mv, cp: add support for --update=none,all,older

src/uu/cp/cp.md

@@ -7,3 +7,19 @@ cp [OPTION]... -t DIRECTORY SOURCE...
 ```
 
 Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.
+
+## After Help
+
+Do not copy a non-directory that has an existing destination with the same or newer modification timestamp;
+instead, silently skip the file without failing. If timestamps are being preserved, the comparison is to the
+source timestamp truncated to the resolutions of the destination file system and of the system calls used to
+update timestamps; this avoids duplicate work if several ‘cp -pu’ commands are executed with the same source
+and destination. This option is ignored if the -n or --no-clobber option is also specified. Also, if
+--preserve=links is also specified (like with ‘cp -au’ for example), that will take precedence; consequently,
+depending on the order that files are processed from the source, newer files in the destination may be replaced,
+to mirror hard links in the source. which gives more control over which existing files in the destination are
+replaced, and its value can be one of the following:
+
+all    This is the default operation when an --update option is not specified, and results in all existing files in the destination being replaced.
+none   This is similar to the --no-clobber option, in that no files in the destination are replaced, but also skipping a file does not induce a failure.
+older  This is the default operation when --update is specified, and results in files being replaced if they’re older than the corresponding source file.

src/uu/cp/src/cp.rs

@@ -40,7 +40,10 @@ use uucore::error::{set_exit_code, UClapError, UError, UResult, UUsageError};
 use uucore::fs::{
     canonicalize, paths_refer_to_same_file, FileInformation, MissingHandling, ResolveMode,
 };
-use uucore::{crash, format_usage, help_about, help_usage, prompt_yes, show_error, show_warning};
+use uucore::update_control::{self, UpdateMode};
+use uucore::{
+    crash, format_usage, help_about, help_section, help_usage, prompt_yes, show_error, show_warning,
+};
 
 use crate::copydir::copy_directory;
 
@@ -224,13 +227,14 @@ pub struct Options {
     recursive: bool,
     backup_suffix: String,
     target_dir: Option<PathBuf>,
-    update: bool,
+    update: UpdateMode,
     verbose: bool,
     progress_bar: bool,
 }
 
 const ABOUT: &str = help_about!("cp.md");
 const USAGE: &str = help_usage!("cp.md");
+const AFTER_HELP: &str = help_section!("after help", "cp.md");
 
 static EXIT_ERR: i32 = 1;
 
@@ -264,7 +268,6 @@ mod options {
     pub const STRIP_TRAILING_SLASHES: &str = "strip-trailing-slashes";
     pub const SYMBOLIC_LINK: &str = "symbolic-link";
     pub const TARGET_DIRECTORY: &str = "target-directory";
-    pub const UPDATE: &str = "update";
     pub const VERBOSE: &str = "verbose";
 }
 
@@ -295,6 +298,7 @@ pub fn uu_app() -> Command {
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
+        .after_help(AFTER_HELP)
         .infer_long_args(true)
         .arg(
             Arg::new(options::TARGET_DIRECTORY)
@@ -393,16 +397,8 @@ pub fn uu_app() -> Command {
         .arg(backup_control::arguments::backup())
         .arg(backup_control::arguments::backup_no_args())
         .arg(backup_control::arguments::suffix())
-        .arg(
-            Arg::new(options::UPDATE)
-                .short('u')
-                .long(options::UPDATE)
-                .help(
-                    "copy only when the SOURCE file is newer than the destination file \
-                    or when the destination file is missing",
-                )
-                .action(ArgAction::SetTrue),
-        )
+        .arg(update_control::arguments::update())
+        .arg(update_control::arguments::update_no_args())
         .arg(
             Arg::new(options::REFLINK)
                 .long(options::REFLINK)
@@ -641,7 +637,11 @@ impl CopyMode {
             Self::Link
         } else if matches.get_flag(options::SYMBOLIC_LINK) {
             Self::SymLink
-        } else if matches.get_flag(options::UPDATE) {
+        } else if matches
+            .get_one::<String>(update_control::arguments::OPT_UPDATE)
+            .is_some()
+            || matches.get_flag(update_control::arguments::OPT_UPDATE_NO_ARG)
+        {
             Self::Update
         } else if matches.get_flag(options::ATTRIBUTES_ONLY) {
             Self::AttrOnly
@@ -749,6 +749,7 @@ impl Options {
             Err(e) => return Err(Error::Backup(format!("{e}"))),
             Ok(mode) => mode,
         };
+        let update_mode = update_control::determine_update_mode(matches);
 
         let backup_suffix = backup_control::determine_backup_suffix(matches);
 
