shuf: use UResult

src/uu/shuf/src/shuf.rs

@@ -7,14 +7,12 @@
 
 // spell-checker:ignore (ToDO) cmdline evec seps rvec fdata
 
-#[macro_use]
-extern crate uucore;
-
 use clap::{crate_version, App, Arg};
 use rand::Rng;
 use std::fs::File;
 use std::io::{stdin, stdout, BufReader, BufWriter, Read, Write};
 use uucore::display::Quotable;
+use uucore::error::{FromIo, UResult, USimpleError};
 use uucore::InvalidEncodingHandling;
 
 enum Mode {
@@ -52,7 +50,8 @@ mod options {
     pub static FILE: &str = "file";
 }
 
-pub fn uumain(args: impl uucore::Args) -> i32 {
+#[uucore_procs::gen_uumain]
+pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let args = args
         .collect_str(InvalidEncodingHandling::ConvertLossy)
         .accept_any();
@@ -65,7 +64,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         match parse_range(range) {
             Ok(m) => Mode::InputRange(m),
             Err(msg) => {
-                crash!(1, "{}", msg);
+                return Err(USimpleError::new(1, msg));
             }
         }
     } else {
@@ -77,8 +76,10 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
             Some(count) => match count.parse::<usize>() {
                 Ok(val) => val,
                 Err(_) => {
-                    show_error!("invalid line count: {}", count.quote());
-                    return 1;
+                    return Err(USimpleError::new(
+                        1,
+                        format!("invalid line count: {}", count.quote()),
+                    ));
                 }
             },
             None => std::usize::MAX,
@@ -97,22 +98,22 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         Mode::Echo(args) => {
             let mut evec = args.iter().map(String::as_bytes).collect::<Vec<_>>();
             find_seps(&mut evec, options.sep);
-            shuf_bytes(&mut evec, options);
+            shuf_bytes(&mut evec, options)?;
         }
         Mode::InputRange((b, e)) => {
             let rvec = (b..e).map(|x| format!("{}", x)).collect::<Vec<String>>();
             let mut rvec = rvec.iter().map(String::as_bytes).collect::<Vec<&[u8]>>();
-            shuf_bytes(&mut rvec, options);
+            shuf_bytes(&mut rvec, options)?;
         }
         Mode::Default(filename) => {
-            let fdata = read_input_file(&filename);
+            let fdata = read_input_file(&filename)?;
             let mut fdata = vec![&fdata[..]];
             find_seps(&mut fdata, options.sep);
-            shuf_bytes(&mut fdata, options);
+            shuf_bytes(&mut fdata, options)?;
         }
     }
 
-    0
+    Ok(())
 }
 
 pub fn uu_app() -> App<'static, 'static> {
@@ -180,22 +181,20 @@ pub fn uu_app() -> App<'static, 'static> {
         .arg(Arg::with_name(options::FILE).takes_value(true))
 }
 
-fn read_input_file(filename: &str) -> Vec<u8> {
+fn read_input_file(filename: &str) -> UResult<Vec<u8>> {
     let mut file = BufReader::new(if filename == "-" {
         Box::new(stdin()) as Box<dyn Read>
     } else {
-        match File::open(filename) {
-            Ok(f) => Box::new(f) as Box<dyn Read>,
-            Err(e) => crash!(1, "failed to open {}: {}", filename.quote(), e),
-        }
+        let file = File::open(filename)
+            .map_err_context(|| format!("failed to open {}", filename.quote()))?;
+        Box::new(file) as Box<dyn Read>
     });
 
     let mut data = Vec::new();
-    if let Err(e) = file.read_to_end(&mut data) {
-        crash!(1, "failed reading {}: {}", filename.quote(), e)
-    };
+    file.read_to_end(&mut data)
+        .map_err_context(|| format!("failed reading {}", filename.quote()))?;
 
-    data
+    Ok(data)
 }
 
 fn find_seps(data: &mut Vec<&[u8]>, sep: u8) {
@@ -231,22 +230,22 @@ fn find_seps(data: &mut Vec<&[u8]>, sep: u8) {
     }
 }
 
-fn shuf_bytes(input: &mut Vec<&[u8]>, opts: Options) {
+fn shuf_bytes(input: &mut Vec<&[u8]>, opts: Options) -> UResult<()> {
     let mut output = BufWriter::new(match opts.output {
         None => Box::new(stdout()) as Box<dyn Write>,
-        Some(s) => match File::create(&s[..]) {
-            Ok(f) => Box::new(f) as Box<dyn Write>,
-            Err(e) => crash!(1, "failed to open {} for writing: {}", s.quote(), e),
-        },
+        Some(s) => {
+            let file = File::create(&s[..])
+                .map_err_context(|| format!("failed to open {} for writing", s.quote()))?;
+            Box::new(file) as Box<dyn Write>
+        }
     });
 
     let mut rng = match opts.random_source {
-        Some(r) => WrappedRng::RngFile(rand::rngs::adapter::ReadRng::new(
-            match File::open(&r[..]) {
-                Ok(f) => f,
-                Err(e) => crash!(1, "failed to open random source {}: {}", r.quote(), e),
-            },
-        )),
+        Some(r) => {
+            let file = File::open(&r[..])
+                .map_err_context(|| format!("failed to open random source {}", r.quote()))?;
+            WrappedRng::RngFile(rand::rngs::adapter::ReadRng::new(file))
+        }
         None => WrappedRng::RngDefault(rand::thread_rng()),
     };
 
@@ -268,10 +267,10 @@ fn shuf_bytes(input: &mut Vec<&[u8]>, opts: Options) {
         // write the randomly chosen value and the separator
         output
             .write_all(input[r])
-            .unwrap_or_else(|e| crash!(1, "write failed: {}", e));
+            .map_err_context(|| "write failed".to_string())?;
         output
             .write_all(&[opts.sep])
-            .unwrap_or_else(|e| crash!(1, "write failed: {}", e));
+            .map_err_context(|| "write failed".to_string())?;
 
         // if we do not allow repeats, remove the chosen value from the input vector
         if !opts.repeat {
@@ -284,6 +283,7 @@ fn shuf_bytes(input: &mut Vec<&[u8]>, opts: Options) {
 
         count -= 1;
     }
+    Ok(())
 }
 
 fn parse_range(input_range: &str) -> Result<(usize, usize), String> {