[pbs-devel] [PATCH proxmox 1/2] sys: Use safe wrapper for libc::isatty

[Maximiliano Sandoval R]

Use the `std::io::IsTerminal` trait introduced in Rust 1.70.

Internally it calls `libc::isatty`, see [1, 2]. Note that it switches
the comparison from `== 1` to `!= 0` which shouldn't make a difference
assuming that libc::isatty upholds the promises made in its man page.

[1] https://doc.rust-lang.org/src/std/io/stdio.rs.html#1079
[2] https://doc.rust-lang.org/src/std/sys/unix/io.rs.html#79

Signed-off-by: Maximiliano Sandoval R <m.sandoval at proxmox.com>
---
 proxmox-sys/src/linux/tty.rs | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/proxmox-sys/src/linux/tty.rs b/proxmox-sys/src/linux/tty.rs
index fdea162..375e0ec 100644
--- a/proxmox-sys/src/linux/tty.rs
+++ b/proxmox-sys/src/linux/tty.rs
@@ -1,4 +1,4 @@
-use std::io::{self, Read, Write};
+use std::io::{self, IsTerminal, Read, Write};
 use std::mem::MaybeUninit;
 use std::os::unix::io::{AsRawFd, OwnedFd};
 
@@ -25,20 +25,14 @@ pub fn stdout_terminal_size() -> (usize, usize) {
     (winsize.ws_row as usize, winsize.ws_col as usize)
 }
 
-/// Returns whether the current stdout is a tty .
-/// # Safety
-///
-/// uses unsafe call to libc::isatty
+/// Returns whether the current stdout is a tty.
 pub fn stdout_isatty() -> bool {
-    unsafe { libc::isatty(std::io::stdin().as_raw_fd()) == 1 }
+    std::io::stdout().is_terminal()
 }
 
-/// Returns whether the current stdin is a tty .
-/// # Safety
-///
-/// uses unsafe call to libc::isatty
+/// Returns whether the current stdin is a tty.
 pub fn stdin_isatty() -> bool {
-    unsafe { libc::isatty(std::io::stdin().as_raw_fd()) == 1 }
+    std::io::stdin().is_terminal()
 }
 
 pub enum TtyOutput {
@@ -75,7 +69,7 @@ impl TtyOutput {
     /// Get an output file descriptor for the current terminal.
     pub fn open() -> io::Result<Option<Self>> {
         let stdout = std::io::stdout();
-        if unsafe { libc::isatty(stdout.as_raw_fd()) } == 1 {
+        if stdout.is_terminal() {
             Ok(Some(TtyOutput::Stdout(stdout)))
         } else {
             match crate::fd::open(
@@ -97,7 +91,7 @@ impl TtyOutput {
 /// first.
 pub fn read_password(query: &str) -> Result<Vec<u8>, Error> {
     let input = std::io::stdin();
-    if unsafe { libc::isatty(input.as_raw_fd()) } != 1 {
+    if !input.is_terminal() {
         let mut out = String::new();
         input.read_line(&mut out)?;
         return Ok(out.into_bytes());
-- 
2.39.2