Merge pull request #7192 from RenjiSann/cksum-fix-error-handling

cksum: Update error and flags handling to improver GNU's match

src/uu/cksum/src/cksum.rs

@@ -13,8 +13,9 @@ use std::iter;
 use std::path::Path;
 use uucore::checksum::{
     calculate_blake2b_length, detect_algo, digest_reader, perform_checksum_validation,
-    ChecksumError, ChecksumOptions, ALGORITHM_OPTIONS_BLAKE2B, ALGORITHM_OPTIONS_BSD,
+    ChecksumError, ChecksumOptions, ChecksumVerbose, ALGORITHM_OPTIONS_BLAKE2B,
-    ALGORITHM_OPTIONS_CRC, ALGORITHM_OPTIONS_CRC32B, ALGORITHM_OPTIONS_SYSV, SUPPORTED_ALGORITHMS,
+    ALGORITHM_OPTIONS_BSD, ALGORITHM_OPTIONS_CRC, ALGORITHM_OPTIONS_CRC32B, ALGORITHM_OPTIONS_SYSV,
+    SUPPORTED_ALGORITHMS,
 };
 use uucore::{
     encoding,
@@ -322,13 +323,14 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             || iter::once(OsStr::new("-")).collect::<Vec<_>>(),
             |files| files.map(OsStr::new).collect::<Vec<_>>(),
         );
+
+        let verbose = ChecksumVerbose::new(status, quiet, warn);
+
         let opts = ChecksumOptions {
             binary: binary_flag,
             ignore_missing,
-            quiet,
-            status,
             strict,
-            warn,
+            verbose,
         };
 
         return perform_checksum_validation(files.iter().copied(), algo_option, length, opts);
@@ -462,19 +464,22 @@ pub fn uu_app() -> Command {
                 .short('w')
                 .long("warn")
                 .help("warn about improperly formatted checksum lines")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with_all([options::STATUS, options::QUIET]),
         )
         .arg(
             Arg::new(options::STATUS)
                 .long("status")
                 .help("don't output anything, status code shows success")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with_all([options::WARN, options::QUIET]),
         )
         .arg(
             Arg::new(options::QUIET)
                 .long(options::QUIET)
                 .help("don't print OK for each successfully verified file")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with_all([options::WARN, options::STATUS]),
         )
         .arg(
             Arg::new(options::IGNORE_MISSING)

src/uu/hashsum/src/hashsum.rs

@@ -24,6 +24,7 @@ use uucore::checksum::escape_filename;
 use uucore::checksum::perform_checksum_validation;
 use uucore::checksum::ChecksumError;
 use uucore::checksum::ChecksumOptions;
+use uucore::checksum::ChecksumVerbose;
 use uucore::checksum::HashAlgorithm;
 use uucore::error::{FromIo, UResult};
 use uucore::sum::{Digest, Sha3_224, Sha3_256, Sha3_384, Sha3_512, Shake128, Shake256};
@@ -240,13 +241,14 @@ pub fn uumain(mut args: impl uucore::Args) -> UResult<()> {
             || iter::once(OsStr::new("-")).collect::<Vec<_>>(),
             |files| files.map(OsStr::new).collect::<Vec<_>>(),
         );
+
+        let verbose = ChecksumVerbose::new(status, quiet, warn);
+
         let opts = ChecksumOptions {
             binary,
             ignore_missing,
-            quiet,
-            status,
             strict,
-            warn,
+            verbose,
         };
 
         // Execute the checksum validation
@@ -356,14 +358,16 @@ pub fn uu_app_common() -> Command {
                 .short('q')
                 .long(options::QUIET)
                 .help("don't print OK for each successfully verified file")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with_all([options::STATUS, options::WARN]),
         )
         .arg(
             Arg::new(options::STATUS)
                 .short('s')
                 .long("status")
                 .help("don't output anything, status code shows success")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with_all([options::QUIET, options::WARN]),
         )
         .arg(
             Arg::new(options::STRICT)
@@ -382,7 +386,8 @@ pub fn uu_app_common() -> Command {
                 .short('w')
                 .long("warn")
                 .help("warn about improperly formatted checksum lines")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with_all([options::QUIET, options::STATUS]),
         )
         .arg(
             Arg::new("zero")

src/uucore/src/lib/features/checksum.rs

@@ -19,7 +19,7 @@ use std::{
 };
 
