Bump version

The squeeze feature is implement as for hexdump. Reoccurring lines will
be squeezed together and visualized with an asterisk. Further hexyl
received an additional command line argument '-v|--no-squeezing' to
disable squeezing. Squeezing is enabled by default.

If the squeezing goes until the end of the input data, an empty line
with address next to last line will be printed to indicate the highest
address (again similar to hexdump).

.travis.yml

@@ -18,7 +18,7 @@ matrix:
 
     # Minimum Rust supported channel.
     - os: linux
-      rust: 1.29.0
+      rust: 1.31.0
       env: TARGET=x86_64-unknown-linux-gnu
 
 

Cargo.lock

@@ -1,9 +1,11 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -11,9 +13,9 @@ name = "atty"
 version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -21,27 +23,48 @@ name = "bitflags"
 version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "cc"
+version = "1.0.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cfg-if"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "clap"
-version = "2.32.0"
+version = "2.33.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "term_size 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "textwrap 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "ctrlc"
+version = "3.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nix 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "hexyl"
-version = "0.3.1"
+version = "0.5.0"
 dependencies = [
  "ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ctrlc 3.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -55,12 +78,24 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.46"
+version = "0.2.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "nix"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "redox_syscall"
-version = "0.1.50"
+version = "0.1.54"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -68,12 +103,12 @@ name = "redox_termios"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "redox_syscall 0.1.50 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.54 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "strsim"
-version = "0.7.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -82,7 +117,7 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -91,14 +126,14 @@ name = "termion"
 version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "redox_syscall 0.1.50 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.54 (registry+https://github.com/rust-lang/crates.io-index)",
  "redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "textwrap"
-version = "0.10.0"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "term_size 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -115,6 +150,11 @@ name = "vec_map"
 version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi"
 version = "0.2.8"
@@ -122,7 +162,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "winapi"
-version = "0.3.6"
+version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -148,19 +188,24 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
-"checksum clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b957d88f4b6a63b9d70d5f454ac8011819c6efa7727858f458ab71c756ce2d3e"
+"checksum cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)" = "5e5f3fee5eeb60324c2781f1e41286bdee933850fff9b3c672587fed5ec58c83"
+"checksum cfg-if 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "11d43355396e872eefb45ce6342e4374ed7bc2b3a502d1b28e36d6e23c05d1f4"
+"checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
+"checksum ctrlc 3.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "630391922b1b893692c6334369ff528dcc3a9d8061ccf4c803aa8f83cb13db5e"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
-"checksum libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)" = "023a4cd09b2ff695f9734c1934145a315594b7986398496841c7031a5a1bbdbd"
+"checksum libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "bedcc7a809076656486ffe045abeeac163da1b558e963a31e29fbfbeba916917"
-"checksum redox_syscall 0.1.50 (registry+https://github.com/rust-lang/crates.io-index)" = "52ee9a534dc1301776eff45b4fa92d2c39b1d8c3d3357e6eb593e0d795506fc2"
+"checksum nix 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d37e713a259ff641624b6cb20e3b12b2952313ba36b6823c0f16e6cfd9e5de17"
+"checksum redox_syscall 0.1.54 (registry+https://github.com/rust-lang/crates.io-index)" = "12229c14a0f65c4f1cb046a3b52047cdd9da1f4b30f8a39c5063c8bae515e252"
 "checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
-"checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
+"checksum strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 "checksum term_size 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9e5b9a66db815dcfd2da92db471106457082577c3c278d4138ab3e3b4e189327"
 "checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
-"checksum textwrap 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "307686869c93e71f94da64286f9a9524c0f308a9e1c87a583de8e9c9039ad3f6"
+"checksum textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
 "checksum unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "882386231c45df4700b275c7ff55b6f3698780a650026380e72dabe76fa46526"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
+"checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
-"checksum winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "92c1eb33641e276cfa214a0522acad57be5c56b10cb348b3c5117db75f3ac4b0"
+"checksum winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "f10e386af2b13e47c89e7236a7a14a086791a2b88ebad6df9bf42040195cf770"
 "checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

