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

Author: venoosoo

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)]
@@ -105,6 +105,11 @@ pub struct Options {
     /// `--debug`
     pub debug: bool,
 
+    #[doc(hidden)]
+    /// `---presume-input-tty`
+    /// Always use `None`; GNU flag for testing use only
+    pub __presume_input_tty: Option<bool>,
+
     /// `-Z, --context`
     pub context: Option<String>,
 }
@@ -123,6 +128,7 @@ impl Default for Options {
             progress_bar: false,
             debug: false,
             context: None,
+            __presume_input_tty: None,
         }
     }
 }
@@ -153,6 +159,8 @@ static ARG_FILES: &str = "files";
 static OPT_DEBUG: &str = "debug";
 static OPT_CONTEXT: &str = "context";
 static OPT_SELINUX: &str = "selinux";
+static PRESUME_INPUT_TTY: &str = "-presume-input-tty";
+
 
 #[uucore::main]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
@@ -220,6 +228,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         progress_bar: matches.get_flag(OPT_PROGRESS),
         debug: matches.get_flag(OPT_DEBUG),
         context,
+        __presume_input_tty: if matches.get_flag(PRESUME_INPUT_TTY) {
+            Some(true)
+        } else {
+            None
+        }
     };
 
     mv(&files[..], &opts)
@@ -333,6 +346,13 @@ pub fn uu_app() -> Command {
                 .help(translate!("mv-help-debug"))
                 .action(ArgAction::SetTrue),
         )
+        .arg(
+            Arg::new(PRESUME_INPUT_TTY)
+                .long("presume-input-tty")
+                .alias(PRESUME_INPUT_TTY)
+                .hide(true)
+                .action(ArgAction::SetTrue),
+        )
 }
 
 fn determine_overwrite_mode(matches: &ArgMatches) -> OverwriteMode {
@@ -427,12 +447,12 @@ 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 +745,13 @@ 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 +1296,14 @@ 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<()> {
+    let stdin_ok = options.__presume_input_tty.unwrap_or(false) || stdin().is_terminal();
+    match (stdin_ok, &options.overwrite) {
+        // stdin is not a terminal and this is just the default protection prompt
+        // skip silently like GNU mv does
+        (false, 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 +18,25 @@ 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);