c9ecf059 - std::sys_common::backtrace::_print::{{impl}}::fmt
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\sys_common\backtrace.rs:58
4: 0x7ff7c9ee32fb - core::fmt::write
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\core\src\fmt\mod.rs:1080
5: 0x7ff7c9ecc598 - std::io::Write::write_fmt<std::sys::windows::stdio::Stderr>
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\io\mod.rs:1516
6: 0x7ff7c9ed1ae4 - std::sys_common::backtrace::_print
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\sys_common\backtrace.rs:61
7: 0x7ff7c9ed1ae4 - std::sys_common::backtrace::print
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\sys_common\backtrace.rs:48
8: 0x7ff7c9ed1ae4 - std::panicking::default_hook::{{closure}}
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panicking.rs:208
9: 0x7ff7c9ed16c8 - std::panicking::default_hook
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panicking.rs:227
10: 0x7ff7c9ed239f - std::panicking::rust_panic_with_hook
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panicking.rs:577
11: 0x7ff7c9ed1f05 - std::panicking::begin_panic_handler::{{closure}}
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panicking.rs:484
12: 0x7ff7c9ecf93f - std::sys_common::backtrace::__rust_end_short_backtrace<closure-0,!>
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\sys_common\backtrace.rs:153
13: 0x7ff7c9ed1eb9 - std::panicking::begin_panic_handler
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panicking.rs:483
14: 0x7ff7c9ee2590 - core::panicking::panic_fmt
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\core\src\panicking.rs:85
15: 0x7ff7c9ee23b3 - core::option::expect_none_failed
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\core\src\option.rs:1234
16: 0x7ff7c9ec11c8 - core::result::Result<std::process::Child, std::io::error::Error>::expect<std::process::Child,std::io::error::Error>
at C:\Users\sadic\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\result.rs:933
17: 0x7ff7c9ec5f8f - testing::main
at C:\dev\Rust\testing\src\main.rs:5
18: 0x7ff7c9ec31eb - core::ops::function::FnOnce::call_once<fn(),tuple<>>
at C:\Users\sadic\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\ops\function.rs:227
19: 0x7ff7c9ec1d7b - std::sys_common::backtrace::__rust_begin_short_backtrace<fn(),tuple<>>
at C:\Users\sadic\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\sys_common\backtrace.rs:137
20: 0x7ff7c9ec40e1 - std::rt::lang_start::{{closure}}<tuple<>>
at C:\Users\sadic\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\rt.rs:66
21: 0x7ff7c9ed25a3 - core::ops::function::impls::{{impl}}::call_once
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\library\core\src\ops\function.rs:280
22: 0x7ff7c9ed25a3 - std::panicking::try::do_call
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panicking.rs:381
23: 0x7ff7c9ed25a3 - std::panicking::try
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panicking.rs:345
24: 0x7ff7c9ed25a3 - std::panic::catch_unwind
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\panic.rs:382
25: 0x7ff7c9ed25a3 - std::rt::lang_start_internal
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4\/library\std\src\rt.rs:51
26: 0x7ff7c9ec40b3 - std::rt::lang_start<tuple<>>
at C:\Users\sadic\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\rt.rs:65
27: 0x7ff7c9ec6000 - main
28: 0x7ff7c9ee76c8 - invoke_main
at d:\agent\_work\63\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:78
29: 0x7ff7c9ee76c8 - __scrt_common_main_seh
at d:\agent\_work\63\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
30: 0x7ffef5167034 - BaseThreadInitThunk
31: 0x7ffef617d0d1 - RtlUserThreadStart
error: process didn't exit successfully: `target\debug\testing.exe` (exit code: 101)
in contrast I have a C++ source file doing exactly the same successfully
#include <stdlib.h>
int main() {
system("cls");
}
I installed rustup using rustup_init.exe from rustup.rs and I am using cargo nightly to run the program, the stable branch does the same thing, I also have installed mingw64 and llvm if that helps. I didn't found anyone with the same problem in the internet. So, what it's happening and what do I do to solve this?

Answer 1

The reason it doesn't work is because cls is not an executable on Windows, it's a command of the Windows command line interpreter.
So if you want to execute it, you instead have to execute cmd /c cls.
Command::new("cmd")
.args(&["/c", "cls"])
.spawn()
.expect("cls command failed to start")
.wait()
.expect("failed to wait");
Alternatively, if you just want to clear the screen, you could also use the console crate.
// console = "0.14.0"
let term = console::Term::stdout();
term.clear_screen().expect("failed clearing screen");
Related:
"Clear screen with Windows “cls” command in Java console application"
"Java: Clear the console"
While those questions are not related to Rust, they do elaborate on cls not being an executable.