install: Implement --preserve-timestamps (-p)

Last access and last modify timestamps are extracted from the
existing file metadata and are applied to the newly created file.

src/uu/install/Cargo.toml

@@ -19,6 +19,7 @@ path = "src/install.rs"
 
 [dependencies]
 clap = "2.33"
+filetime = "0.2"
 libc = ">= 0.2"
 uucore = { version=">=0.0.7", package="uucore", path="../../uucore", features=["mode", "perms", "entries"] }
 uucore_procs = { version=">=0.0.5", package="uucore_procs", path="../../uucore_procs" }

src/uu/install/src/install.rs

@@ -13,6 +13,7 @@ mod mode;
 extern crate uucore;
 
 use clap::{App, Arg, ArgMatches};
+use filetime::{FileTime, set_file_times};
 use uucore::entries::{grp2gid, usr2uid};
 use uucore::perms::{wrap_chgrp, wrap_chown, Verbosity};
 
@@ -32,6 +33,7 @@ pub struct Behavior {
     owner: String,
     group: String,
     verbose: bool,
+    preserve_timestamps: bool,
 }
 
 #[derive(Clone, Eq, PartialEq)]
@@ -154,11 +156,10 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
                 .takes_value(true)
         )
         .arg(
-            // TODO implement flag
             Arg::with_name(OPT_PRESERVE_TIMESTAMPS)
                 .short("p")
                 .long(OPT_PRESERVE_TIMESTAMPS)
-                .help("(unimplemented) apply access/modification times of SOURCE files to corresponding destination files")
+                .help("apply access/modification times of SOURCE files to corresponding destination files")
         )
         .arg(
             // TODO implement flag
@@ -265,8 +266,6 @@ fn check_unimplemented<'a>(matches: &ArgMatches) -> Result<(), &'a str> {
         Err("--compare, -C")
     } else if matches.is_present(OPT_CREATED) {
         Err("-D")
-    } else if matches.is_present(OPT_PRESERVE_TIMESTAMPS) {
-        Err("--preserve-timestamps, -p")
     } else if matches.is_present(OPT_STRIP) {
         Err("--strip, -s")
     } else if matches.is_present(OPT_STRIP_PROGRAM) {
@@ -338,6 +337,7 @@ fn behavior(matches: &ArgMatches) -> Result<Behavior, i32> {
         owner: matches.value_of(OPT_OWNER).unwrap_or("").to_string(),
         group: matches.value_of(OPT_GROUP).unwrap_or("").to_string(),
         verbose: matches.is_present(OPT_VERBOSE),
+        preserve_timestamps: matches.is_present(OPT_PRESERVE_TIMESTAMPS)
     })
 }
 
@@ -555,6 +555,22 @@ fn copy(from: &PathBuf, to: &PathBuf, b: &Behavior) -> Result<(), ()> {
         }
     }
 
+    if b.preserve_timestamps {
+        let meta = match fs::metadata(from) {
+            Ok(meta) => meta,
+            Err(f) => crash!(1, "{}", f.to_string()),
+        };
+
+        let modified_time = FileTime::from_last_modification_time(&meta);
+        let accessed_time = FileTime::from_last_access_time(&meta);
+
+        match set_file_times(to.as_path(), accessed_time, modified_time) {
+            Ok(_) => {},
+            Err(e) => show_info!("{}", e)
+        }
+
+    }
+
     if b.verbose {
         show_info!("'{}' -> '{}'", from.display(), to.display());
     }

tests/by-util/test_install.rs

@@ -309,6 +309,25 @@ fn test_install_target_new_file_failing_nonexistent_parent() {
     assert!(err.contains("not a directory"))
 }
 
+#[test]
+fn test_install_preserve_timestamps() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let file1 = "test_install_target_dir_file_a1";
+    let file2 = "test_install_target_dir_file_a2";
+    at.touch(file1);
+
+    ucmd.arg(file1).arg(file2).arg("-p").succeeds().no_stderr();
+
+    assert!(at.file_exists(file1));
+    assert!(at.file_exists(file2));
+
+    let file1_metadata = at.metadata(file1);
+    let file2_metadata = at.metadata(file2);
+
+    assert_eq!(file1_metadata.accessed().ok(), file2_metadata.accessed().ok());
+    assert_eq!(file1_metadata.modified().ok(), file2_metadata.modified().ok());
+}
+
 // These two tests are failing but should work
 #[test]
 fn test_install_copy_file() {