hashsum: don't exit early on io errors

src/uu/hashsum/src/hashsum.rs

@@ -33,10 +33,11 @@ const NAME: &str = "hashsum";
 const ABOUT: &str = help_about!("hashsum.md");
 const USAGE: &str = help_usage!("hashsum.md");
 
-struct Options {
+struct Options<'a> {
     algoname: &'static str,
     digest: Box<dyn Digest + 'static>,
     binary: bool,
+    binary_name: &'a str,
     //check: bool,
     tag: bool,
     nonames: bool,
@@ -274,6 +275,7 @@ pub fn uumain(mut args: impl uucore::Args) -> UResult<()> {
         digest: (algo.create_fn)(),
         output_bits: algo.bits,
         binary,
+        binary_name: &binary_name,
         tag: matches.get_flag("tag"),
         nonames,
         //status,
@@ -520,17 +522,25 @@ where
     I: Iterator<Item = &'a OsStr>,
 {
     let binary_marker = if options.binary { "*" } else { " " };
+    let mut err_found = None;
     for filename in files {
         let filename = Path::new(filename);
 
-        let stdin_buf;
-        let file_buf;
         let mut file = BufReader::new(if filename == OsStr::new("-") {
-            stdin_buf = stdin();
-            Box::new(stdin_buf) as Box<dyn Read>
+            Box::new(stdin()) as Box<dyn Read>
         } else {
-            file_buf =
-                File::open(filename).map_err_context(|| "failed to open file".to_string())?;
+            let file_buf = match File::open(filename) {
+                Ok(f) => f,
+                Err(e) => {
+                    eprintln!(
+                        "{}: {}: {e}",
+                        options.binary_name,
+                        filename.to_string_lossy()
+                    );
+                    err_found = Some(ChecksumError::Io(e));
+                    continue;
+                }
+            };
             Box::new(file_buf) as Box<dyn Read>
         });
 
@@ -568,5 +578,8 @@ where
             println!("{prefix}{sum} {binary_marker}{escaped_filename}");
         }
     }
-    Ok(())
+    match err_found {
+        None => Ok(()),
+        Some(e) => Err(Box::new(e)),
+    }
 }

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

@@ -233,6 +233,8 @@ pub enum ChecksumError {
     CombineMultipleAlgorithms,
     #[error("Needs an algorithm to hash with.\nUse --help for more information.")]
     NeedAlgorithmToHash,
+    #[error("")]
+    Io(#[from] io::Error),
 }
 
 impl UError for ChecksumError {

tests/by-util/test_hashsum.rs

@@ -98,6 +98,27 @@ macro_rules! test_digest {
                 .no_stderr()
                 .stdout_is(std::str::from_utf8(&expected).unwrap());
         }
+
+        #[test]
+        fn test_missing_file() {
+            let ts = TestScenario::new("hashsum");
+            let at = &ts.fixtures;
+
+            at.write("a", "file1\n");
+            at.write("c", "file3\n");
+
+            #[cfg(unix)]
+            let file_not_found_str = "No such file or directory";
+            #[cfg(not(unix))]
+            let file_not_found_str = "The system cannot find the file specified";
+
+            ts.ucmd()
+                .args(&[DIGEST_ARG, BITS_ARG, "a", "b", "c"])
+                .fails()
+                .stdout_contains("a\n")
+                .stdout_contains("c\n")
+                .stderr_contains(format!("b: {file_not_found_str}"));
+        }
     }
     )*)
 }