cksum: implement --zero flag with newline/NUL replacement

src/uu/cksum/src/cksum.rs

@@ -19,7 +19,9 @@ use uucore::checksum::{
 use uucore::{
     encoding,
     error::{FromIo, UResult, USimpleError},
-    format_usage, help_about, help_section, help_usage, os_str_as_bytes, show,
+    format_usage, help_about, help_section, help_usage,
+    line_ending::LineEnding,
+    os_str_as_bytes, show,
     sum::{div_ceil, Digest},
 };
 
@@ -42,6 +44,7 @@ struct Options {
     length: Option<usize>,
     output_format: OutputFormat,
     asterisk: bool, // if we display an asterisk or not (--binary/--text)
+    line_ending: LineEnding,
 }
 
 /// Calculate checksum
@@ -173,7 +176,7 @@ where
             // Therefore, emit the bytes directly to stdout, without any attempt at encoding them.
             let _dropped_result = stdout().write_all(os_str_as_bytes(filename.as_os_str())?);
         }
-        println!("{after_filename}");
+        print!("{after_filename}{}", options.line_ending);
     }
 
     Ok(())
@@ -195,6 +198,7 @@ mod options {
     pub const WARN: &str = "warn";
     pub const IGNORE_MISSING: &str = "ignore-missing";
     pub const QUIET: &str = "quiet";
+    pub const ZERO: &str = "zero";
 }
 
 /// Determines whether to prompt an asterisk (*) in the output.
@@ -330,6 +334,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let (tag, asterisk) = handle_tag_text_binary_flags(&matches)?;
 
     let algo = detect_algo(algo_name, length)?;
+    let line_ending = LineEnding::from_zero_flag(matches.get_flag(options::ZERO));
 
     let output_format = if matches.get_flag(options::RAW) {
         OutputFormat::Raw
@@ -347,6 +352,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         tag,
         output_format,
         asterisk,
+        line_ending,
     };
 
     match matches.get_many::<OsString>(options::FILE) {
@@ -474,6 +480,15 @@ pub fn uu_app() -> Command {
                 .help("don't fail or report status for missing files")
                 .action(ArgAction::SetTrue),
         )
+        .arg(
+            Arg::new(options::ZERO)
+                .long(options::ZERO)
+                .short('z')
+                .help(
+                    "end each output line with NUL, not newline,\n and disable file name escaping",
+                )
+                .action(ArgAction::SetTrue),
+        )
         .after_help(AFTER_HELP)
 }