@@ -826,7 +827,7 @@ impl Options {
                 || matches.get_flag(options::DEREFERENCE),
             one_file_system: matches.get_flag(options::ONE_FILE_SYSTEM),
             parents: matches.get_flag(options::PARENTS),
-            update: matches.get_flag(options::UPDATE),
+            update: update_mode,
             verbose: matches.get_flag(options::VERBOSE),
             strip_trailing_slashes: matches.get_flag(options::STRIP_TRAILING_SLASHES),
             reflink_mode: {
@@ -1473,7 +1474,9 @@ fn copy_file(
     symlinked_files: &mut HashSet<FileInformation>,
     source_in_command_line: bool,
 ) -> CopyResult<()> {
-    if options.update && options.overwrite == OverwriteMode::Interactive(ClobberMode::Standard) {
+    if (options.update == UpdateMode::ReplaceIfOlder || options.update == UpdateMode::ReplaceNone)
+        && options.overwrite == OverwriteMode::Interactive(ClobberMode::Standard)
+    {
         // `cp -i --update old new` when `new` exists doesn't copy anything
         // and exit with 0
         return Ok(());
@@ -1629,22 +1632,38 @@ fn copy_file(
         }
         CopyMode::Update => {
             if dest.exists() {
-                let dest_metadata = fs::symlink_metadata(dest)?;
-
-                let src_time = source_metadata.modified()?;
-                let dest_time = dest_metadata.modified()?;
-                if src_time <= dest_time {
-                    return Ok(());
-                } else {
-                    copy_helper(
-                        source,
-                        dest,
-                        options,
-                        context,
-                        source_is_symlink,
-                        source_is_fifo,
-                        symlinked_files,
-                    )?;
+                match options.update {
+                    update_control::UpdateMode::ReplaceAll => {
+                        copy_helper(
+                            source,
+                            dest,
+                            options,
+                            context,
+                            source_is_symlink,
+                            source_is_fifo,
+                            symlinked_files,
+                        )?;
+                    }
+                    update_control::UpdateMode::ReplaceNone => return Ok(()),
+                    update_control::UpdateMode::ReplaceIfOlder => {
+                        let dest_metadata = fs::symlink_metadata(dest)?;
+
+                        let src_time = source_metadata.modified()?;
+                        let dest_time = dest_metadata.modified()?;
+                        if src_time <= dest_time {
+                            return Ok(());
+                        } else {
+                            copy_helper(
+                                source,
+                                dest,
+                                options,
+                                context,
+                                source_is_symlink,
+                                source_is_fifo,
+                                symlinked_files,
+                            )?;
+                        }
+                    }
                 }
             } else {
                 copy_helper(

src/uu/mv/mv.md

@@ -5,5 +5,17 @@ mv [OPTION]... [-T] SOURCE DEST
 mv [OPTION]... SOURCE... DIRECTORY
 mv [OPTION]... -t DIRECTORY SOURCE...
 ```
-
 Move `SOURCE` to `DEST`, or multiple `SOURCE`(s) to `DIRECTORY`.
+
+## After Help
+
+Do not move a non-directory that has an existing destination with the same or newer modification timestamp;
+instead, silently skip the file without failing. If the move is across file system boundaries, the comparison is
+to the source timestamp truncated to the resolutions of the destination file system and of the system calls used
+to update timestamps; this avoids duplicate work if several ‘mv -u’ commands are executed with the same source
+and destination. This option is ignored if the -n or --no-clobber option is also specified. which gives more control
+over which existing files in the destination are replaced, and its value can be one of the following:
+
+all    This is the default operation when an --update option is not specified, and results in all existing files in the destination being replaced.
+none   This is similar to the --no-clobber option, in that no files in the destination are replaced, but also skipping a file does not induce a failure.
+older  This is the default operation when --update is specified, and results in files being replaced if they’re older than the corresponding source file.

