env: use UResult everywhere

src/uu/env/src/env.rs

@@ -23,7 +23,7 @@ use std::io::{self, Write};
 use std::iter::Iterator;
 use std::process::Command;
 use uucore::display::Quotable;
-use uucore::error::{UResult, USimpleError};
+use uucore::error::{UResult, USimpleError, UUsageError};
 
 const USAGE: &str = "env [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...]";
 const AFTER_HELP: &str = "\
@@ -50,7 +50,7 @@ fn print_env(null: bool) {
     }
 }
 
-fn parse_name_value_opt<'a>(opts: &mut Options<'a>, opt: &'a str) -> Result<bool, i32> {
+fn parse_name_value_opt<'a>(opts: &mut Options<'a>, opt: &'a str) -> UResult<bool> {
     // is it a NAME=VALUE like opt ?
     if let Some(idx) = opt.find('=') {
         // yes, so push name, value pair
@@ -64,17 +64,12 @@ fn parse_name_value_opt<'a>(opts: &mut Options<'a>, opt: &'a str) -> Result<bool
     }
 }
 
-fn parse_program_opt<'a>(opts: &mut Options<'a>, opt: &'a str) -> Result<(), i32> {
+fn parse_program_opt<'a>(opts: &mut Options<'a>, opt: &'a str) -> UResult<()> {
     if opts.null {
-        eprintln!(
-            "{}: cannot specify --null (-0) with command",
-            uucore::util_name()
-        );
-        eprintln!(
-            "Type \"{} --help\" for detailed information",
-            uucore::execution_phrase()
-        );
-        Err(1)
+        Err(UUsageError::new(
+            125,
+            "cannot specify --null (-0) with command".to_string(),
+        ))
     } else {
         opts.program.push(opt);
         Ok(())
@@ -93,10 +88,8 @@ fn load_config_file(opts: &mut Options) -> UResult<()> {
             Ini::load_from_file(file)
         };
 
-        let conf = conf.map_err(|error| {
-            show_error!("{}: {}", file.maybe_quote(), error);
-            1
-        })?;
+        let conf =
+            conf.map_err(|e| USimpleError::new(1, format!("{}: {}", file.maybe_quote(), e)))?;
 
         for (_, prop) in &conf {
             // ignore all INI section lines (treat them as comments)