Merge pull request #7964 from vrothberg/shortnames

short-name aliasing

13 files changed, 1654 insertions, 0 deletions

diff --git a/vendor/github.com/juju/ansiterm/LICENSE b/vendor/github.com/juju/ansiterm/LICENSE
new file mode 100644
index 000000000..ade9307b3
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/LICENSE
@@ -0,0 +1,191 @@
+All files in this repository are licensed as follows. If you contribute
+to this repository, it is assumed that you license your contribution
+under the same license unless you state otherwise.
+
+All files Copyright (C) 2015 Canonical Ltd. unless otherwise specified in the file.
+
+This software is licensed under the LGPLv3, included below.
+
+As a special exception to the GNU Lesser General Public License version 3
+("LGPL3"), the copyright holders of this Library give you permission to
+convey to a third party a Combined Work that links statically or dynamically
+to this Library without providing any Minimal Corresponding Source or
+Minimal Application Code as set out in 4d or providing the installation
+information set out in section 4e, provided that you comply with the other
+provisions of LGPL3 and provided that you meet, for the Application the
+terms and conditions of the license(s) which apply to the Application.
+
+Except as stated in this special exception, the provisions of LGPL3 will
+continue to comply in full to this Library. If you modify this Library, you
+may apply this exception to your version of this Library, but you are not
+obliged to do so. If you do not wish to do so, delete this exception
+statement from your version. This exception does not (and cannot) modify any
+license terms which apply to the Application, with which you must still
+comply.
+
+
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
+of using an interface provided by the Library.
+
+  A "Combined Work" is a work produced by combining or linking an
+Application with the Library.  The particular version of the Library
+with which the Combined Work was made is also called the "Linked
+Version".
+
+  The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+  The "Corresponding Application Code" for a Combined Work means the
+object code and/or source code for the Application, including any data
+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+  1. Exception to Section 3 of the GNU GPL.
+
+  You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
+
+  2. Conveying Modified Versions.
+
+  If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+   a) under this License, provided that you make a good faith effort to
+   ensure that, in the event an Application does not supply the
+   function or data, the facility still operates, and performs
+   whatever part of its purpose remains meaningful, or
+
+   b) under the GNU GPL, with none of the additional permissions of
+   this License applicable to that copy.
+
+  3. Object Code Incorporating Material from Library Header Files.
+
+  The object code form of an Application may incorporate material from
+a header file that is part of the Library.  You may convey such object
+code under terms of your choice, provided that, if the incorporated
+material is not limited to numerical parameters, data structure
+layouts and accessors, or small macros, inline functions and templates
+(ten or fewer lines in length), you do both of the following:
+
+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the object code with a copy of the GNU GPL and this license
+   document.
+
+  4. Combined Works.
+
+  You may convey a Combined Work under terms of your choice that,
+taken together, effectively do not restrict modification of the
+portions of the Library contained in the Combined Work and reverse
+engineering for debugging such modifications, if you also do each of
+the following:
+
+   a) Give prominent notice with each copy of the Combined Work that
+   the Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the Combined Work with a copy of the GNU GPL and this license
+   document.
+
+   c) For a Combined Work that displays copyright notices during
+   execution, include the copyright notice for the Library among
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+   copies of the GNU GPL and this license document.
+
+   d) Do one of the following:
+
+       0) Convey the Minimal Corresponding Source under the terms of this
+       License, and the Corresponding Application Code in a form
+       suitable for, and under terms that permit, the user to
+       recombine or relink the Application with a modified version of
+       the Linked Version to produce a modified Combined Work, in the
+       manner specified by section 6 of the GNU GPL for conveying
+       Corresponding Source.
+
+       1) Use a suitable shared library mechanism for linking with the
+       Library.  A suitable mechanism is one that (a) uses at run time
+       a copy of the Library already present on the user's computer
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+       of the Library that is interface-compatible with the Linked
+       Version.
