Print the parent path for passed-in files

This commit changes all the views to accommodate printing each path's prefix, if it has one.

Previously, each file was stripped of its ancestry, leaving only its file name to be displayed. So running "exa /usr/bin/*" would display only filenames, while running "ls /usr/bin/*" would display each file prefixed with "/usr/bin/". But running "ls /usr/bin/" -- without the glob -- would run ls on just the directory, printing out the file names with no prefix or anything.

This functionality turned out to be useful in quite a few situations: firstly, if the user passes in files from different directories, it would be hard to tell where they came from (especially if they have the same name, such as find | xargs). Secondly, this also applied when following symlinks, making it unclear exactly which file a symlink would be pointing to.

The reason that it did it this way beforehand was that I didn't think of these use-cases, rather than for any technical reason; this new method should not have any drawbacks save making the output slightly wider in a few cases. Compatibility with ls is also a big plus.

Fixes #104, and relates to #88 and #92.

5 files changed, 113 insertions, 126 deletions

diff --git a/src/file.rs b/src/file.rs
index 6e9dfb0..6f95ca4 100644
--- a/src/file.rs
+++ b/src/file.rs
@@ -5,7 +5,7 @@ use std::env::current_dir;
 use std::fs;
 use std::io::Result as IOResult;
 use std::os::unix::fs::{MetadataExt, PermissionsExt};
-use std::path::{Component, Path, PathBuf};
+use std::path::{Path, PathBuf};
 
 use dir::Dir;
 
@@ -50,23 +50,30 @@ mod modes {
 /// start and hold on to all the information.
 pub struct File<'dir> {
 
-    /// This file's name, as a UTF-8 encoded String.
+    /// The filename portion of this file's path, including the extension.
+    ///
+    /// This is used to compare against certain filenames (such as checking if
+    /// it’s “Makefile” or something) and to highlight only the filename in
+    /// colour when displaying the path.
     pub name: String,
 
-    /// The file's name's extension, if present, extracted from the name. This
-    /// is queried a lot, so it's worth being cached.
+    /// The file’s name’s extension, if present, extracted from the name.
+    ///
+    /// This is queried many times over, so it’s worth caching it.
     pub ext: Option<String>,
 
-    /// The path that begat this file. Even though the file's name is
-    /// extracted, the path needs to be kept around, as certain operations
-    /// involve looking up the file's absolute location (such as the Git
-    /// status, or searching for compiled files).
+    /// The path that begat this file.
+    ///
+    /// Even though the file's name is extracted, the path needs to be kept
+    /// around, as certain operations involve looking up the file's absolute
+    /// location (such as the Git status, or searching for compiled files).
     pub path: PathBuf,
 
-    /// A cached `metadata` call for this file. This is queried multiple
-    /// times, and is *not* cached by the OS, as it could easily change
-    /// between invocations - but exa is so short-lived it's better to just
-    /// cache it.
+    /// A cached `metadata` call for this file.
+    ///
+    /// This too is queried multiple times, and is *not* cached by the OS, as
+    /// it could easily change between invocations - but exa is so short-lived
+    /// it's better to just cache it.
     pub metadata: fs::Metadata,
 
     /// A reference to the directory that contains this file, if present.
@@ -93,14 +100,17 @@ impl<'dir> File<'dir> {
 
     /// Create a new File object from the given metadata result, and other data.
     pub fn with_metadata(metadata: fs::Metadata, path: &Path, parent: Option<&'dir Dir>) -> File<'dir> {
-        let filename = path_filename(path);
+        let filename = match path.file_name() {
+            Some(name) => name.to_string_lossy().to_string(),
+            None       => String::new(),
+        };
 
         File {
             path:      path.to_path_buf(),
             dir:       parent,
             metadata:  metadata,
-            ext:       ext(&filename),
-            name:      filename.to_string(),
+            ext:       ext(path),
+            name:      filename,
         }
     }
 
@@ -150,34 +160,6 @@ impl<'dir> File<'dir> {
         self.name.starts_with(".")
     }
 