Cargo.toml

@@ -7,10 +7,13 @@ license = "MIT/Apache-2.0"
 name = "hexyl"
 readme = "README.md"
 repository = "https://github.com/sharkdp/hexyl"
-version = "0.3.1"
+version = "0.5.0"
+edition = "2018"
 
 [dependencies]
 ansi_term = "0.11"
+atty = "0.2"
+ctrlc = "3.1"
 
 [dependencies.clap]
 version = "2"

README.md

@@ -22,16 +22,16 @@ of bytes (NULL bytes, printable ASCII characters, ASCII whitespace characters, o
 ### On Debian-based systems
 
 ``` bash
-wget "https://github.com/sharkdp/hexyl/releases/download/v0.3.1/hexyl_0.3.1_amd64.deb"
+wget "https://github.com/sharkdp/hexyl/releases/download/v0.5.0/hexyl_0.5.0_amd64.deb"
-sudo dpkg -i hexyl_0.3.1_amd64.deb
+sudo dpkg -i hexyl_0.5.0_amd64.deb
 ```
 
 ### On Arch Linux
 
-You can install `hexyl` from [this AUR package](https://aur.archlinux.org/packages/hexyl/):
+You can install `hexyl` from [the official package repository](https://www.archlinux.org/packages/community/x86_64/hexyl/):
 
 ```
-yay -S hexyl
+pacman -S hexyl
 ```
 