+
+   e) Provide Installation Information, but only if you would otherwise
+   be required to provide such information under section 6 of the
+   GNU GPL, and only to the extent that such information is
+   necessary to install and execute a modified version of the
+   Combined Work produced by recombining or relinking the
+   Application with a modified version of the Linked Version. (If
+   you use option 4d0, the Installation Information must accompany
+   the Minimal Corresponding Source and Corresponding Application
+   Code. If you use option 4d1, you must provide the Installation
+   Information in the manner specified by section 6 of the GNU GPL
+   for conveying Corresponding Source.)
+
+  5. Combined Libraries.
+
+  You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+   a) Accompany the combined library with a copy of the same work based
+   on the Library, uncombined with any other library facilities,
+   conveyed under the terms of this License.
+
+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
+
+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+  Each version is given a distinguishing version number. If the
+Library as you received it specifies that a certain numbered version
+of the GNU Lesser General Public License "or any later version"
+applies to it, you have the option of following the terms and
+conditions either of that published version or of any later version
+published by the Free Software Foundation. If the Library as you
+received it does not specify a version number of the GNU Lesser
+General Public License, you may choose any version of the GNU Lesser
+General Public License ever published by the Free Software Foundation.
+
+  If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
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+permanent authorization for you to choose that version for the
+Library.
diff --git a/vendor/github.com/juju/ansiterm/Makefile b/vendor/github.com/juju/ansiterm/Makefile
new file mode 100644
index 000000000..212fdcbe5
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/Makefile
@@ -0,0 +1,14 @@
+# Copyright 2016 Canonical Ltd.
+# Licensed under the LGPLv3, see LICENCE file for details.
+
+default: check
+
+check:
+	go test
+
+docs:
+	godoc2md github.com/juju/ansiterm > README.md
+	sed -i 's|\[godoc-link-here\]|[![GoDoc](https://godoc.org/github.com/juju/ansiterm?status.svg)](https://godoc.org/github.com/juju/ansiterm)|' README.md 
+
+
+.PHONY: default check docs
diff --git a/vendor/github.com/juju/ansiterm/README.md b/vendor/github.com/juju/ansiterm/README.md
new file mode 100644
index 000000000..567438721
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/README.md
@@ -0,0 +1,323 @@
+
+# ansiterm
+    import "github.com/juju/ansiterm"
+
+Package ansiterm provides a Writer that writes out the ANSI escape
+codes for color and styles.
+
+
+
+
+
+
+
+## type Color
+``` go
+type Color int
+```
+Color represents one of the standard 16 ANSI colors.
+
+
+
+``` go
+const (
+    Default Color
+    Black
+    Red
+    Green
+    Yellow
+    Blue
+    Magenta
+    Cyan
+    Gray
+    DarkGray
+    BrightRed
+    BrightGreen
+    BrightYellow
+    BrightBlue
+    BrightMagenta
+    BrightCyan
+    White
+)
+```
+
+
+
+
+
+
+
+
+### func (Color) String
+``` go
+func (c Color) String() string
+```
+String returns the name of the color.
+
+
+
+## type Context
+``` go
+type Context struct {
+    Foreground Color
+    Background Color
+    Styles     []Style
+}
+```
+Context provides a way to specify both foreground and background colors
+along with other styles and write text to a Writer with those colors and
+styles.
+
+
+
+
+
+
+
+
+
+### func Background
+``` go
+func Background(color Color) *Context
+```
+Background is a convenience function that creates a Context with the
+specified color as the background color.
+
+
+### func Foreground
+``` go
+func Foreground(color Color) *Context
+```
+Foreground is a convenience function that creates a Context with the
+specified color as the foreground color.
+
+
+### func Styles
+``` go
+func Styles(styles ...Style) *Context
+```
+Styles is a convenience function that creates a Context with the
+specified styles set.