 use crate::{
-    error::{set_exit_code, FromIo, UError, UResult, USimpleError},
+    error::{FromIo, UError, UResult, USimpleError},
     os_str_as_bytes, os_str_from_bytes, read_os_string_lines, show, show_error, show_warning_caps,
     sum::{
         Blake2b, Blake3, Digest, DigestWriter, Md5, Sha1, Sha224, Sha256, Sha384, Sha3_224,
@@ -130,10 +130,12 @@ impl From<ChecksumError> for LineCheckError {
 enum FileCheckError {
     /// a generic UError was encountered in sub-functions
     UError(Box<dyn UError>),
-    /// the checksum file is improperly formatted.
-    ImproperlyFormatted,
     /// reading of the checksum file failed
     CantOpenChecksumFile,
+    /// processing of the file is considered as a failure regarding the
+    /// provided flags. This however does not stop the processing of
+    /// further files.
+    Failed,
 }
 
 impl From<Box<dyn UError>> for FileCheckError {
@@ -148,15 +150,57 @@ impl From<ChecksumError> for FileCheckError {
     }
 }
 
+#[derive(Debug, PartialEq, Eq, PartialOrd, Clone, Copy)]
+pub enum ChecksumVerbose {
+    Status,
+    Quiet,
+    Normal,
+    Warning,
+}
+
+impl ChecksumVerbose {
+    pub fn new(status: bool, quiet: bool, warn: bool) -> Self {
+        use ChecksumVerbose::*;
+
+        // Assume only one of the three booleans will be enabled at once.
+        // This is ensured by clap's overriding arguments.
+        match (status, quiet, warn) {
+            (true, _, _) => Status,
+            (_, true, _) => Quiet,
+            (_, _, true) => Warning,
+            _ => Normal,
+        }
+    }
+
+    #[inline]
+    pub fn over_status(self) -> bool {
+        self > Self::Status
+    }
+
+    #[inline]
+    pub fn over_quiet(self) -> bool {
+        self > Self::Quiet
+    }
+
+    #[inline]
+    pub fn at_least_warning(self) -> bool {
+        self >= Self::Warning
+    }
+}
+
+impl Default for ChecksumVerbose {
+    fn default() -> Self {
+        Self::Normal
+    }
+}
+
 /// This struct regroups CLI flags.
 #[derive(Debug, Default, Clone, Copy)]
 pub struct ChecksumOptions {
     pub binary: bool,
     pub ignore_missing: bool,
-    pub quiet: bool,
-    pub status: bool,
     pub strict: bool,
-    pub warn: bool,
+    pub verbose: ChecksumVerbose,
 }
 
 #[derive(Debug, Error)]
@@ -235,20 +279,19 @@ pub fn create_sha3(bits: Option<usize>) -> UResult<HashAlgorithm> {
 }
 
 #[allow(clippy::comparison_chain)]
-fn cksum_output(res: &ChecksumResult, status: bool) {
+fn print_cksum_report(res: &ChecksumResult) {
     if res.bad_format == 1 {
         show_warning_caps!("{} line is improperly formatted", res.bad_format);
     } else if res.bad_format > 1 {
         show_warning_caps!("{} lines are improperly formatted", res.bad_format);
     }
 
-    if !status {
+    if res.failed_cksum == 1 {
-        if res.failed_cksum == 1 {
+        show_warning_caps!("{} computed checksum did NOT match", res.failed_cksum);
-            show_warning_caps!("{} computed checksum did NOT match", res.failed_cksum);
+    } else if res.failed_cksum > 1 {
-        } else if res.failed_cksum > 1 {
+        show_warning_caps!("{} computed checksums did NOT match", res.failed_cksum);
-            show_warning_caps!("{} computed checksums did NOT match", res.failed_cksum);
-        }
     }
+
     if res.failed_open_file == 1 {
         show_warning_caps!("{} listed file could not be read", res.failed_open_file);
     } else if res.failed_open_file > 1 {
@@ -284,10 +327,10 @@ impl FileChecksumResult {
 