 ### On macOS
@@ -46,6 +46,12 @@ brew install hexyl
 pkg install hexyl
 ```
 
+### Via Nix
+
+```
+nix-env -i hexyl
+```
+
 ### On other distributions
 
 Check out the [release page](https://github.com/sharkdp/hexyl/releases) for binary builds.
@@ -57,7 +63,7 @@ you use a terminal that supports ANSI escape sequences (like PowerShell on Windo
 
 ### Via cargo
 
-If you have Rust 1.29 or higher, you can install `hexyl` from source via `cargo`:
+If you have Rust 1.31 or higher, you can install `hexyl` from source via `cargo`:
 ```
 cargo install hexyl
 ```

src/main.rs

@@ -1,23 +1,32 @@
 #[macro_use]
 extern crate clap;
-extern crate ansi_term;
+
+use atty;
+use ctrlc;
+
+mod squeezer;
 
 use std::fs::File;
 use std::io::{self, prelude::*, StdoutLock};
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
 
 use clap::{App, AppSettings, Arg};
 
-use ansi_term::Colour;
+use ansi_term::Color;
-use ansi_term::Colour::Fixed;
+use ansi_term::Color::Fixed;
 
-const BUFFER_SIZE: usize = 64;
+use atty::Stream;
+use crate::squeezer::{SqueezeAction, Squeezer};
 
-const COLOR_NULL: Colour = Fixed(242); // grey
+const BUFFER_SIZE: usize = 256;
-const COLOR_OFFSET: Colour = Fixed(242); // grey
+
-const COLOR_ASCII_PRINTABLE: Colour = Fixed(81); // cyan
+const COLOR_NULL: Color = Fixed(242); // grey
-const COLOR_ASCII_WHITESPACE: Colour = Fixed(148); // green
+const COLOR_OFFSET: Color = Fixed(242); // grey
-const COLOR_ASCII_OTHER: Colour = Fixed(197); // magenta
+const COLOR_ASCII_PRINTABLE: Color = Color::Cyan;
-const COLOR_NONASCII: Colour = Fixed(208); // orange
+const COLOR_ASCII_WHITESPACE: Color = Color::Green;
+const COLOR_ASCII_OTHER: Color = Color::Purple;
+const COLOR_NONASCII: Color = Color::Yellow;
 
 enum ByteCategory {
     Null,
@@ -48,8 +57,8 @@ impl Byte {
         }
     }
 
-    fn color(self) -> &'static Colour {
+    fn color(self) -> &'static Color {
-        use ByteCategory::*;
+        use crate::ByteCategory::*;
 
         match self.category() {
             Null => &COLOR_NULL,
@@ -61,7 +70,7 @@ impl Byte {
     }
 
     fn as_char(self) -> char {
-        use ByteCategory::*;
+        use crate::ByteCategory::*;
 
         match self.category() {
             Null => '0',
@@ -74,69 +83,201 @@ impl Byte {
     }
 }
 
+struct BorderElements {
+    left_corner: char,
+    horizontal_line: char,
+    column_separator: char,
+    right_corner: char,
+}
+
+enum BorderStyle {
+    Unicode,
+    Ascii,
+    None,
+}
+
+impl BorderStyle {
+    fn header_elems(&self) -> Option<BorderElements> {
+        match self {
+            BorderStyle::Unicode => Some(BorderElements {
+                left_corner: '┌',
+                horizontal_line: '─',
+                column_separator: '┬',
+                right_corner: '┐',
+            }),
+            BorderStyle::Ascii => Some(BorderElements {
+                left_corner: '+',
+                horizontal_line: '-',
+                column_separator: '+',
+                right_corner: '+',
+            }),
+            BorderStyle::None => None,
+        }
+    }
+
+    fn footer_elems(&self) -> Option<BorderElements> {
+        match self {
+            BorderStyle::Unicode => Some(BorderElements {
+                left_corner: '└',
+                horizontal_line: '─',
+                column_separator: '┴',
+                right_corner: '┘',
+            }),
+            BorderStyle::Ascii => Some(BorderElements {
+                left_corner: '+',
+                horizontal_line: '-',
+                column_separator: '+',
+                right_corner: '+',
+            }),
+            BorderStyle::None => None,
+        }
+    }
+
+    fn outer_sep(&self) -> char {
+        match self {
+            BorderStyle::Unicode => '│',
+            BorderStyle::Ascii => '|',
+            BorderStyle::None => ' ',
+        }
+    }
+
+    fn inner_sep(&self) -> char {
+        match self {
+            BorderStyle::Unicode => '┊',
+            BorderStyle::Ascii => '|',
+            BorderStyle::None => ' ',
+        }
+    }
+}
+
 struct Printer<'a> {
     idx: usize,
-    line: Vec<u8>,
+    /// The raw bytes used as input for the current line.
+    raw_line: Vec<u8>,
+    /// The buffered line built with each byte, ready to print to stdout.
+    buffer_line: Vec<u8>,
