From 047a6be73c35e83ab440a2f5291b16bba4c94639 Mon Sep 17 00:00:00 2001
From: aweinstock <avi@zellic.io>
Date: Fri, 27 Feb 2026 13:20:12 -0500
Subject: [PATCH] uucore: Permit 'D' as a decimal suffix modifier in size
 parsing for GNU compatibility.

truncate: Reject 'b' as a unit.
---
 src/uu/truncate/src/truncate.rs               | 30 ++++++++++++-------
 .../src/lib/features/parser/parse_size.rs     | 30 ++++++++++++-------
 tests/by-util/test_truncate.rs                |  4 +++
 3 files changed, 43 insertions(+), 21 deletions(-)

diff --git a/src/uu/truncate/src/truncate.rs b/src/uu/truncate/src/truncate.rs
index 4461a4db280..6f460cfd708 100644
--- a/src/uu/truncate/src/truncate.rs
+++ b/src/uu/truncate/src/truncate.rs
@@ -16,7 +16,7 @@ use uucore::error::{FromIo, UResult, USimpleError, UUsageError};
 use uucore::format_usage;
 use uucore::translate;
 
-use uucore::parser::parse_size::{ParseSizeError, parse_size_u64};
+use uucore::parser::parse_size::{ParseSizeError, Parser, allow_list_with_all_suffixes};
 
 #[derive(Debug, Eq, PartialEq)]
 enum TruncateMode {
@@ -298,7 +298,7 @@ fn is_modifier(c: char) -> bool {
 
 /// Parse a size string with optional modifier symbol as its first character.
 ///
-/// A size string is as described in [`parse_size_u64`]. The first character
+/// A size string is as described in [`Parser::parse_u64`]. The first character
 /// of `size_string` might be a modifier symbol, like `'+'` or
 /// `'<'`. The first element of the pair returned by this function
 /// indicates which modifier symbol was present, or
@@ -323,15 +323,20 @@ fn parse_mode_and_size(size_string: &str) -> Result<TruncateMode, ParseSizeError
         if is_modifier(c) {
             size_string = &size_string[1..];
         }
-        parse_size_u64(size_string).map(match c {
-            '+' => TruncateMode::Extend,
-            '-' => TruncateMode::Reduce,
-            '<' => TruncateMode::AtMost,
-            '>' => TruncateMode::AtLeast,
-            '/' => TruncateMode::RoundDown,
-            '%' => TruncateMode::RoundUp,
-            _ => TruncateMode::Absolute,
-        })
+        let allow_list = allow_list_with_all_suffixes("EgGkKmMPQRtTYZ");
+        let allow_list_ref = allow_list.iter().map(AsRef::as_ref).collect::<Vec<&str>>();
+        Parser::default()
+            .with_allow_list(&allow_list_ref)
+            .parse_u64(size_string)
+            .map(match c {
+                '+' => TruncateMode::Extend,
+                '-' => TruncateMode::Reduce,
+                '<' => TruncateMode::AtMost,
+                '>' => TruncateMode::AtLeast,
+                '/' => TruncateMode::RoundDown,
+                '%' => TruncateMode::RoundUp,
+                _ => TruncateMode::Absolute,
+            })
     } else {
         Err(ParseSizeError::ParseFailure(size_string.to_string()))
     }
@@ -351,6 +356,9 @@ mod tests {
         assert_eq!(parse_mode_and_size(">10"), Ok(TruncateMode::AtLeast(10)));
         assert_eq!(parse_mode_and_size("/10"), Ok(TruncateMode::RoundDown(10)));
         assert_eq!(parse_mode_and_size("%10"), Ok(TruncateMode::RoundUp(10)));
+        assert_eq!(parse_mode_and_size("1kB"), Ok(TruncateMode::Absolute(1000)));
+        assert_eq!(parse_mode_and_size("1kD"), Ok(TruncateMode::Absolute(1000)));
+        assert!(parse_mode_and_size("1b").is_err());
     }
 
     #[test]
diff --git a/src/uucore/src/lib/features/parser/parse_size.rs b/src/uucore/src/lib/features/parser/parse_size.rs
index 05c270e4cf8..cc7e5e9e2e4 100644
--- a/src/uucore/src/lib/features/parser/parse_size.rs
+++ b/src/uucore/src/lib/features/parser/parse_size.rs
@@ -244,16 +244,16 @@ impl<'parser> Parser<'parser> {
             "YiB" | "yiB" | "Y" | "y" => (1024, 8),
             "RiB" | "riB" | "R" | "r" => (1024, 9),
             "QiB" | "qiB" | "Q" | "q" => (1024, 10),
-            "KB" | "kB" => (1000, 1),
-            "MB" | "mB" => (1000, 2),
-            "GB" | "gB" => (1000, 3),
-            "TB" | "tB" => (1000, 4),
-            "PB" | "pB" => (1000, 5),
-            "EB" | "eB" => (1000, 6),
-            "ZB" | "zB" => (1000, 7),
-            "YB" | "yB" => (1000, 8),
-            "RB" | "rB" => (1000, 9),
-            "QB" | "qB" => (1000, 10),
+            "KB" | "kB" | "KD" | "kD" => (1000, 1),
+            "MB" | "mB" | "MD" | "mD" => (1000, 2),
+            "GB" | "gB" | "GD" | "gD" => (1000, 3),
+            "TB" | "tB" | "TD" | "tD" => (1000, 4),
+            "PB" | "pB" | "PD" | "pD" => (1000, 5),
+            "EB" | "eB" | "ED" | "eD" => (1000, 6),
+            "ZB" | "zB" | "ZD" | "zD" => (1000, 7),
+            "YB" | "yB" | "YD" | "yD" => (1000, 8),
+            "RB" | "rB" | "RD" | "rD" => (1000, 9),
+            "QB" | "qB" | "QD" | "qD" => (1000, 10),
             _ if numeric_string.is_empty() => return Err(ParseSizeError::parse_failure(size)),
             _ => return Err(ParseSizeError::invalid_suffix(size)),
         };
@@ -373,6 +373,16 @@ impl<'parser> Parser<'parser> {
     }
 }
 
+pub fn allow_list_with_all_suffixes(units: &str) -> Vec<String> {
+    let mut allow_list = Vec::with_capacity(4 * units.len());
+    for unit in units.chars() {
+        for suffix in &["", "iB", "B", "D"] {
+            allow_list.push(format!("{unit}{suffix}"));
+        }
+    }
+    allow_list
+}
+
 /// Parse a size string into a number of bytes
 /// using Default Parser (no custom settings)
 ///
diff --git a/tests/by-util/test_truncate.rs b/tests/by-util/test_truncate.rs
index 3057dcfbe68..a875d158bd1 100644
--- a/tests/by-util/test_truncate.rs
+++ b/tests/by-util/test_truncate.rs
@@ -254,6 +254,10 @@ fn test_invalid_numbers() {
         .args(&["-s", "0B", "file"])
         .fails()
         .stderr_contains("Invalid number: '0B'");
+    new_ucmd!()
+        .args(&["-s", "1b", "file"])
+        .fails()
+        .stderr_contains("Invalid number: '1b'");
 }
 
 #[test]