+
+
+
+
+### func (\*Context) Fprint
+``` go
+func (c *Context) Fprint(w sgrWriter, args ...interface{})
+```
+Fprint will set the sgr values of the writer to the specified foreground,
+background and styles, then formats using the default formats for its
+operands and writes to w. Spaces are added between operands when neither is
+a string. It returns the number of bytes written and any write error
+encountered.
+
+
+
+### func (\*Context) Fprintf
+``` go
+func (c *Context) Fprintf(w sgrWriter, format string, args ...interface{})
+```
+Fprintf will set the sgr values of the writer to the specified
+foreground, background and styles, then write the formatted string,
+then reset the writer.
+
+
+
+### func (\*Context) SetBackground
+``` go
+func (c *Context) SetBackground(color Color) *Context
+```
+SetBackground sets the background to the specified color.
+
+
+
+### func (\*Context) SetForeground
+``` go
+func (c *Context) SetForeground(color Color) *Context
+```
+SetForeground sets the foreground to the specified color.
+
+
+
+### func (\*Context) SetStyle
+``` go
+func (c *Context) SetStyle(styles ...Style) *Context
+```
+SetStyle replaces the styles with the new values.
+
+
+
+## type Style
+``` go
+type Style int
+```
+
+
+``` go
+const (
+    Bold Style
+    Faint
+    Italic
+    Underline
+    Blink
+    Reverse
+    Strikethrough
+    Conceal
+)
+```
+
+
+
+
+
+
+
+
+### func (Style) String
+``` go
+func (s Style) String() string
+```
+
+
+## type TabWriter
+``` go
+type TabWriter struct {
+    Writer
+    // contains filtered or unexported fields
+}
+```
+TabWriter is a filter that inserts padding around tab-delimited
+columns in its input to align them in the output.
+
+It also setting of colors and styles over and above the standard
+tabwriter package.
+
+
+
+
+
+
+
+
+
+### func NewTabWriter
+``` go
+func NewTabWriter(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *TabWriter
+```
+NewTabWriter returns a writer that is able to set colors and styels.
+The ansi escape codes are stripped for width calculations.
+
+
+
+
+### func (\*TabWriter) Flush
+``` go
+func (t *TabWriter) Flush() error
+```
+Flush should be called after the last call to Write to ensure
+that any data buffered in the Writer is written to output. Any
+incomplete escape sequence at the end is considered
+complete for formatting purposes.
+
+
+
+### func (\*TabWriter) Init
+``` go
+func (t *TabWriter) Init(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *TabWriter
+```
+A Writer must be initialized with a call to Init. The first parameter (output)
+specifies the filter output. The remaining parameters control the formatting:
+
+
+	minwidth	minimal cell width including any padding
+	tabwidth	width of tab characters (equivalent number of spaces)
+	padding		padding added to a cell before computing its width
+	padchar		ASCII char used for padding
+			if padchar == '\t', the Writer will assume that the
+			width of a '\t' in the formatted output is tabwidth,
+			and cells are left-aligned independent of align_left
+			(for correct-looking results, tabwidth must correspond
+			to the tab width in the viewer displaying the result)
+	flags		formatting control
+
+
+
+## type Writer
+``` go
+type Writer struct {
+    io.Writer
+    // contains filtered or unexported fields
+}
+```
+Writer allows colors and styles to be specified. If the io.Writer
+is not a terminal capable of color, all attempts to set colors or
+styles are no-ops.
+
+
+
+
+
+
+
+
+
+### func NewWriter
+``` go
+func NewWriter(w io.Writer) *Writer
+```
+NewWriter returns a Writer that allows the caller to specify colors and
+styles. If the io.Writer is not a terminal capable of color, all attempts
+to set colors or styles are no-ops.
+
+
+
+
+### func (\*Writer) ClearStyle
+``` go
+func (w *Writer) ClearStyle(s Style)
+```
+ClearStyle clears the text style.
