csplit: return UResult instead of io::Result from iterator to handle error message more uniformly.

src/uu/csplit/src/csplit.rs

@@ -87,7 +87,11 @@ pub fn csplit<T>(options: &CsplitOptions, patterns: &[String], input: T) -> Resu
 where
     T: BufRead,
 {
-    let mut input_iter = InputSplitter::new(input.lines().enumerate());
+    let enumerated_input_lines = input
+        .lines()
+        .map(|line| line.map_err_context(|| "read error".to_string()))
+        .enumerate();
+    let mut input_iter = InputSplitter::new(enumerated_input_lines);
     let mut split_writer = SplitWriter::new(options);
     let patterns: Vec<patterns::Pattern> = patterns::get_patterns(patterns)?;
     let ret = do_csplit(&mut split_writer, patterns, &mut input_iter);
@@ -117,7 +121,7 @@ fn do_csplit<I>(
     input_iter: &mut InputSplitter<I>,
 ) -> Result<(), CsplitError>
 where
-    I: Iterator<Item = (usize, io::Result<String>)>,
+    I: Iterator<Item = (usize, UResult<String>)>,
 {
     // split the file based on patterns
     for pattern in patterns {
@@ -305,7 +309,7 @@ impl SplitWriter<'_> {
         input_iter: &mut InputSplitter<I>,
     ) -> Result<(), CsplitError>
     where
-        I: Iterator<Item = (usize, io::Result<String>)>,
+        I: Iterator<Item = (usize, UResult<String>)>,
     {
         input_iter.rewind_buffer();
         input_iter.set_size_of_buffer(1);
@@ -358,7 +362,7 @@ impl SplitWriter<'_> {
         input_iter: &mut InputSplitter<I>,
     ) -> Result<(), CsplitError>
     where
-        I: Iterator<Item = (usize, io::Result<String>)>,
+        I: Iterator<Item = (usize, UResult<String>)>,
     {
         if offset >= 0 {
             // The offset is zero or positive, no need for a buffer on the lines read.
@@ -470,7 +474,7 @@ impl SplitWriter<'_> {
 /// This is used to pass matching lines to the next split and to support patterns with a negative offset.
 struct InputSplitter<I>
 where
-    I: Iterator<Item = (usize, io::Result<String>)>,
+    I: Iterator<Item = (usize, UResult<String>)>,
 {
     iter: I,
     buffer: Vec<<I as Iterator>::Item>,
@@ -483,7 +487,7 @@ where
 
 impl<I> InputSplitter<I>
 where
-    I: Iterator<Item = (usize, io::Result<String>)>,
+    I: Iterator<Item = (usize, UResult<String>)>,
 {
     fn new(iter: I) -> Self {
         Self {
@@ -547,7 +551,7 @@ where
 
 impl<I> Iterator for InputSplitter<I>
 where
-    I: Iterator<Item = (usize, io::Result<String>)>,
+    I: Iterator<Item = (usize, UResult<String>)>,
 {
     type Item = <I as Iterator>::Item;
 

src/uu/csplit/src/csplit_error.rs

@@ -35,6 +35,8 @@ pub enum CsplitError {
     SuffixFormatTooManyPercents,
     #[error("{} is not a regular file", ._0.quote())]
     NotRegularFile(String),
+    #[error("{}", _0)]
+    UError(Box<dyn UError>),
 }
 
 impl From<io::Error> for CsplitError {
@@ -43,8 +45,17 @@ impl From<io::Error> for CsplitError {
     }
 }
 
-impl UError for CsplitError {
-    fn code(&self) -> i32 {
-        1
+impl From<Box<dyn UError>> for CsplitError {
+    fn from(error: Box<dyn UError>) -> Self {
+        Self::UError(error)
+    }
+}
+
+impl UError for CsplitError {
+    fn code(&self) -> i32 {
+        match self {
+            Self::UError(e) => e.code(),
+            _ => 1,
+        }
     }
 }