sh: remove atty dependency

Author: grisenti

Cargo.lock

@@ -7,7 +7,6 @@ edition = "2021"
 plib = { path = "../plib" }
 gettext-rs.workspace = true
 libc.workspace = true
-atty = "0.2"
 
 [[bin]]
 name = "sh"

sh/Cargo.toml

@@ -15,7 +15,7 @@ use crate::shell::opened_files::{OpenedFile, OpenedFiles, STDIN_FILENO};
 use crate::shell::Shell;
 use crate::wordexp::expanded_word::ExpandedWord;
 use crate::wordexp::split_fields;
-use atty::Stream;
+use std::io::IsTerminal;
 use std::os::fd::{AsRawFd, RawFd};
 use std::time::Duration;
 
@@ -141,7 +141,7 @@ fn read_from_stdin(
     delimiter: u8,
     backslash_escape: bool,
 ) -> Result<ReadResult, BuiltinError> {
-    if atty::is(Stream::Stdin) {
+    if std::io::stdin().is_terminal() {
         let original_terminal_settings = shell.terminal.reset();
         shell.terminal.set_nonblocking();
 

sh/builtin/read.rs

@@ -8,9 +8,8 @@
 //
 
 use crate::os::errno::get_current_errno_value;
-use atty::Stream;
 use std::io;
-use std::io::Read;
+use std::io::{IsTerminal, Read};
 
 fn get_current_settings() -> libc::termios {
     // using zeroed here because terminos has additional members on some systems
@@ -98,5 +97,5 @@ pub fn read_nonblocking_char() -> Option<u8> {
 }
 
 pub fn is_attached_to_terminal() -> bool {
-    atty::is(Stream::Stdin) && atty::is(Stream::Stdout)
+    std::io::stdin().is_terminal() && std::io::stdout().is_terminal()
 }