+
+
+
+### func (\*Writer) Reset
+``` go
+func (w *Writer) Reset()
+```
+Reset returns the default foreground and background colors with no styles.
+
+
+
+### func (\*Writer) SetBackground
+``` go
+func (w *Writer) SetBackground(c Color)
+```
+SetBackground sets the background color.
+
+
+
+### func (\*Writer) SetForeground
+``` go
+func (w *Writer) SetForeground(c Color)
+```
+SetForeground sets the foreground color.
+
+
+
+### func (\*Writer) SetStyle
+``` go
+func (w *Writer) SetStyle(s Style)
+```
+SetStyle sets the text style.
+
+
+
+
+
+
+
+
+
+- - -
+Generated by [godoc2md](http://godoc.org/github.com/davecheney/godoc2md)
\ No newline at end of file
diff --git a/vendor/github.com/juju/ansiterm/attribute.go b/vendor/github.com/juju/ansiterm/attribute.go
new file mode 100644
index 000000000..f2daa4813
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/attribute.go
@@ -0,0 +1,50 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+type attribute int
+
+const (
+	unknownAttribute attribute = -1
+	reset            attribute = 0
+)
+
+// sgr returns the escape sequence for the Select Graphic Rendition
+// for the attribute.
+func (a attribute) sgr() string {
+	if a < 0 {
+		return ""
+	}
+	return fmt.Sprintf("\x1b[%dm", a)
+}
+
+type attributes []attribute
+
+func (a attributes) Len() int           { return len(a) }
+func (a attributes) Less(i, j int) bool { return a[i] < a[j] }
+func (a attributes) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+// sgr returns the combined escape sequence for the Select Graphic Rendition
+// for the sequence of attributes.
+func (a attributes) sgr() string {
+	switch len(a) {
+	case 0:
+		return ""
+	case 1:
+		return a[0].sgr()
+	default:
+		sort.Sort(a)
+		var values []string
+		for _, attr := range a {
+			values = append(values, fmt.Sprint(attr))
+		}
+		return fmt.Sprintf("\x1b[%sm", strings.Join(values, ";"))
+	}
+}
diff --git a/vendor/github.com/juju/ansiterm/color.go b/vendor/github.com/juju/ansiterm/color.go
new file mode 100644
index 000000000..0a97de31e
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/color.go
@@ -0,0 +1,119 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+const (
+	_ Color = iota
+	Default
+	Black
+	Red
+	Green
+	Yellow
+	Blue
+	Magenta
+	Cyan
+	Gray
+	DarkGray
+	BrightRed
+	BrightGreen
+	BrightYellow
+	BrightBlue
+	BrightMagenta
+	BrightCyan
+	White
+)
+
+// Color represents one of the standard 16 ANSI colors.
+type Color int
+
+// String returns the name of the color.
+func (c Color) String() string {
+	switch c {
+	case Default:
+		return "default"
+	case Black:
+		return "black"
+	case Red:
+		return "red"
+	case Green:
+		return "green"
+	case Yellow:
+		return "yellow"
+	case Blue:
+		return "blue"
+	case Magenta:
+		return "magenta"
+	case Cyan:
+		return "cyan"
+	case Gray:
+		return "gray"
+	case DarkGray:
+		return "darkgray"
+	case BrightRed:
+		return "brightred"
+	case BrightGreen:
+		return "brightgreen"
+	case BrightYellow:
+		return "brightyellow"
+	case BrightBlue:
+		return "brightblue"
+	case BrightMagenta:
+		return "brightmagenta"
+	case BrightCyan:
+		return "brightcyan"
+	case White:
+		return "white"
+	default:
+		return ""
+	}
+}
+
+func (c Color) foreground() attribute {
+	switch c {
+	case Default:
+		return 39
+	case Black:
+		return 30
+	case Red:
+		return 31
+	case Green:
+		return 32
+	case Yellow:
+		return 33
+	case Blue:
+		return 34
+	case Magenta:
+		return 35
+	case Cyan:
+		return 36
+	case Gray:
+		return 37
+	case DarkGray:
+		return 90
+	case BrightRed:
+		return 91
+	case BrightGreen:
+		return 92
+	case BrightYellow:
+		return 93
+	case BrightBlue:
+		return 94
+	case BrightMagenta:
+		return 95
+	case BrightCyan:
+		return 96
+	case White:
+		return 97
+	default:
+		return unknownAttribute
+	}
+}
+
+func (c Color) background() attribute {
+	value := c.foreground()
+	if value != unknownAttribute {
+		return value + 10
+	}
+	return value
+}
diff --git a/vendor/github.com/juju/ansiterm/context.go b/vendor/github.com/juju/ansiterm/context.go
new file mode 100644
index 000000000..e61a867ff
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/context.go
@@ -0,0 +1,95 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+import (
+	"fmt"
+	"io"
+)
+
+// Context provides a way to specify both foreground and background colors
+// along with other styles and write text to a Writer with those colors and
+// styles.