     /// The cli options might prevent to display on the outcome of the
     /// comparison on STDOUT.
-    fn can_display(&self, opts: ChecksumOptions) -> bool {
+    fn can_display(&self, verbose: ChecksumVerbose) -> bool {
         match self {
-            FileChecksumResult::Ok => !opts.status && !opts.quiet,
+            FileChecksumResult::Ok => verbose.over_quiet(),
-            FileChecksumResult::Failed => !opts.status,
+            FileChecksumResult::Failed => verbose.over_status(),
             FileChecksumResult::CantOpen => true,
         }
     }
@@ -310,9 +353,9 @@ fn print_file_report<W: Write>(
     filename: &[u8],
     result: FileChecksumResult,
     prefix: &str,
-    opts: ChecksumOptions,
+    verbose: ChecksumVerbose,
 ) {
-    if result.can_display(opts) {
+    if result.can_display(verbose) {
         let _ = write!(w, "{prefix}");
         let _ = w.write_all(filename);
         let _ = writeln!(w, ": {result}");
@@ -589,7 +632,7 @@ fn get_file_to_check(
                 filename_bytes,
                 FileChecksumResult::CantOpen,
                 "",
-                opts,
+                opts.verbose,
             );
         };
         match File::open(filename) {
@@ -648,12 +691,11 @@ fn get_input_file(filename: &OsStr) -> UResult<Box<dyn Read>> {
 fn identify_algo_name_and_length(
     line_info: &LineInfo,
     algo_name_input: Option<&str>,
+    last_algo: &mut Option<String>,
 ) -> Option<(String, Option<usize>)> {
-    let algorithm = line_info
+    let algo_from_line = line_info.algo_name.clone().unwrap_or_default();
-        .algo_name
+    let algorithm = algo_from_line.to_lowercase();
-        .clone()
+    *last_algo = Some(algo_from_line);
-        .unwrap_or_default()
-        .to_lowercase();
 
     // check if we are called with XXXsum (example: md5sum) but we detected a different algo parsing the file
     // (for example SHA1 (f) = d...)
@@ -711,7 +753,7 @@ fn compute_and_check_digest_from_file(
         filename,
         FileChecksumResult::from_bool(checksum_correct),
         prefix,
-        opts,
+        opts.verbose,
     );
 
     if checksum_correct {
@@ -726,11 +768,13 @@ fn process_algo_based_line(
     line_info: &LineInfo,
     cli_algo_name: Option<&str>,
     opts: ChecksumOptions,
+    last_algo: &mut Option<String>,
 ) -> Result<(), LineCheckError> {
     let filename_to_check = line_info.filename.as_slice();
 
-    let (algo_name, algo_byte_len) = identify_algo_name_and_length(line_info, cli_algo_name)
+    let (algo_name, algo_byte_len) =
-        .ok_or(LineCheckError::ImproperlyFormatted)?;
+        identify_algo_name_and_length(line_info, cli_algo_name, last_algo)
+            .ok_or(LineCheckError::ImproperlyFormatted)?;
 
     // If the digest bitlen is known, we can check the format of the expected
     // checksum with it.
@@ -789,13 +833,13 @@ fn process_non_algo_based_line(
 /// matched the expected.
 /// If the comparison didn't happen, return a `LineChecksumError`.
 fn process_checksum_line(
-    filename_input: &OsStr,
     line: &OsStr,
     i: usize,
     cli_algo_name: Option<&str>,
     cli_algo_length: Option<usize>,
     opts: ChecksumOptions,
     cached_regex: &mut Option<LineFormat>,
+    last_algo: &mut Option<String>,
 ) -> Result<(), LineCheckError> {
     let line_bytes = os_str_as_bytes(line)?;
 
@@ -806,34 +850,19 @@ fn process_checksum_line(
 
     // Use `LineInfo` to extract the data of a line.
     // Then, depending on its format, apply a different pre-treatment.
-    if let Some(line_info) = LineInfo::parse(line, cached_regex) {
+    let Some(line_info) = LineInfo::parse(line, cached_regex) else {
-        if line_info.format == LineFormat::AlgoBased {
+        return Err(LineCheckError::ImproperlyFormatted);
-            process_algo_based_line(&line_info, cli_algo_name, opts)
+    };
-        } else if let Some(cli_algo) = cli_algo_name {
-            // If we match a non-algo based regex, we expect a cli argument
-            // to give us the algorithm to use
-            process_non_algo_based_line(i, &line_info, cli_algo, cli_algo_length, opts)
-        } else {
-            // We have no clue of what algorithm to use
-            return Err(LineCheckError::ImproperlyFormatted);
-        }
-    } else {
-        if opts.warn {
-            let algo = if let Some(algo_name_input) = cli_algo_name {
-                algo_name_input.to_uppercase()
-            } else {
-                "Unknown algorithm".to_string()
-            };
-            eprintln!(
-                "{}: {}: {}: improperly formatted {} checksum line",
-                util_name(),
-                &filename_input.maybe_quote(),
-                i + 1,
-                algo
-            );
-        }
 
