feat(sort): add locale-aware numeric sorting support

Implement NumericLocaleSettings to handle thousands separators and decimal points based on locale. Update tokenization logic to accommodate blank thousands separators for numeric and human-numeric modes, improving parsing of locale-specific numbers. Also refactor numeric locale detection for safety/readability and clean up related initialization/spell-checker ignore.

Author: mattsu2020

src/uu/sort/src/sort.rs

@@ -63,11 +63,6 @@ use uucore::{format_usage, i18n};
 use crate::buffer_hint::automatic_buffer_size;
 use crate::tmp_dir::TmpDirWrapper;
 
-#[cfg(unix)]
-use nix::libc;
-#[cfg(unix)]
-use std::ffi::CStr;
-
 mod options {
     pub mod modes {
         pub const SORT: &str = "sort";
@@ -1326,44 +1321,15 @@ impl FieldSelector {
     }
 }
 
-#[cfg(unix)]
 fn detect_numeric_locale() -> NumericLocaleSettings {
     let mut settings = NumericLocaleSettings::default();
-    unsafe {
-        libc::setlocale(libc::LC_NUMERIC, c"".as_ptr());
-    }
-    let conv = unsafe { libc::localeconv() };
-    if conv.is_null() {
-        return settings;
-    }
-    let (decimal_ptr, thousands_ptr) = unsafe {
-        let conv = &*conv;
-        (conv.decimal_point, conv.thousands_sep)
+    settings.decimal_pt = Some(locale_decimal_pt());
+    settings.thousands_sep = match i18n::decimal::locale_grouping_separator().as_bytes() {
+        [b] => Some(*b),
+        _ => None,
     };
-
-    settings.decimal_pt = single_byte_from_locale_ptr(decimal_ptr);
-    settings.thousands_sep = single_byte_from_locale_ptr(thousands_ptr);
     settings
 }
-
-#[cfg(not(unix))]
-fn detect_numeric_locale() -> NumericLocaleSettings {
-    NumericLocaleSettings::default()
-}
-
-#[cfg(unix)]
-fn single_byte_from_locale_ptr(ptr: *const libc::c_char) -> Option<u8> {
-    if ptr.is_null() {
-        return None;
-    }
-    let bytes = unsafe { CStr::from_ptr(ptr).to_bytes() };
-    if bytes.len() == 1 {
-        Some(bytes[0])
-    } else {
-        None
-    }
-}
-
 /// Creates an `Arg` for a sort mode flag.
 fn make_sort_mode_arg(mode: &'static str, short: char, help: String) -> Arg {
     Arg::new(mode)