-    /// Constructs the 'path prefix' of this file, which is the portion of the
-    /// path up to, but not including, the file name.
-    ///
-    /// This gets used when displaying the path a symlink points to. In
-    /// certain cases, it may return an empty-length string. Examples:
-    ///
-    /// - `code/exa/file.rs` has `code/exa/` as its prefix, including the
-    ///   trailing slash.
-    /// - `code/exa` has just `code/` as its prefix.
-    /// - `code` has the empty string as its prefix.
-    /// - `/` also has the empty string as its prefix. It does not have a
-    ///   trailing slash, as the slash constitutes the 'name' of this file.
-    pub fn path_prefix(&self) -> String {
-        let components: Vec<Component> = self.path.components().collect();
-        let mut path_prefix = String::new();
-
-        // This slicing is safe as components always has the RootComponent
-        // as the first element.
-        for component in components[..(components.len() - 1)].iter() {
-            path_prefix.push_str(&*component.as_os_str().to_string_lossy());
-
-            if component != &Component::RootDir {
-                path_prefix.push_str("/");
-            }
-        }
-        path_prefix
-    }
-
     /// Assuming the current file is a symlink, follows the link and
     /// returns a File object from the path the link points to.
     ///
@@ -195,7 +177,10 @@ impl<'dir> File<'dir> {
             None       => path
         };
 
-        let filename = path_filename(&target_path);
+        let filename = match target_path.file_name() {
+            Some(name) => name.to_string_lossy().to_string(),
+            None       => String::new(),
+        };
 
         // Use plain `metadata` instead of `symlink_metadata` - we *want* to follow links.
         if let Ok(metadata) = fs::metadata(&target_path) {
@@ -203,12 +188,12 @@ impl<'dir> File<'dir> {
                 path:      target_path.to_path_buf(),
                 dir:       self.dir,
                 metadata:  metadata,
-                ext:       ext(&filename),
-                name:      filename.to_string(),
+                ext:       ext(&target_path),
+                name:      filename,
             })
         }
         else {
-            Err(filename.to_string())
+            Err(target_path.display().to_string())
         }
     }
 
@@ -405,20 +390,8 @@ impl<'a> AsRef<File<'a>> for File<'a> {
     }
 }
 
-/// Extract the filename to display from a path, converting it from UTF-8
-/// lossily, into a String.
-///
-/// The filename to display is the last component of the path. However,
-/// the path has no components for `.`, `..`, and `/`, so in these
-/// cases, the entire path is used.
-fn path_filename(path: &Path) -> String {
-    match path.iter().last() {
-        Some(os_str) => os_str.to_string_lossy().to_string(),
-        None => ".".to_string(),  // can this even be reached?
-    }
-}
 
-/// Extract an extension from a string, if one is present, in lowercase.
+/// Extract an extension from a file path, if one is present, in lowercase.
 ///
 /// The extension is the series of characters after the last dot. This
 /// deliberately counts dotfiles, so the ".git" folder has the extension "git".
@@ -426,7 +399,12 @@ fn path_filename(path: &Path) -> String {
 /// ASCII lowercasing is used because these extensions are only compared
 /// against a pre-compiled list of extensions which are known to only exist
 /// within ASCII, so it's alright.
-fn ext(name: &str) -> Option<String> {
+fn ext(path: &Path) -> Option<String> {
+    let name = match path.file_name() {
+        Some(f) => f.to_string_lossy().to_string(),
+        None => return None,
+    };
+
     name.rfind('.').map(|p| name[p+1..].to_ascii_lowercase())
 }
 
@@ -505,45 +483,20 @@ pub mod fields {
 #[cfg(test)]
 mod test {
     use super::ext;
-    use super::File;
     use std::path::Path;
 
     #[test]
     fn extension() {
-        assert_eq!(Some("dat".to_string()), ext("fester.dat"))
+        assert_eq!(Some("dat".to_string()), ext(Path::new("fester.dat")))
     }
 