-        Err(LineCheckError::ImproperlyFormatted)
+    if line_info.format == LineFormat::AlgoBased {
+        process_algo_based_line(&line_info, cli_algo_name, opts, last_algo)
+    } else if let Some(cli_algo) = cli_algo_name {
+        // If we match a non-algo based regex, we expect a cli argument
+        // to give us the algorithm to use
+        process_non_algo_based_line(i, &line_info, cli_algo, cli_algo_length, opts)
+    } else {
+        // We have no clue of what algorithm to use
+        return Err(LineCheckError::ImproperlyFormatted);
     }
 }
 
@@ -856,7 +885,6 @@ fn process_checksum_file(
             Err(e) => {
                 // Could not read the file, show the error and continue to the next file
                 show_error!("{e}");
-                set_exit_code(1);
                 return Err(FileCheckError::CantOpenChecksumFile);
             }
         }
@@ -868,16 +896,20 @@ fn process_checksum_file(
     // cached_regex is used to ensure that several non algo-based checksum line
     // will use the same regex.
     let mut cached_regex = None;
+    // last_algo caches the algorithm used in the last line to print a warning
+    // message for the current line if improperly formatted.
+    // Behavior tested in gnu_cksum_c::test_warn
+    let mut last_algo = None;
 
     for (i, line) in lines.iter().enumerate() {
         let line_result = process_checksum_line(
-            filename_input,
             line,
             i,
             cli_algo_name,
             cli_algo_length,
             opts,
             &mut cached_regex,
+            &mut last_algo,
         );
 
         // Match a first time to elude critical UErrors, and increment the total
@@ -893,7 +925,26 @@ fn process_checksum_file(
         match line_result {
             Ok(()) => res.correct += 1,
             Err(DigestMismatch) => res.failed_cksum += 1,
-            Err(ImproperlyFormatted) => res.bad_format += 1,
+            Err(ImproperlyFormatted) => {
+                res.bad_format += 1;
+
+                if opts.verbose.at_least_warning() {
+                    let algo = if let Some(algo_name_input) = cli_algo_name {
+                        Cow::Owned(algo_name_input.to_uppercase())
+                    } else if let Some(algo) = &last_algo {
+                        Cow::Borrowed(algo.as_str())
+                    } else {
+                        Cow::Borrowed("Unknown algorithm")
+                    };
+                    eprintln!(
+                        "{}: {}: {}: improperly formatted {} checksum line",
+                        util_name(),
+                        &filename_input.maybe_quote(),
+                        i + 1,
+                        algo
+                    );
+                }
+            }
             Err(CantOpenFile | FileIsDirectory) => res.failed_open_file += 1,
             Err(FileNotFound) if !opts.ignore_missing => res.failed_open_file += 1,
             _ => continue,
@@ -903,36 +954,43 @@ fn process_checksum_file(
     // not a single line correctly formatted found
     // return an error
     if res.total_properly_formatted() == 0 {
-        if !opts.status {
+        if opts.verbose.over_status() {
             log_no_properly_formatted(get_filename_for_output(filename_input, input_is_stdin));
         }
-        set_exit_code(1);
+        return Err(FileCheckError::Failed);
-        return Err(FileCheckError::ImproperlyFormatted);
     }
 
     // if any incorrectly formatted line, show it
-    cksum_output(&res, opts.status);
+    if opts.verbose.over_status() {
+        print_cksum_report(&res);
+    }
 
     if opts.ignore_missing && res.correct == 0 {
         // we have only bad format
         // and we had ignore-missing
-        eprintln!(
+        if opts.verbose.over_status() {
-            "{}: {}: no file was verified",
+            eprintln!(
-            util_name(),
+                "{}: {}: no file was verified",
-            filename_input.maybe_quote(),
+                util_name(),
-        );
+                filename_input.maybe_quote(),
-        set_exit_code(1);
+            );
+        }
+        return Err(FileCheckError::Failed);
     }
 