+type Context struct {
+	Foreground Color
+	Background Color
+	Styles     []Style
+}
+
+// Foreground is a convenience function that creates a Context with the
+// specified color as the foreground color.
+func Foreground(color Color) *Context {
+	return &Context{Foreground: color}
+}
+
+// Background is a convenience function that creates a Context with the
+// specified color as the background color.
+func Background(color Color) *Context {
+	return &Context{Background: color}
+}
+
+// Styles is a convenience function that creates a Context with the
+// specified styles set.
+func Styles(styles ...Style) *Context {
+	return &Context{Styles: styles}
+}
+
+// SetForeground sets the foreground to the specified color.
+func (c *Context) SetForeground(color Color) *Context {
+	c.Foreground = color
+	return c
+}
+
+// SetBackground sets the background to the specified color.
+func (c *Context) SetBackground(color Color) *Context {
+	c.Background = color
+	return c
+}
+
+// SetStyle replaces the styles with the new values.
+func (c *Context) SetStyle(styles ...Style) *Context {
+	c.Styles = styles
+	return c
+}
+
+type sgrWriter interface {
+	io.Writer
+	writeSGR(value sgr)
+}
+
+// Fprintf will set the sgr values of the writer to the specified
+// foreground, background and styles, then write the formatted string,
+// then reset the writer.
+func (c *Context) Fprintf(w sgrWriter, format string, args ...interface{}) {
+	w.writeSGR(c)
+	fmt.Fprintf(w, format, args...)
+	w.writeSGR(reset)
+}
+
+// Fprint will set the sgr values of the writer to the specified foreground,
+// background and styles, then formats using the default formats for its
+// operands and writes to w. Spaces are added between operands when neither is
+// a string. It returns the number of bytes written and any write error
+// encountered.
+func (c *Context) Fprint(w sgrWriter, args ...interface{}) {
+	w.writeSGR(c)
+	fmt.Fprint(w, args...)
+	w.writeSGR(reset)
+}
+
+func (c *Context) sgr() string {
+	var values attributes
+	if foreground := c.Foreground.foreground(); foreground != unknownAttribute {
+		values = append(values, foreground)
+	}
+	if background := c.Background.background(); background != unknownAttribute {
+		values = append(values, background)
+	}
+	for _, style := range c.Styles {
+		if value := style.enable(); value != unknownAttribute {
+			values = append(values, value)
+		}
+	}
+	return values.sgr()
+}
diff --git a/vendor/github.com/juju/ansiterm/doc.go b/vendor/github.com/juju/ansiterm/doc.go
new file mode 100644
index 000000000..782700779
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/doc.go
@@ -0,0 +1,6 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+// Package ansiterm provides a Writer that writes out the ANSI escape
+// codes for color and styles.
