sh: remove unnecessary atty dep

CONTRIBUTING.md

@@ -14,7 +14,7 @@ There are several ways to contribute to posixutils-rs:
 3. Test coverage:  Integration tests, positive and negative, are complete, pass 100%
 4. Code coverage:  Automated code coverage data indicates 100%
 5. Translated:  All strings are internationalized, including common OS errors for common error cases.
-6. Audited:  An external party has reviewed and tested for correctness, 
+6. Audited:  An external party has reviewed and tested for correctness,
    POSIX compliance, security, races and similar issues.
 
 ### Coding considerations
@@ -29,12 +29,11 @@ There are several ways to contribute to posixutils-rs:
 ### CLI utility and Rust style guidelines
 
 1. `cargo fmt` is required.
-2. Ideal goal:  **Each utility should look like a standard Rust CLI program.** 
+2. Ideal goal:  **Each utility should look like a standard Rust CLI program.**
    Small, lightweight utility with command line processing,
    core algorithm, and zero external crate dependencies.
 3. "only std"  When an external crate is required, avoid mega-crates.  Prefer
-   std-only, or, tiny crates such as `atty` that perform a single,
-   lightweight function.
+   std-only, or, tiny crates that perform a single, lightweight function.
 4. Correctness, readability, performance, in that order.
    Code should be readable by unfamiliar developers.  Avoid dense,
    uncommented code.
@@ -58,4 +57,3 @@ There are several ways to contribute to posixutils-rs:
 * Provide any input data can that be used to reproduce the bug.
 * Provide any error output from the utility.
 * Describe expected results:  What did you expect to happen, and did not?
-

misc/Cargo.toml

@@ -9,7 +9,6 @@ rust-version.workspace = true
 
 [dependencies]
 clap.workspace = true
-libc.workspace = true
 gettext-rs.workspace = true
 
 [dev-dependencies]

misc/test.rs

@@ -11,8 +11,14 @@
 // - fix and test unary ops
 //
 
-use std::os::unix::fs::{FileTypeExt, MetadataExt, PermissionsExt};
-use std::path::Path;
+use std::{
+    io::IsTerminal,
+    os::{
+        fd::{BorrowedFd, RawFd},
+        unix::fs::{FileTypeExt, MetadataExt, PermissionsExt},
+    },
+    path::Path,
+};
 
 use gettextrs::{bind_textdomain_codeset, gettext, setlocale, textdomain, LocaleCategory};
 
@@ -132,17 +138,14 @@ fn eval_unary_path(op: &UnaryOp, s: &str) -> bool {
 }
 
 fn eval_terminal(s: &str) -> bool {
-    let fd = match s.parse::<u32>() {
+    let fd = match s.parse::<RawFd>() {
         Ok(f) => f,
         Err(_) => {
             return false;
         }
     };
 
-    // Normally, posixutils would use the atty crate.
-    // Passing an arbitrary fd requires unsafe isatty in this case.
-
-    unsafe { libc::isatty(fd as i32) == 1 }
+    unsafe { BorrowedFd::borrow_raw(fd).is_terminal() }
 }
 
 fn eval_unary(op_str: &str, s: &str) -> bool {

sh/Cargo.toml

@@ -7,7 +7,6 @@ edition = "2021"
 plib = { path = "../plib" }
 gettext-rs.workspace = true
 nix = { version = "0.29", features = ["process", "fs", "resource", "signal", "user", "term"] }
-atty = "0.2"
 
 [[bin]]
 name = "sh"

sh/src/builtin/read.rs

@@ -13,10 +13,12 @@ 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 nix::errno::Errno;
-use std::os::fd::{AsRawFd, RawFd};
-use std::time::Duration;
+use std::{io::stdin, time::Duration};
+use std::{
+    io::IsTerminal,
+    os::fd::{AsRawFd, RawFd},
+};
 
 fn bytes_to_string(bytes: Vec<u8>) -> Result<String, BuiltinError> {
     String::from_utf8(bytes.to_vec()).map_err(|_| "read: invalid UTF-8".into())
@@ -140,13 +142,13 @@ fn read_from_stdin(
     delimiter: u8,
     backslash_escape: bool,
 ) -> Result<ReadResult, BuiltinError> {
-    if atty::is(Stream::Stdin) {
+    if stdin().is_terminal() {
         let original_terminal_settings = shell.terminal.reset();
         shell.terminal.set_nonblocking();
 
         let result = read_until_from_non_blocking_fd(
             shell,
-            std::io::stdin().as_raw_fd(),
+            stdin().as_raw_fd(),
             delimiter,
             backslash_escape,
         );
@@ -155,7 +157,7 @@ fn read_from_stdin(
 
         result
     } else {
-        read_until_from_file(std::io::stdin().as_raw_fd(), delimiter, backslash_escape)
+        read_until_from_file(stdin().as_raw_fd(), delimiter, backslash_escape)
     }
 }
 

sh/src/cli/terminal.rs

@@ -7,11 +7,10 @@
 // SPDX-License-Identifier: MIT
 //
 
-use atty::Stream;
 use nix::sys::termios;
 use nix::sys::termios::{LocalFlags, Termios};
-use std::io;
 use std::io::Read;
+use std::io::{self, stdin, stdout, IsTerminal};
 use std::os::fd::AsFd;
 
 #[derive(Clone)]
@@ -81,5 +80,5 @@ pub fn read_nonblocking_char() -> Option<u8> {
 }
 
 pub fn is_attached_to_terminal() -> bool {
-    atty::is(Stream::Stdin) && atty::is(Stream::Stdout)
+    stdin().is_terminal() && stdout().is_terminal()
 }