     // strict means that we should have an exit code.
     if opts.strict && res.bad_format > 0 {
-        set_exit_code(1);
+        return Err(FileCheckError::Failed);
     }
 
-    // if we have any failed checksum verification, we set an exit code
+    // If a file was missing, return an error unless we explicitly ignore it.
-    // except if we have ignore_missing
+    if res.failed_open_file > 0 && !opts.ignore_missing {
-    if (res.failed_cksum > 0 || res.failed_open_file > 0) && !opts.ignore_missing {
+        return Err(FileCheckError::Failed);
-        set_exit_code(1);
+    }
+
+    // Obviously, if a checksum failed at some point, report the error.
+    if res.failed_cksum > 0 {
+        return Err(FileCheckError::Failed);
     }
 
     Ok(())
@@ -950,16 +1008,23 @@ pub fn perform_checksum_validation<'a, I>(
 where
     I: Iterator<Item = &'a OsStr>,
 {
+    let mut failed = false;
+
     // if cksum has several input files, it will print the result for each file
     for filename_input in files {
         use FileCheckError::*;
         match process_checksum_file(filename_input, algo_name_input, length_input, opts) {
             Err(UError(e)) => return Err(e),
-            Err(CantOpenChecksumFile | ImproperlyFormatted) | Ok(_) => continue,
+            Err(Failed | CantOpenChecksumFile) => failed = true,
+            Ok(_) => continue,
         }
     }
 
-    Ok(())
+    if failed {
+        Err(USimpleError::new(1, ""))
+    } else {
+        Ok(())
+    }
 }
 
 pub fn digest_reader<T: Read>(
@@ -1416,7 +1481,7 @@ mod tests {
 
         for (filename, result, prefix, expected) in cases {
             let mut buffer: Vec<u8> = vec![];
-            print_file_report(&mut buffer, filename, *result, prefix, opts);
+            print_file_report(&mut buffer, filename, *result, prefix, opts.verbose);
             assert_eq!(&buffer, expected)
         }
     }

tests/by-util/test_cksum.rs

@@ -2,7 +2,7 @@
 //
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
-// spell-checker:ignore (words) asdf algo algos asha mgmt xffname hexa GFYEQ HYQK Yqxb
+// spell-checker:ignore (words) asdf algo algos asha mgmt xffname hexa GFYEQ HYQK Yqxb dont
 
 use crate::common::util::TestScenario;
 
@@ -1284,6 +1284,18 @@ fn test_several_files_error_mgmt() {
         .stderr_contains("incorrect: no properly ");
 }
 
+#[test]
+fn test_check_unknown_checksum_file() {
+    let scene = TestScenario::new(util_name!());
+
+    scene
+        .ucmd()
+        .arg("--check")
+        .arg("missing")
+        .fails()
+        .stderr_only("cksum: missing: No such file or directory\n");
+}
+
 #[test]
 fn test_check_comment_line() {
     // A comment in a checksum file shall be discarded unnoticed.
@@ -1811,6 +1823,373 @@ mod gnu_cksum_base64 {
     }
 }
 