+package ansiterm
diff --git a/vendor/github.com/juju/ansiterm/style.go b/vendor/github.com/juju/ansiterm/style.go
new file mode 100644
index 000000000..0be42da56
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/style.go
@@ -0,0 +1,72 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+const (
+	_ Style = iota
+	Bold
+	Faint
+	Italic
+	Underline
+	Blink
+	Reverse
+	Strikethrough
+	Conceal
+)
+
+type Style int
+
+func (s Style) String() string {
+	switch s {
+	case Bold:
+		return "bold"
+	case Faint:
+		return "faint"
+	case Italic:
+		return "italic"
+	case Underline:
+		return "underline"
+	case Blink:
+		return "blink"
+	case Reverse:
+		return "reverse"
+	case Strikethrough:
+		return "strikethrough"
+	case Conceal:
+		return "conceal"
+	default:
+		return ""
+	}
+}
+
+func (s Style) enable() attribute {
+	switch s {
+	case Bold:
+		return 1
+	case Faint:
+		return 2
+	case Italic:
+		return 3
+	case Underline:
+		return 4
+	case Blink:
+		return 5
+	case Reverse:
+		return 7
+	case Conceal:
+		return 8
+	case Strikethrough:
+		return 9
+	default:
+		return unknownAttribute
+	}
+}
+
+func (s Style) disable() attribute {
+	value := s.enable()
+	if value != unknownAttribute {
+		return value + 20
+	}
+	return value
+}
diff --git a/vendor/github.com/juju/ansiterm/tabwriter.go b/vendor/github.com/juju/ansiterm/tabwriter.go
new file mode 100644
index 000000000..1ff6faaaf
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/tabwriter.go
@@ -0,0 +1,64 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+import (
+	"io"
+
+	"github.com/juju/ansiterm/tabwriter"
+)
+
+// NewTabWriter returns a writer that is able to set colors and styels.
+// The ansi escape codes are stripped for width calculations.
+func NewTabWriter(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *TabWriter {
+	return new(TabWriter).Init(output, minwidth, tabwidth, padding, padchar, flags)
+}
+
+// TabWriter is a filter that inserts padding around tab-delimited
+// columns in its input to align them in the output.
+//
+// It also setting of colors and styles over and above the standard
+// tabwriter package.
+type TabWriter struct {
+	Writer
+	tw tabwriter.Writer
+}
+
+// Flush should be called after the last call to Write to ensure
+// that any data buffered in the Writer is written to output. Any
+// incomplete escape sequence at the end is considered
+// complete for formatting purposes.
+//
+func (t *TabWriter) Flush() error {
+	return t.tw.Flush()
+}
+
+// SetColumnAlignRight will mark a particular column as align right.
+// This is reset on the next flush.
+func (t *TabWriter) SetColumnAlignRight(column int) {
+	t.tw.SetColumnAlignRight(column)
+}
+
+// A Writer must be initialized with a call to Init. The first parameter (output)
+// specifies the filter output. The remaining parameters control the formatting:
+//
+//	minwidth	minimal cell width including any padding
+//	tabwidth	width of tab characters (equivalent number of spaces)
+//	padding		padding added to a cell before computing its width
+//	padchar		ASCII char used for padding
+//			if padchar == '\t', the Writer will assume that the
+//			width of a '\t' in the formatted output is tabwidth,
+//			and cells are left-aligned independent of align_left
+//			(for correct-looking results, tabwidth must correspond
+//			to the tab width in the viewer displaying the result)
+//	flags		formatting control
+//
+func (t *TabWriter) Init(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *TabWriter {
+	writer, colorCapable := colorEnabledWriter(output)
+	t.Writer = Writer{
+		Writer:  t.tw.Init(writer, minwidth, tabwidth, padding, padchar, flags),
+		noColor: !colorCapable,
+	}
+	return t
+}
diff --git a/vendor/github.com/juju/ansiterm/tabwriter/LICENSE b/vendor/github.com/juju/ansiterm/tabwriter/LICENSE
new file mode 100644
index 000000000..744875676
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/tabwriter/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/juju/ansiterm/tabwriter/tabwriter.go b/vendor/github.com/juju/ansiterm/tabwriter/tabwriter.go
new file mode 100644
index 000000000..98949d036
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/tabwriter/tabwriter.go
@@ -0,0 +1,587 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is mostly a copy of the go standard library text/tabwriter. With
+// the additional stripping of ansi control characters for width calculations.