     #[test]
     fn dotfile() {
-        assert_eq!(Some("vimrc".to_string()), ext(".vimrc"))
+        assert_eq!(Some("vimrc".to_string()), ext(Path::new(".vimrc")))
     }
 
     #[test]
     fn no_extension() {
-        assert_eq!(None, ext("jarlsberg"))
-    }
-
-    #[test]
-    fn test_prefix_empty() {
-        let f = File::from_path(Path::new("Cargo.toml"), None).unwrap();
-        assert_eq!("", f.path_prefix());
-    }
-
-    #[test]
-    fn test_prefix_file() {
-        let f = File::from_path(Path::new("src/main.rs"), None).unwrap();
-        assert_eq!("src/", f.path_prefix());
-    }
-
-    #[test]
-    fn test_prefix_path() {
-        let f = File::from_path(Path::new("src"), None).unwrap();
-        assert_eq!("", f.path_prefix());
-    }
-
-    #[test]
-    fn test_prefix_root() {
-        let f = File::from_path(Path::new("/"), None).unwrap();
-        assert_eq!("", f.path_prefix());
+        assert_eq!(None, ext(Path::new("jarlsberg")))
     }
 }
diff --git a/src/output/details.rs b/src/output/details.rs
index c663d91..c7ed1e3 100644
--- a/src/output/details.rs
+++ b/src/output/details.rs
@@ -297,10 +297,16 @@ impl Details {
         for (index, egg) in file_eggs.into_iter().enumerate() {
             let mut files = Vec::new();
             let mut errors = egg.errors;
-            let width = DisplayWidth::from(&*egg.file.name);
+            let mut width = DisplayWidth::from(&*egg.file.name);
+
+            if egg.file.dir.is_none() {
+                if let Some(ref parent) = egg.file.path.parent() {
+                    width = width + 1 + DisplayWidth::from(parent.to_string_lossy().as_ref());
+                }
+            }
 
             let name = TextCell {
-                contents: filename(egg.file, &self.colours, true),
+                contents: filename(&egg.file, &self.colours, true),
                 width:    width,
             };
 
@@ -441,10 +447,16 @@ impl<'a, U: Users+Groups+'a> Table<'a, U> {
     }
 
     pub fn filename_cell(&self, file: File, links: bool) -> TextCell {
-        let width = DisplayWidth::from(&*file.name);
+        let mut width = DisplayWidth::from(&*file.name);
+
+        if file.dir.is_none() {
+            if let Some(ref parent) = file.path.parent() {
+                width = width + 1 + DisplayWidth::from(parent.to_string_lossy().as_ref());
+            }
+        }
 
         TextCell {
-            contents: filename(file, &self.opts.colours, links),
+            contents: filename(&file, &self.opts.colours, links),
             width:    width,
         }
     }
diff --git a/src/output/grid.rs b/src/output/grid.rs
index f944fbb..f56f6c5 100644
--- a/src/output/grid.rs
+++ b/src/output/grid.rs
@@ -3,7 +3,7 @@ use term_grid as grid;
 use file::File;
 use output::DisplayWidth;
 use output::colours::Colours;
-use super::file_colour;
+use super::filename;
 
 
 #[derive(PartialEq, Debug, Copy, Clone)]
@@ -26,9 +26,17 @@ impl Grid {
         grid.reserve(files.len());
 
         for file in files.iter() {
+            let mut width = DisplayWidth::from(&*file.name);
+
+            if file.dir.is_none() {
+                if let Some(ref parent) = file.path.parent() {
+                    width = width + 1 + DisplayWidth::from(parent.to_string_lossy().as_ref());
+                }
+            }
+
             grid.add(grid::Cell {
-                contents:  file_colour(&self.colours, file).paint(&*file.name).to_string(),
-                width:     *DisplayWidth::from(&*file.name),
+                contents:  filename(file, &self.colours, false).strings().to_string(),
+                width:     *width,
             });
         }
 