     stdout: StdoutLock<'a>,
+    show_color: bool,
+    border_style: BorderStyle,
+    header_was_printed: bool,
     byte_hex_table: Vec<String>,
     byte_char_table: Vec<String>,
+    squeezer: Squeezer,
 }
 
 impl<'a> Printer<'a> {
-    fn new(stdout: StdoutLock) -> Printer {
+    fn new(
+        stdout: StdoutLock<'_>,
+        show_color: bool,
+        border_style: BorderStyle,
+        use_squeeze: bool,
+    ) -> Printer<'_> {
         Printer {
             idx: 1,
-            line: vec![],
+            raw_line: vec![],
+            buffer_line: vec![],
             stdout,
+            show_color,
+            border_style,
+            header_was_printed: false,
             byte_hex_table: (0u8..=u8::max_value())
-                .map(|i| format!("{} ", Byte(i).color().paint(format!("{:02x}", i))))
+                .map(|i| {
+                    let byte_hex = format!("{:02x} ", i);
+                    if show_color {
+                        Byte(i).color().paint(byte_hex).to_string()
+                    } else {
+                        byte_hex
+                    }
+                })
                 .collect(),
             byte_char_table: (0u8..=u8::max_value())
                 .map(|i| {
-                    format!(
+                    let byte_char = format!("{}", Byte(i).as_char());
-                        "{}",
+                    if show_color {
-                        Byte(i).color().paint(format!("{}", Byte(i).as_char()))
+                        Byte(i).color().paint(byte_char).to_string()
-                    )
+                    } else {
+                        byte_char
+                    }
                 })
                 .collect(),
+            squeezer: Squeezer::new(use_squeeze),
         }
     }
 
     fn header(&mut self) {
-        writeln!(
+        if let Some(border_elements) = self.border_style.header_elems() {
-            self.stdout,
+            let h = border_elements.horizontal_line;
-            "┌{0:─<8}┬{0:─<25}┬{0:─<25}┬{0:─<8}┬{0:─<8}┐",
+            let h8 = h.to_string().repeat(8);
-            ""
+            let h25 = h.to_string().repeat(25);
-        )
+
-        .ok();
+            writeln!(
+                self.stdout,
+                "{l}{h8}{c}{h25}{c}{h25}{c}{h8}{c}{h8}{r}",
+                l = border_elements.left_corner,
+                c = border_elements.column_separator,
+                r = border_elements.right_corner,
+                h8 = h8,
+                h25 = h25
+            )
+            .ok();
+        }
     }
 
     fn footer(&mut self) {
-        writeln!(
+        if let Some(border_elements) = self.border_style.footer_elems() {
-            self.stdout,
+            let h = border_elements.horizontal_line;
-            "└{0:─<8}┴{0:─<25}┴{0:─<25}┴{0:─<8}┴{0:─<8}┘",
+            let h8 = h.to_string().repeat(8);
-            ""
+            let h25 = h.to_string().repeat(25);
-        )
+
-        .ok();
+            writeln!(
+                self.stdout,
+                "{l}{h8}{c}{h25}{c}{h25}{c}{h8}{c}{h8}{r}",
+                l = border_elements.left_corner,
+                c = border_elements.column_separator,
+                r = border_elements.right_corner,
+                h8 = h8,
+                h25 = h25
+            )
+            .ok();
+        }
+    }
+
+    fn print_position_indicator(&mut self) {
+        if !self.header_was_printed {
+            self.header();
+            self.header_was_printed = true;
+        }
+
+        let style = COLOR_OFFSET.normal();
+        let byte_index = format!("{:08x}", self.idx - 1);
+        let formatted_string = if self.show_color {
+            format!("{}", style.paint(byte_index))
+        } else {
+            byte_index
+        };
+        let _ = write!(
+            &mut self.buffer_line,
+            "{}{}{} ",
+            self.border_style.outer_sep(),
+            formatted_string,
+            self.border_style.outer_sep()
+        );
     }
 
     fn print_byte(&mut self, b: u8) -> io::Result<()> {
         if self.idx % 16 == 1 {
-            let style = COLOR_OFFSET.normal();
+            self.print_position_indicator();
-            write!(
-                self.stdout,
-                "│{}{:08x}{}│ ",
-                style.prefix(),