src/uu/mv/src/mv.rs

@@ -25,7 +25,8 @@ use std::path::{Path, PathBuf};
 use uucore::backup_control::{self, BackupMode};
 use uucore::display::Quotable;
 use uucore::error::{set_exit_code, FromIo, UError, UResult, USimpleError, UUsageError};
-use uucore::{format_usage, help_about, help_usage, prompt_yes, show};
+use uucore::update_control::{self, UpdateMode};
+use uucore::{format_usage, help_about, help_section, help_usage, prompt_yes, show};
 
 use fs_extra::dir::{
     get_size as dir_get_size, move_dir, move_dir_with_progress, CopyOptions as DirCopyOptions,
@@ -38,7 +39,7 @@ pub struct Behavior {
     overwrite: OverwriteMode,
     backup: BackupMode,
     suffix: String,
-    update: bool,
+    update: UpdateMode,
     target_dir: Option<OsString>,
     no_target_dir: bool,
     verbose: bool,
@@ -55,14 +56,14 @@ pub enum OverwriteMode {
 
 const ABOUT: &str = help_about!("mv.md");
 const USAGE: &str = help_usage!("mv.md");
+const AFTER_HELP: &str = help_section!("after help", "mv.md");
 
 static OPT_FORCE: &str = "force";
 static OPT_INTERACTIVE: &str = "interactive";
 static OPT_NO_CLOBBER: &str = "no-clobber";
 static OPT_STRIP_TRAILING_SLASHES: &str = "strip-trailing-slashes";
 static OPT_TARGET_DIRECTORY: &str = "target-directory";
 static OPT_NO_TARGET_DIRECTORY: &str = "no-target-directory";
-static OPT_UPDATE: &str = "update";
 static OPT_VERBOSE: &str = "verbose";
 static OPT_PROGRESS: &str = "progress";
 static ARG_FILES: &str = "files";
@@ -96,6 +97,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
 
     let overwrite_mode = determine_overwrite_mode(&matches);
     let backup_mode = backup_control::determine_backup_mode(&matches)?;
+    let update_mode = update_control::determine_update_mode(&matches);
 
     if overwrite_mode == OverwriteMode::NoClobber && backup_mode != BackupMode::NoBackup {
         return Err(UUsageError::new(
@@ -120,7 +122,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         overwrite: overwrite_mode,
         backup: backup_mode,
         suffix: backup_suffix,
-        update: matches.get_flag(OPT_UPDATE),
+        update: update_mode,
         target_dir,
         no_target_dir: matches.get_flag(OPT_NO_TARGET_DIRECTORY),
         verbose: matches.get_flag(OPT_VERBOSE),
@@ -136,9 +138,8 @@ pub fn uu_app() -> Command {
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
+        .after_help(AFTER_HELP)
         .infer_long_args(true)
-        .arg(backup_control::arguments::backup())
-        .arg(backup_control::arguments::backup_no_args())
         .arg(
             Arg::new(OPT_FORCE)
                 .short('f')
@@ -166,7 +167,11 @@ pub fn uu_app() -> Command {
                 .help("remove any trailing slashes from each SOURCE argument")
                 .action(ArgAction::SetTrue),
         )
+        .arg(backup_control::arguments::backup())
+        .arg(backup_control::arguments::backup_no_args())
         .arg(backup_control::arguments::suffix())
+        .arg(update_control::arguments::update())
+        .arg(update_control::arguments::update_no_args())
         .arg(
             Arg::new(OPT_TARGET_DIRECTORY)
                 .short('t')
@@ -184,16 +189,6 @@ pub fn uu_app() -> Command {
                 .help("treat DEST as a normal file")
                 .action(ArgAction::SetTrue),
         )
-        .arg(
-            Arg::new(OPT_UPDATE)
-                .short('u')
-                .long(OPT_UPDATE)
-                .help(
-                    "move only when the SOURCE file is newer than the destination file \
-                       or when the destination file is missing",
-                )
-                .action(ArgAction::SetTrue),
-        )
         .arg(
             Arg::new(OPT_VERBOSE)
                 .short('v')
@@ -420,12 +415,24 @@ fn rename(
     let mut backup_path = None;
 
     if to.exists() {
-        if b.update && b.overwrite == OverwriteMode::Interactive {
+        if (b.update == UpdateMode::ReplaceIfOlder || b.update == UpdateMode::ReplaceNone)
+            && b.overwrite == OverwriteMode::Interactive
+        {
             // `mv -i --update old new` when `new` exists doesn't move anything
             // and exit with 0
             return Ok(());
         }
 