+/// This module reimplements the cksum-c.sh GNU test.
+mod gnu_cksum_c {
+    use super::*;
+
+    const INVALID_SUM: &str = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaafdb57c725157cb40b5aee8d937b8351477e";
+
+    fn make_scene() -> TestScenario {
+        let scene = TestScenario::new(util_name!());
+        let at = &scene.fixtures;
+        at.write("input", "9\n7\n1\n4\n2\n6\n3\n5\n8\n10\n");
+
+        let algos: &[&[&str]] = &[
+            &["-a", "sha384"],
+            &["-a", "blake2b"],
+            &["-a", "blake2b", "-l", "384"],
+            &["-a", "sm3"],
+        ];
+
+        for args in algos {
+            let result = scene.ucmd().args(args).succeeds();
+            let stdout = result.stdout();
+            at.append_bytes("CHECKSUMS", stdout);
+        }
+
+        scene
+    }
+
+    #[test]
+    #[ignore]
+    fn test_signed_checksums() {
+        todo!()
+    }
+
+    #[test]
+    fn test_check_individual_digests_in_mixed_file() {
+        let scene = make_scene();
+
+        scene
+            .ucmd()
+            .arg("--check")
+            .arg("-a")
+            .arg("sm3")
+            .arg("CHECKSUMS")
+            .succeeds();
+    }
+
+    #[test]
+    fn test_check_against_older_non_hex_formats() {
+        let scene = make_scene();
+
+        scene
+            .ucmd()
+            .arg("-c")
+            .arg("-a")
+            .arg("crc")
+            .arg("CHECKSUMS")
+            .fails();
+
+        let crc_cmd = scene.ucmd().arg("-a").arg("crc").arg("input").succeeds();
+        let crc_cmd_out = crc_cmd.stdout();
+        scene.fixtures.write_bytes("CHECKSUMS.crc", crc_cmd_out);
+
+        scene.ucmd().arg("-c").arg("CHECKSUMS.crc").fails();
+    }
+
+    #[test]
+    fn test_status() {
+        let scene = make_scene();
+
+        scene
+            .ucmd()
+            .arg("--status")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .succeeds()
+            .no_output();
+    }
+
+    fn make_scene_with_comment() -> TestScenario {
+        let scene = make_scene();
+
+        scene
+            .fixtures
+            .append("CHECKSUMS", "# Very important comment\n");
+
+        scene
+    }
+
+    #[test]
+    fn test_status_with_comment() {
+        let scene = make_scene_with_comment();
+
+        scene
+            .ucmd()
+            .arg("--status")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .succeeds()
+            .no_output();
+    }
+
+    fn make_scene_with_invalid_line() -> TestScenario {
+        let scene = make_scene_with_comment();
+
+        scene.fixtures.append("CHECKSUMS", "invalid_line\n");
+
+        scene
+    }
+
+    #[test]
+    fn test_check_strict() {
+        let scene = make_scene_with_invalid_line();
+
+        // without strict, succeeds
+        scene
+            .ucmd()
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .succeeds()
+            .stderr_contains("1 line is improperly formatted");
+
+        // with strict, fails
+        scene
+            .ucmd()
+            .arg("--strict")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .stderr_contains("1 line is improperly formatted");
+    }
+
+    fn make_scene_with_two_invalid_lines() -> TestScenario {
+        let scene = make_scene_with_comment();
+
+        scene
+            .fixtures
+            .append("CHECKSUMS", "invalid_line\ninvalid_line\n");
+
+        scene
+    }
+
+    #[test]
+    fn test_check_strict_plural_checks() {
+        let scene = make_scene_with_two_invalid_lines();
+
+        scene
+            .ucmd()
+            .arg("--strict")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .stderr_contains("2 lines are improperly formatted");
+    }
+
+    fn make_scene_with_incorrect_checksum() -> TestScenario {
+        let scene = make_scene_with_two_invalid_lines();
+
+        scene
+            .fixtures
+            .append("CHECKSUMS", &format!("SM3 (input) = {INVALID_SUM}\n"));
+
+        scene
+    }
+
+    #[test]
+    fn test_check_with_incorrect_checksum() {
+        let scene = make_scene_with_incorrect_checksum();
+
+        scene
+            .ucmd()
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .stdout_contains("input: FAILED")
+            .stderr_contains("1 computed checksum did NOT match");
+
+        // also fails with strict
+        scene
+            .ucmd()
+            .arg("--strict")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .stdout_contains("input: FAILED")
+            .stderr_contains("1 computed checksum did NOT match");
+    }
+
+    #[test]
+    fn test_status_with_errors() {
+        let scene = make_scene_with_incorrect_checksum();
+
+        scene
+            .ucmd()
+            .arg("--status")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .no_output();
+    }
+
+    #[test]
+    fn test_check_with_non_existing_file() {
+        let scene = make_scene();
+        scene
+            .fixtures
+            .write("CHECKSUMS2", &format!("SM3 (input2) = {INVALID_SUM}\n"));
+
