mv: don't prompt to overwrite read-only file when stdin is not a terminal

src/uu/mv/src/mv.rs

@@ -20,7 +20,7 @@ use rustc_hash::FxHashSet;
 use std::env;
 use std::ffi::OsString;
 use std::fs;
-use std::io::{self, IsTerminal};
+use std::io::{self, IsTerminal, stdin};
 #[cfg(unix)]
 use std::os::unix;
 #[cfg(unix)]
@@ -427,12 +427,12 @@ fn handle_two_paths(source: &Path, target: &Path, opts: &Options) -> UResult<()>
     } else if target.exists() && source_is_dir {
         match opts.overwrite {
             OverwriteMode::NoClobber => return Ok(()),
-            OverwriteMode::Interactive => prompt_overwrite(target, None)?,
+            OverwriteMode::Interactive => prompt_overwrite(target, None, opts)?,
             OverwriteMode::Force => {}
             OverwriteMode::Default => {
                 let (writable, mode) = is_writable(target);
-                if !writable && io::stdin().is_terminal() {
-                    prompt_overwrite(target, mode)?;
+                if !writable && stdin().is_terminal() {
+                    prompt_overwrite(target, mode, opts)?;
                 }
             }
         }
@@ -725,13 +725,13 @@ fn rename(
                 }
                 return Ok(());
             }
-            OverwriteMode::Interactive => prompt_overwrite(to, None)?,
+            OverwriteMode::Interactive => prompt_overwrite(to, None, opts)?,
             OverwriteMode::Force => {}
             OverwriteMode::Default => {
                 // GNU mv prompts when stdin is a TTY and target is not writable
                 let (writable, mode) = is_writable(to);
-                if !writable && io::stdin().is_terminal() {
-                    prompt_overwrite(to, mode)?;
+                if !writable && stdin().is_terminal() {
+                    prompt_overwrite(to, mode, opts)?;
                 }
             }
         }
@@ -1276,7 +1276,12 @@ fn get_interactive_prompt(to: &Path, _cached_mode: Option<u32>) -> String {
 }
 
 /// Prompts the user for confirmation and returns an error if declined.
-fn prompt_overwrite(to: &Path, cached_mode: Option<u32>) -> io::Result<()> {
+fn prompt_overwrite(to: &Path, cached_mode: Option<u32>, options: &Options) -> io::Result<()> {
+    if !stdin().is_terminal() {
+        if options.overwrite == OverwriteMode::Default {
+            return Ok(());
+        }
+    }
     if !prompt_yes!("{}", get_interactive_prompt(to, cached_mode)) {
         return Err(io::Error::other(""));
     }

tests/by-util/test_mv.rs

@@ -18,6 +18,19 @@ use uutests::util::TerminalSimulation;
 use uutests::util::TestScenario;
 use uutests::{at_and_ucmd, util_name};
 
+#[cfg(unix)]
+#[test]
+fn test_mv_no_prompt_when_stdin_not_terminal() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    at.write("target", "original");
+    at.set_mode("target", 0o555);
+    at.write("source", "replacement");
+
+    ucmd.arg("source").arg("target").pipe_in("").succeeds();
+
+    assert_eq!(at.read("target"), "replacement");
+}
+
 #[test]
 fn test_mv_invalid_arg() {
     new_ucmd!().arg("--definitely-invalid").fails_with_code(1);