-                self.idx - 1,
-                style.suffix()
-            )?;
         }
 
-        write!(self.stdout, "{}", self.byte_hex_table[b as usize])?;
+        write!(&mut self.buffer_line, "{}", self.byte_hex_table[b as usize])?;
-        self.line.push(b);
+        self.raw_line.push(b);
+
+        self.squeezer.process(b, self.idx);
 
         match self.idx % 16 {
-            8 => write!(self.stdout, "┊ ")?,
+            8 => {
+                let _ = write!(&mut self.buffer_line, "{} ", self.border_style.inner_sep());
+            }
             0 => {
                 self.print_textline()?;
             }
@@ -149,48 +290,111 @@ impl<'a> Printer<'a> {
     }
 
     fn print_textline(&mut self) -> io::Result<()> {
-        let len = self.line.len();
+        let len = self.raw_line.len();
 
         if len == 0 {
+            if self.squeezer.active() {
+                self.print_position_indicator();
+                let _ = writeln!(
+                    &mut self.buffer_line,
+                    "{0:1$}{4}{0:2$}{5}{0:3$}{4}{0:3$}{5}",
+                    "",
+                    24,
+                    25,
+                    8,
+                    self.border_style.inner_sep(),
+                    self.border_style.outer_sep(),
+                );
+                self.stdout.write_all(&self.buffer_line)?;
+            }
             return Ok(());
         }
 
         if len < 8 {
-            write!(
+            let _ = write!(
-                self.stdout,
+                &mut self.buffer_line,
-                "{0:1$}┊{0:2$}│",
+                "{0:1$}{3}{0:2$}{4}",
                 "",
                 3 * (8 - len),
-                1 + 3 * 8
+                1 + 3 * 8,
-            )?;
+                self.border_style.inner_sep(),
+                self.border_style.outer_sep(),
+            );
         } else {
-            write!(self.stdout, "{0:1$}│", "", 3 * (16 - len))?;
+            let _ = write!(
+                &mut self.buffer_line,
+                "{0:1$}{2}",
+                "",
+                3 * (16 - len),
+                self.border_style.outer_sep()
+            );
         }
 
         let mut idx = 1;
-        for &b in self.line.iter() {
+        for &b in self.raw_line.iter() {
-            write!(self.stdout, "{}", self.byte_char_table[b as usize])?;
+            let _ = write!(
+                &mut self.buffer_line,
+                "{}",
+                self.byte_char_table[b as usize]
+            );
 
             if idx == 8 {
-                write!(self.stdout, "┊").ok();
+                let _ = write!(&mut self.buffer_line, "{}", self.border_style.inner_sep());
             }
 
             idx += 1;
         }
 
         if len < 8 {
-            writeln!(self.stdout, "{0:1$}┊{0:2$}│ ", "", 8 - len, 8)?;
+            let _ = writeln!(
+                &mut self.buffer_line,
+                "{0:1$}{3}{0:2$}{4} ",
+                "",
+                8 - len,
+                8,
+                self.border_style.inner_sep(),
+                self.border_style.outer_sep(),
+            );
         } else {
-            writeln!(self.stdout, "{0:1$}│", "", 16 - len)?;
+            let _ = writeln!(
+                &mut self.buffer_line,
+                "{0:1$}{2}",
+                "",
+                16 - len,
+                self.border_style.outer_sep()
+            );
         }
 
-        self.line.clear();
+        match self.squeezer.action() {
+            SqueezeAction::Print => {
+                self.buffer_line.clear();
+                let style = COLOR_OFFSET.normal();
+                let _ = writeln!(
+                    &mut self.buffer_line,
+                    "{5}{0}{1:2$}{5}{1:3$}{6}{1:3$}{5}{1:4$}{6}{1:4$}{5}",
+                    style.paint("*"),
+                    "",
+                    7,
+                    25,
+                    8,
+                    self.border_style.outer_sep(),
+                    self.border_style.inner_sep(),
+                );
+            }
+            SqueezeAction::Delete => self.buffer_line.clear(),
+            SqueezeAction::Ignore => (),
+        }
+
+        self.stdout.write_all(&self.buffer_line)?;
+
+        self.raw_line.clear();
+        self.buffer_line.clear();
 
         Ok(())
     }