+        scene
+            .ucmd()
+            .arg("--check")
+            .arg("CHECKSUMS2")
+            .fails()
+            .stdout_contains("input2: FAILED open or read")
+            .stderr_contains("1 listed file could not be read");
+
+        // also fails with strict
+        scene
+            .ucmd()
+            .arg("--strict")
+            .arg("--check")
+            .arg("CHECKSUMS2")
+            .fails()
+            .stdout_contains("input2: FAILED open or read")
+            .stderr_contains("1 listed file could not be read");
+    }
+
+    fn make_scene_with_another_improperly_formatted() -> TestScenario {
+        let scene = make_scene_with_incorrect_checksum();
+
+        scene.fixtures.append(
+            "CHECKSUMS",
+            &format!("BLAKE2b (missing-file) = {INVALID_SUM}\n"),
+        );
+
+        scene
+    }
+
+    #[test]
+    fn test_warn() {
+        let scene = make_scene_with_another_improperly_formatted();
+
+        scene
+            .ucmd()
+            .arg("--warn")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .run()
+            .stderr_contains("CHECKSUMS: 6: improperly formatted SM3 checksum line")
+            .stderr_contains("CHECKSUMS: 9: improperly formatted BLAKE2b checksum line");
+    }
+
+    fn make_scene_with_checksum_missing() -> TestScenario {
+        let scene = make_scene_with_another_improperly_formatted();
+
+        scene.fixtures.write(
+            "CHECKSUMS-missing",
+            &format!("SM3 (nonexistent) = {INVALID_SUM}\n"),
+        );
+
+        scene
+    }
+
+    #[test]
+    fn test_ignore_missing() {
+        let scene = make_scene_with_checksum_missing();
+
+        scene
+            .ucmd()
+            .arg("--ignore-missing")
+            .arg("--check")
+            .arg("CHECKSUMS-missing")
+            .fails()
+            .stdout_does_not_contain("nonexistent: No such file or directory")
+            .stdout_does_not_contain("nonexistent: FAILED open or read")
+            .stderr_contains("CHECKSUMS-missing: no file was verified");
+    }
+
+    #[test]
+    fn test_status_and_warn() {
+        let scene = make_scene_with_checksum_missing();
+
+        // --status before --warn
+        scene
+            .ucmd()
+            .arg("--status")
+            .arg("--warn")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .stderr_contains("CHECKSUMS: 9: improperly formatted BLAKE2b checksum line")
+            .stderr_contains("WARNING: 3 lines are improperly formatted")
+            .stderr_contains("WARNING: 1 computed checksum did NOT match");
+
+        // --warn before --status (status hides the results)
+        scene
+            .ucmd()
+            .arg("--warn")
+            .arg("--status")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .stderr_does_not_contain("CHECKSUMS: 9: improperly formatted BLAKE2b checksum line")
+            .stderr_does_not_contain("WARNING: 3 lines are improperly formatted")
+            .stderr_does_not_contain("WARNING: 1 computed checksum did NOT match");
+    }
+
+    #[test]
+    fn test_status_and_ignore_missing() {
+        let scene = make_scene_with_checksum_missing();
+
+        scene
+            .ucmd()
+            .arg("--status")
+            .arg("--ignore-missing")
+            .arg("--check")
+            .arg("CHECKSUMS")
+            .fails()
+            .no_output();
+    }
+
+    #[test]
+    fn test_status_warn_and_ignore_missing() {
+        let scene = make_scene_with_checksum_missing();
+
+        scene
+            .ucmd()
+            .arg("--status")
+            .arg("--warn")
+            .arg("--ignore-missing")
+            .arg("--check")
+            .arg("CHECKSUMS-missing")
+            .fails()
+            .stderr_contains("CHECKSUMS-missing: no file was verified")
+            .stdout_does_not_contain("nonexistent: No such file or directory");
+    }
+
+    #[test]
+    fn test_check_several_files_dont_exist() {
+        let scene = make_scene();
+
+        scene
+            .ucmd()
+            .arg("--check")
+            .arg("non-existing-1")
+            .arg("non-existing-2")
+            .fails()
+            .stderr_contains("non-existing-1: No such file or directory")
+            .stderr_contains("non-existing-2: No such file or directory");
+    }
+
+    #[test]
+    fn test_check_several_files_empty() {
+        let scene = make_scene();
+        scene.fixtures.touch("empty-1");
+        scene.fixtures.touch("empty-2");
+
+        scene
+            .ucmd()
+            .arg("--check")
+            .arg("empty-1")
+            .arg("empty-2")
+            .fails()
+            .stderr_contains("empty-1: no properly formatted checksum lines found")
+            .stderr_contains("empty-2: no properly formatted checksum lines found");
+    }
+}
+
 /// The tests in this module check the behavior of cksum when given different
 /// checksum formats and algorithms in the same file, while specifying an
 /// algorithm on CLI or not.