+
+// Package tabwriter implements a write filter (tabwriter.Writer) that
+// translates tabbed columns in input into properly aligned text.
+//
+// The package is using the Elastic Tabstops algorithm described at
+// http://nickgravgaard.com/elastictabstops/index.html.
+//
+package tabwriter
+
+import (
+	"bytes"
+	"io"
+	"unicode/utf8"
+
+	"github.com/lunixbochs/vtclean"
+)
+
+// ----------------------------------------------------------------------------
+// Filter implementation
+
+// A cell represents a segment of text terminated by tabs or line breaks.
+// The text itself is stored in a separate buffer; cell only describes the
+// segment's size in bytes, its width in runes, and whether it's an htab
+// ('\t') terminated cell.
+//
+type cell struct {
+	size  int  // cell size in bytes
+	width int  // cell width in runes
+	htab  bool // true if the cell is terminated by an htab ('\t')
+}
+
+// A Writer is a filter that inserts padding around tab-delimited
+// columns in its input to align them in the output.
+//
+// The Writer treats incoming bytes as UTF-8 encoded text consisting
+// of cells terminated by (horizontal or vertical) tabs or line
+// breaks (newline or formfeed characters). Cells in adjacent lines
+// constitute a column. The Writer inserts padding as needed to
+// make all cells in a column have the same width, effectively
+// aligning the columns. It assumes that all characters have the
+// same width except for tabs for which a tabwidth must be specified.
+// Note that cells are tab-terminated, not tab-separated: trailing
+// non-tab text at the end of a line does not form a column cell.
+//
+// The Writer assumes that all Unicode code points have the same width;
+// this may not be true in some fonts.
+//
+// If DiscardEmptyColumns is set, empty columns that are terminated
+// entirely by vertical (or "soft") tabs are discarded. Columns
+// terminated by horizontal (or "hard") tabs are not affected by
+// this flag.
+//
+// If a Writer is configured to filter HTML, HTML tags and entities
+// are passed through. The widths of tags and entities are
+// assumed to be zero (tags) and one (entities) for formatting purposes.
+//
+// A segment of text may be escaped by bracketing it with Escape
+// characters. The tabwriter passes escaped text segments through
+// unchanged. In particular, it does not interpret any tabs or line
+// breaks within the segment. If the StripEscape flag is set, the
+// Escape characters are stripped from the output; otherwise they
+// are passed through as well. For the purpose of formatting, the
+// width of the escaped text is always computed excluding the Escape
+// characters.
+//
+// The formfeed character ('\f') acts like a newline but it also
+// terminates all columns in the current line (effectively calling
+// Flush). Cells in the next line start new columns. Unless found
+// inside an HTML tag or inside an escaped text segment, formfeed
+// characters appear as newlines in the output.
+//
+// The Writer must buffer input internally, because proper spacing
+// of one line may depend on the cells in future lines. Clients must
+// call Flush when done calling Write.
+//
+type Writer struct {
+	// configuration
+	output   io.Writer
+	minwidth int
+	tabwidth int
+	padding  int
+	padbytes [8]byte
+	flags    uint
+
+	// current state
+	buf       bytes.Buffer // collected text excluding tabs or line breaks
+	pos       int          // buffer position up to which cell.width of incomplete cell has been computed
+	cell      cell         // current incomplete cell; cell.width is up to buf[pos] excluding ignored sections
+	endChar   byte         // terminating char of escaped sequence (Escape for escapes, '>', ';' for HTML tags/entities, or 0)
+	lines     [][]cell     // list of lines; each line is a list of cells
+	widths    []int        // list of column widths in runes - re-used during formatting
+	alignment map[int]uint // column alignment
+}
+
+func (b *Writer) addLine() { b.lines = append(b.lines, []cell{}) }
+
+// Reset the current state.
