Fix both files can return an error

fuzz/fuzz_targets/fuzz_side.rs

@@ -2,11 +2,10 @@
 #[macro_use]
 extern crate libfuzzer_sys;
 
-use diffutilslib::side_diff;
+use diffutilslib::side_diff::{self, Params};
 
 use std::fs::File;
 use std::io::Write;
-use diffutilslib::params::Params;
 
 fuzz_target!(|x: (Vec<u8>, Vec<u8>, /* usize, usize */ bool)| {
     let (original, new, /* width, tabsize, */ expand) = x;
@@ -22,7 +21,16 @@ fuzz_target!(|x: (Vec<u8>, Vec<u8>, /* usize, usize */ bool)| {
         ..Default::default()
     };
     let mut output_buf = vec![];
-    side_diff::diff(&original, &new, &mut output_buf, &params);
+    side_diff::diff(
+        &original,
+        &new,
+        &mut output_buf,
+        &Params {
+            width: params.width,
+            tabsize: params.tabsize,
+            expand_tabs: params.expand_tabs,
+        },
+    );
     File::create("target/fuzz.file.original")
         .unwrap()
         .write_all(&original)
@@ -39,4 +47,5 @@ fuzz_target!(|x: (Vec<u8>, Vec<u8>, /* usize, usize */ bool)| {
         .unwrap()
         .write_all(&output_buf)
         .unwrap();
-});
+});
+

src/diff.rs

@@ -4,12 +4,10 @@
 // files that was distributed with this source code.
 
 use crate::params::{parse_params, Format};
-use crate::utils::report_failure_to_read_input_file;
+use crate::utils;
 use crate::{context_diff, ed_diff, normal_diff, side_diff, unified_diff};
 use std::env::ArgsOs;
-use std::ffi::OsString;
-use std::fs;
-use std::io::{self, stdout, Read, Write};
+use std::io::{self, stdout, Write};
 use std::iter::Peekable;
 use std::process::{exit, ExitCode};
 
@@ -23,6 +21,7 @@ pub fn main(opts: Peekable<ArgsOs>) -> ExitCode {
         eprintln!("{error}");
         exit(2);
     });
+
     // if from and to are the same file, no need to perform any comparison
     let maybe_report_identical_files = || {
         if params.report_identical_files {
@@ -40,35 +39,16 @@ pub fn main(opts: Peekable<ArgsOs>) -> ExitCode {
         return ExitCode::SUCCESS;
     }
 
-    // read files
-    fn read_file_contents(filepath: &OsString) -> io::Result<Vec<u8>> {
-        if filepath == "-" {
-            let mut content = Vec::new();
-            io::stdin().read_to_end(&mut content).and(Ok(content))
-        } else {
-            fs::read(filepath)
-        }
-    }
-    let mut io_error = false;
-    let from_content = match read_file_contents(&params.from) {
-        Ok(from_content) => from_content,
-        Err(e) => {
-            report_failure_to_read_input_file(&params.executable, &params.from, &e);
-            io_error = true;
-            vec![]
-        }
-    };
-    let to_content = match read_file_contents(&params.to) {
-        Ok(to_content) => to_content,
+    let (from_content, to_content) = match utils::read_both_files(&params.from, &params.to) {
+        Ok(contents) => contents,
         Err(e) => {
-            report_failure_to_read_input_file(&params.executable, &params.to, &e);
-            io_error = true;
-            vec![]
+            eprintln!(
+                "{}",
+                utils::format_failure_to_read_input_files(&params.executable, &e)
+            );
+            return ExitCode::from(2);
         }
     };
-    if io_error {
-        return ExitCode::from(2);
-    }
 
     // run diff
     let result: Vec<u8> = match params.format {
@@ -81,7 +61,16 @@ pub fn main(opts: Peekable<ArgsOs>) -> ExitCode {
         }),
         Format::SideBySide => {
             let mut output = stdout().lock();
-            side_diff::diff(&from_content, &to_content, &mut output, &params)
+            side_diff::diff(
+                &from_content,
+                &to_content,
+                &mut output,
+                &side_diff::Params {
+                    tabsize: params.tabsize,
+                    width: params.width,
+                    expand_tabs: params.expand_tabs,
+                },
+            )
         }
     };
     if params.brief && !result.is_empty() {

src/main.rs

@@ -18,6 +18,7 @@ mod ed_diff;
 mod macros;
 mod normal_diff;
 mod params;
+mod sdiff;
 mod side_diff;
 mod unified_diff;
 mod utils;
@@ -72,6 +73,7 @@ fn main() -> ExitCode {
     match util_name.to_str() {
         Some("diff") => diff::main(args),
         Some("cmp") => cmp::main(args),
+        Some("sdiff") => sdiff::main(args),
         Some(name) => {
             eprintln!("{name}: utility not supported");
             ExitCode::from(2)