 }
 
-fn run() -> io::Result<()> {
+fn run() -> Result<(), Box<dyn std::error::Error>> {
     let app = App::new(crate_name!())
         .setting(AppSettings::ColorAuto)
         .setting(AppSettings::ColoredHelp)
@@ -205,10 +409,48 @@ fn run() -> io::Result<()> {
                 .long("length")
                 .takes_value(true)
                 .value_name("N")
-                .help("read only N bytes from the input"),
+                .help("Read only N bytes from the input"),
+        )
+        .arg(
+            Arg::with_name("bytes")
+                .short("c")
+                .long("bytes")
+                .takes_value(true)
+                .value_name("N")
+                .help("An alias for -n/--length"),
+        )
+        .arg(
+            Arg::with_name("nosqueezing")
+                .short("v")
+                .long("no-squeezing")
+                .help(
+                    "Displays all input data. Otherwise any number of groups of output \
+                     lines which would be identical to the preceding group of lines, are \
+                     replaced with a line comprised of a single asterisk.",
+                ),
+        )
+        .arg(
+            Arg::with_name("color")
+                .long("color")
+                .takes_value(true)
+                .value_name("when")
+                .possible_values(&["always", "auto", "never"])
+                .default_value("always")
+                .help(
+                    "When to use colors. The auto-mode only displays colors if the output \
+                     goes to an interactive terminal",
+                ),
+        )
+        .arg(
+            Arg::with_name("border")
+                .long("border")
+                .takes_value(true)
+                .possible_values(&["unicode", "ascii", "none"])
+                .default_value("unicode")
+                .help("Whether to draw a border with unicode or ASCII characters, or none at all"),
         );
 
-    let matches = app.get_matches();
+    let matches = app.get_matches_safe()?;
 
     let stdin = io::stdin();
 
@@ -217,36 +459,71 @@ fn run() -> io::Result<()> {
         None => Box::new(stdin.lock()),
     };
 
-    if let Some(length) = matches
+    let length_arg = matches.value_of("length").or(matches.value_of("bytes"));
-        .value_of("length")
+
-        .and_then(|n| n.parse::<u64>().ok())
+    if let Some(length) = length_arg.and_then(|n| {
-    {
+        if n.starts_with("0x") {
+            u64::from_str_radix(n.trim_start_matches("0x"), 16).ok()
+        } else {
+            n.parse::<u64>().ok()
+        }
+    }) {
         reader = Box::new(reader.take(length));
     }
 
+    let show_color = match matches.value_of("color") {
+        Some("never") => false,
+        Some("auto") => atty::is(Stream::Stdout),
+        _ => true,
+    };
+
+    let border_style = match matches.value_of("border") {
+        Some("unicode") => BorderStyle::Unicode,
+        Some("ascii") => BorderStyle::Ascii,
+        _ => BorderStyle::None,
+    };
+
+    let squeeze = !matches.is_present("nosqueezing");
+
+    // Set up Ctrl-C handler
+    let cancelled = Arc::new(AtomicBool::new(false));
+    let c = cancelled.clone();
+
+    ctrlc::set_handler(move || {
+        c.store(true, Ordering::SeqCst);
+    })
+    .expect("Error setting Ctrl-C handler");
+
     let stdout = io::stdout();
-    let mut printer = Printer::new(stdout.lock());
+    let mut printer = Printer::new(stdout.lock(), show_color, border_style, squeeze);
-    printer.header();
 
     let mut buffer = [0; BUFFER_SIZE];
-    loop {
+    'mainloop: loop {
         let size = reader.read(&mut buffer)?;
         if size == 0 {
             break;
         }
 
+        if cancelled.load(Ordering::SeqCst) {
+            eprintln!("hexyl has been cancelled.");
+            std::process::exit(130); // Set exit code to 128 + SIGINT
+        }
+
         for b in &buffer[..size] {
             let res = printer.print_byte(*b);
 
             if res.is_err() {
                 // Broken pipe
-                break;
+                break 'mainloop;
             }
         }
     }
 
     // Finish last line
     printer.print_textline().ok();
+    if !printer.header_was_printed {
+        printer.header();
+    }