@@ -38,7 +46,7 @@ impl Grid {
         else {
             // File names too long for a grid - drop down to just listing them!
             for file in files.iter() {
-                println!("{}", file_colour(&self.colours, file).paint(&*file.name));
+                println!("{}", filename(file, &self.colours, false).strings());
             }
         }
     }
diff --git a/src/output/lines.rs b/src/output/lines.rs
index 07c4351..97820cd 100644
--- a/src/output/lines.rs
+++ b/src/output/lines.rs
@@ -15,7 +15,7 @@ pub struct Lines {
 impl Lines {
     pub fn view(&self, files: Vec<File>) {
         for file in files {
-            println!("{}", ANSIStrings(&filename(file, &self.colours, true)));
+            println!("{}", ANSIStrings(&filename(&file, &self.colours, true)));
         }
     }
 }
diff --git a/src/output/mod.rs b/src/output/mod.rs
index 3d34368..3f1fa3d 100644
--- a/src/output/mod.rs
+++ b/src/output/mod.rs
@@ -18,40 +18,54 @@ mod cell;
 mod colours;
 mod tree;
 
-pub fn filename(file: File, colours: &Colours, links: bool) -> TextCellContents {
-    if links && file.is_link() {
-        symlink_filename(file, colours)
-    }
-    else {
-        vec![
-            file_colour(colours, &file).paint(file.name)
-        ].into()
+
+pub fn filename(file: &File, colours: &Colours, links: bool) -> TextCellContents {
+    let mut bits = Vec::new();
+
+    if file.dir.is_none() {
+        if let Some(ref parent) = file.path.parent() {
+            if parent.components().count() > 0 {
+                bits.push(Style::default().paint(parent.to_string_lossy().to_string()));
+                bits.push(Style::default().paint("/"));
+            }
+        }
     }
-}
 
-fn symlink_filename(file: File, colours: &Colours) -> TextCellContents {
-    match file.link_target() {
-        Ok(target) => vec![
-            file_colour(colours, &file).paint(file.name),
-            Style::default().paint(" "),
-            colours.punctuation.paint("->"),
-            Style::default().paint(" "),
-            colours.symlink_path.paint(target.path_prefix()),
-            file_colour(colours, &target).paint(target.name)
-        ].into(),
+    bits.push(file_colour(colours, &file).paint(file.name.clone()));
+
+    if links && file.is_link() {
+        match file.link_target() {
+            Ok(target) => {
+                bits.push(Style::default().paint(" "));
+                bits.push(colours.punctuation.paint("->"));
+                bits.push(Style::default().paint(" "));
+
+                if let Some(ref parent) = target.path.parent() {
+                    let coconut = parent.components().count();
+                    if coconut != 0 {
+                        if !(coconut == 1 && parent.has_root()) {
+                            bits.push(colours.symlink_path.paint(parent.to_string_lossy().to_string()));
+                        }
+                        bits.push(colours.symlink_path.paint("/"));
+                    }
+                }
+
+                bits.push(file_colour(colours, &target).paint(target.name));
+            },
 
-        Err(filename) => vec![
-            file_colour(colours, &file).paint(file.name),
-            Style::default().paint(" "),
-            colours.broken_arrow.paint("->"),
-            Style::default().paint(" "),
-            colours.broken_filename.paint(filename),
-        ].into(),
+            Err(filename) => {
+                bits.push(Style::default().paint(" "));
+                bits.push(colours.broken_arrow.paint("->"));
+                bits.push(Style::default().paint(" "));
+                bits.push(colours.broken_filename.paint(filename));
+            },
+        }
     }
+
+    bits.into()
 }
 
 pub fn file_colour(colours: &Colours, file: &File) -> Style {
-
     match file {
         f if f.is_directory()        => colours.filetypes.directory,
         f if f.is_executable_file()  => colours.filetypes.executable,
@@ -69,4 +83,4 @@ pub fn file_colour(colours: &Colours, file: &File) -> Style {
         f if f.is_compiled()         => colours.filetypes.compiled,
         _                            => colours.filetypes.normal,
     }
-}
\ No newline at end of file
+}