+        if b.update == UpdateMode::ReplaceNone {
+            return Ok(());
+        }
+
+        if (b.update == UpdateMode::ReplaceIfOlder)
+            && fs::metadata(from)?.modified()? <= fs::metadata(to)?.modified()?
+        {
+            return Ok(());
+        }
+
         match b.overwrite {
             OverwriteMode::NoClobber => {
                 return Err(io::Error::new(
@@ -445,10 +452,6 @@ fn rename(
         if let Some(ref backup_path) = backup_path {
             rename_with_fallback(to, backup_path, multi_progress)?;
         }
-
-        if b.update && fs::metadata(from)?.modified()? <= fs::metadata(to)?.modified()? {
-            return Ok(());
-        }
     }
 
     // "to" may no longer exist if it was backed up

src/uucore/src/lib/lib.rs

@@ -26,6 +26,7 @@ pub use crate::mods::os;
 pub use crate::mods::panic;
 pub use crate::mods::quoting_style;
 pub use crate::mods::ranges;
+pub use crate::mods::update_control;
 pub use crate::mods::version_cmp;
 
 // * string parsing modules

src/uucore/src/lib/mods.rs

@@ -6,6 +6,7 @@ pub mod error;
 pub mod os;
 pub mod panic;
 pub mod ranges;
+pub mod update_control;
 pub mod version_cmp;
 // dir and vdir also need access to the quoting_style module
 pub mod quoting_style;

src/uucore/src/lib/mods/update_control.rs

@@ -0,0 +1,55 @@
+use clap::ArgMatches;
+
+pub static UPDATE_CONTROL_VALUES: &[&str] = &["all", "none", "old", ""];
+
+#[derive(Clone, Eq, PartialEq)]
+pub enum UpdateMode {
+    ReplaceAll,
+    ReplaceNone,
+    ReplaceIfOlder,
+}
+
+pub mod arguments {
+    use clap::ArgAction;
+
+    pub static OPT_UPDATE: &str = "update";
+    pub static OPT_UPDATE_NO_ARG: &str = "u";
+
+    pub fn update() -> clap::Arg {
+        clap::Arg::new(OPT_UPDATE)
+            .long("update")
+            .help("move only when the SOURCE file is newer than the destination file or when the destination file is missing")
+            .value_parser(["", "none", "all", "older"])
+            .num_args(0..=1)
+            .default_missing_value("older")
+            .require_equals(true)
+            .overrides_with("update")
+            .action(clap::ArgAction::Set)
+    }
+
+    pub fn update_no_args() -> clap::Arg {
+        clap::Arg::new(OPT_UPDATE_NO_ARG)
+            .short('u')
+            .help("like --update but does not accept an argument")
+            .action(ArgAction::SetTrue)
+    }
+}
+
+pub fn determine_update_mode(matches: &ArgMatches) -> UpdateMode {
+    if matches.contains_id(arguments::OPT_UPDATE) {
+        if let Some(mode) = matches.get_one::<String>(arguments::OPT_UPDATE) {
+            match mode.as_str() {
+                "all" | "" => UpdateMode::ReplaceAll,
+                "none" => UpdateMode::ReplaceNone,
+                "older" => UpdateMode::ReplaceIfOlder,
+                _ => unreachable!("other args restricted by clap"),
+            }
+        } else {
+            unreachable!("other args restricted by clap")
+        }
+    } else if matches.get_flag(arguments::OPT_UPDATE_NO_ARG) {
+        UpdateMode::ReplaceIfOlder
+    } else {
+        UpdateMode::ReplaceAll
+    }
+}