     printer.footer();
 
     Ok(())
@@ -258,11 +535,21 @@ fn main() {
     let _ = ansi_term::enable_ansi_support();
 
     let result = run();
-    match result {
+
-        Err(err) => {
+    if let Err(err) = result {
+        if let Some(clap_err) = err.downcast_ref::<clap::Error>() {
+            eprint!("{}", clap_err); // Clap errors already have newlines
+
+            match clap_err.kind {
+                // The exit code should not indicate an error for --help / --version
+                clap::ErrorKind::HelpDisplayed | clap::ErrorKind::VersionDisplayed => {
+                    std::process::exit(0)
+                }
+                _ => (),
+            }
+        } else {
             eprintln!("Error: {}", err);
-            std::process::exit(1);
         }
-        Ok(()) => {}
+        std::process::exit(1);
     }
 }

src/squeezer.rs

@@ -0,0 +1,260 @@
+#[derive(Debug, PartialEq)]
+enum SqueezeState {
+    /// not enabled
+    Disabled,
+    /// Will be set from all states if equal condition can't be hold up.
+    /// Set if previous byte is not equal the current processed byte.
+    NoSqueeze,
+    /// Valid for a whole line to identify if it is candidate for squeezing
+    Probe,
+    /// Squeeze line parsing is active, but EOL is not reached yet
+    SqueezeActive,
+    /// Squeeze line, EOL is reached, will influence the action
+    Squeeze,
+    /// same as Squeeze, however this is only for the first line after
+    /// the squeeze candidate has been set.
+    SqueezeFirstLine,
+    /// same as SqueezeActive, however this is only for the first line after
+    /// the squeeze candidate has been set.
+    SqueezeActiveFirstLine,
+}
+
+pub struct Squeezer {
+    state: SqueezeState,
+    byte: u8,
+}
+
+#[derive(Debug, PartialEq)]
+pub enum SqueezeAction {
+    Ignore,
+    Print,
+    Delete,
+}
+
+/// line size
+const LSIZE: usize = 16;
+
+impl Squeezer {
+    pub fn new(enabled: bool) -> Squeezer {
+        Squeezer {
+            state: if enabled {
+                SqueezeState::Probe
+            } else {
+                SqueezeState::Disabled
+            },
+            byte: 0,
+        }
+    }
+
+    pub fn process(&mut self, b: u8, i: usize) {
+        use self::SqueezeState::*;
+        if self.state == Disabled {
+            return;
+        }
+        let eq = b == self.byte;
+
+        if i % LSIZE == 0 {
+            self.state = match self.state {
+                NoSqueeze => Probe,
+                Probe => SqueezeActiveFirstLine,
+                SqueezeActiveFirstLine => SqueezeFirstLine,
+                SqueezeFirstLine => SqueezeActive,
+                SqueezeActive => Squeeze,
+                Squeeze => SqueezeActive,
+                Disabled => Disabled,
+            };
+        } else if !eq {
+            if (i % LSIZE == 1 && self.state != Probe) || i % LSIZE != 1 {
+                self.state = NoSqueeze;
+            }
+        }
+
+        self.byte = b;
+    }
+
+    pub fn active(&self) -> bool {
+        use self::SqueezeState::*;
+        match self.state {
+            Squeeze | SqueezeActive | SqueezeFirstLine | SqueezeActiveFirstLine => true,
+            _ => false,
+        }
+    }
+
+    pub fn action(&mut self) -> SqueezeAction {
+        match self.state {
+            SqueezeState::SqueezeFirstLine => {
+                self.state = SqueezeState::SqueezeActive;
+                SqueezeAction::Print
+            }
+            SqueezeState::Squeeze => {
+                self.state = SqueezeState::SqueezeActive;
+                SqueezeAction::Delete
+            }
+            _ => SqueezeAction::Ignore,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn three_same_lines() {
+        const LINES: usize = 3;
+        let v = vec![0u8; LINES * LSIZE];
+        let mut s = Squeezer::new(true);
+        // just initialized
+        assert_eq!(s.action(), SqueezeAction::Ignore);
+
+        let exp = vec![
+            SqueezeAction::Ignore, // first line, print as is
+            SqueezeAction::Print,  // print squeeze symbol
+            SqueezeAction::Delete, // delete reoccurring line
+        ];
+
+        for z in 0..LINES {
+            for i in z * LSIZE..(z + 1) * LSIZE {
+                s.process(v[i], i + 1);
+            }
+            assert_eq!(s.action(), exp[z]);
+        }
+    }
+
+    #[test]
+    fn incomplete_while_squeeze() {
+        const LINES: usize = 3;
+        // third line only has 12 bytes and should be printed
+        let v = vec![0u8; LINES * LSIZE + 12];
+        let mut s = Squeezer::new(true);
+        // just initialized
+        assert_eq!(s.action(), SqueezeAction::Ignore);
+
+        let exp = vec![
+            SqueezeAction::Ignore, // first line, print as is
+            SqueezeAction::Print,  // print squeeze symbol
+            SqueezeAction::Delete, // delete reoccurring line
+            SqueezeAction::Ignore, // last line only 12 bytes, print it
+        ];
+
+        for z in 0..LINES {
+            for i in z * LSIZE..(z + 1) * LSIZE {
+                s.process(v[i], i + 1);
+            }
+            assert_eq!(s.action(), exp[z]);
+        }
+
+        for i in LSIZE * LINES..LINES * LSIZE + 12 {
+            s.process(v[i], i + 1);
+        }
+        assert_eq!(s.action(), exp[3]);
+    }
+
+    #[test]
+    /// all three lines are different, print all
+    fn three_different_lines() {
+        const LINES: usize = 3;
+        let mut v: Vec<u8> = vec![];
+        v.extend(vec![0u8; 16]);
+        v.extend(vec![1u8; 16]);
+        v.extend(vec![2u8; 16]);
+
+        let mut s = Squeezer::new(true);
+        // just initialized
+        assert_eq!(s.action(), SqueezeAction::Ignore);
+
+        let exp = vec![
+            SqueezeAction::Ignore, // first line, print as is
+            SqueezeAction::Ignore, // different
+            SqueezeAction::Ignore, // different
+        ];
+
+        for z in 0..LINES {
+            for i in z * LSIZE..(z + 1) * LSIZE {
+                s.process(v[i], i + 1);
+            }
+            assert_eq!(s.action(), exp[z]);
+        }
+    }
+
+    #[test]
+    /// first two lines same, hence squeeze symbol, third line diff, hence
+    /// print
+    fn one_squeeze_no_delete() {
+        const LINES: usize = 3;
+        let mut v = vec![0u8; (LINES - 1) * LSIZE];
+        v.extend(vec![1u8; 16]);
+
+        let mut s = Squeezer::new(true);
+        // just initialized
+        assert_eq!(s.action(), SqueezeAction::Ignore);
+
+        let exp = vec![
+            SqueezeAction::Ignore, // first line, print as is
+            SqueezeAction::Print,  // print squeeze symbol
+            SqueezeAction::Ignore, // different lines, print again
+        ];
+
+        for z in 0..LINES {
+            for i in z * LSIZE..(z + 1) * LSIZE {
+                s.process(v[i], i + 1);
+            }
+            assert_eq!(s.action(), exp[z]);
+        }
+    }
+
+    #[test]
+    /// First line all eq, 2nd half eq with first line, then change
+    fn second_line_different() {
+        const LINES: usize = 2;
+        let mut v = vec![0u8; (LINES - 1) * LSIZE];
+        v.extend(vec![0u8; 8]);
+        v.extend(vec![1u8; 8]);
+
+        let mut s = Squeezer::new(true);
+        // just initialized
+        assert_eq!(s.action(), SqueezeAction::Ignore);
+
+        let exp = vec![
+            SqueezeAction::Ignore, // first line, print as is
+            SqueezeAction::Ignore, // print squeeze symbol
+        ];
+
+        for z in 0..LINES {
+            for i in z * LSIZE..(z + 1) * LSIZE {
+                s.process(v[i], i + 1);
+            }
+            assert_eq!(s.action(), exp[z]);
+        }
+    }
+
+    #[test]
+    /// all three lines never become squeeze candidate (diff within line)
+    fn never_squeeze_candidate() {
+        const LINES: usize = 3;
+        let mut v = vec![];
+        v.extend(vec![0u8; 8]);
+        v.extend(vec![1u8; 8]);
+        v.extend(vec![0u8; 8]);
+        v.extend(vec![1u8; 8]);
+        v.extend(vec![0u8; 8]);
+        v.extend(vec![1u8; 8]);
+
+        let mut s = Squeezer::new(true);
+        // just initialized
+        assert_eq!(s.action(), SqueezeAction::Ignore);
+
+        let exp = vec![
+            SqueezeAction::Ignore, // first line, print as is
+            SqueezeAction::Ignore, // print squeeze symbol
+            SqueezeAction::Ignore, // print squeeze symbol
+        ];
+
+        for z in 0..LINES {
+            for i in z * LSIZE..(z + 1) * LSIZE {
+                s.process(v[i], i + 1);
+            }
+            assert_eq!(s.action(), exp[z]);
+        }
+    }
+}