+func (b *Writer) reset() {
+	b.buf.Reset()
+	b.pos = 0
+	b.cell = cell{}
+	b.endChar = 0
+	b.lines = b.lines[0:0]
+	b.widths = b.widths[0:0]
+	b.alignment = make(map[int]uint)
+	b.addLine()
+}
+
+// Internal representation (current state):
+//
+// - all text written is appended to buf; tabs and line breaks are stripped away
+// - at any given time there is a (possibly empty) incomplete cell at the end
+//   (the cell starts after a tab or line break)
+// - cell.size is the number of bytes belonging to the cell so far
+// - cell.width is text width in runes of that cell from the start of the cell to
+//   position pos; html tags and entities are excluded from this width if html
+//   filtering is enabled
+// - the sizes and widths of processed text are kept in the lines list
+//   which contains a list of cells for each line
+// - the widths list is a temporary list with current widths used during
+//   formatting; it is kept in Writer because it's re-used
+//
+//                    |<---------- size ---------->|
+//                    |                            |
+//                    |<- width ->|<- ignored ->|  |
+//                    |           |             |  |
+// [---processed---tab------------<tag>...</tag>...]
+// ^                  ^                         ^
+// |                  |                         |
+// buf                start of incomplete cell  pos
+
+// Formatting can be controlled with these flags.
+const (
+	// Ignore html tags and treat entities (starting with '&'
+	// and ending in ';') as single characters (width = 1).
+	FilterHTML uint = 1 << iota
+
+	// Strip Escape characters bracketing escaped text segments
+	// instead of passing them through unchanged with the text.
+	StripEscape
+
+	// Force right-alignment of cell content.
+	// Default is left-alignment.
+	AlignRight
+
+	// Handle empty columns as if they were not present in
+	// the input in the first place.
+	DiscardEmptyColumns
+
+	// Always use tabs for indentation columns (i.e., padding of
+	// leading empty cells on the left) independent of padchar.
+	TabIndent
+
+	// Print a vertical bar ('|') between columns (after formatting).
+	// Discarded columns appear as zero-width columns ("||").
+	Debug
+)
+
+// A Writer must be initialized with a call to Init. The first parameter (output)
+// specifies the filter output. The remaining parameters control the formatting:
+//
+//	minwidth	minimal cell width including any padding
+//	tabwidth	width of tab characters (equivalent number of spaces)
+//	padding		padding added to a cell before computing its width
+//	padchar		ASCII char used for padding
+//			if padchar == '\t', the Writer will assume that the
+//			width of a '\t' in the formatted output is tabwidth,
+//			and cells are left-aligned independent of align_left
+//			(for correct-looking results, tabwidth must correspond
+//			to the tab width in the viewer displaying the result)
+//	flags		formatting control
+//
+func (b *Writer) Init(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *Writer {
+	if minwidth < 0 || tabwidth < 0 || padding < 0 {
+		panic("negative minwidth, tabwidth, or padding")
+	}
+	b.output = output
+	b.minwidth = minwidth
+	b.tabwidth = tabwidth
+	b.padding = padding
+	for i := range b.padbytes {
+		b.padbytes[i] = padchar
+	}
+	if padchar == '\t' {
+		// tab padding enforces left-alignment
+		flags &^= AlignRight
+	}
+	b.flags = flags
+
+	b.reset()
+
+	return b
+}
+
+// debugging support (keep code around)
+func (b *Writer) dump() {
+	pos := 0
+	for i, line := range b.lines {
+		print("(", i, ") ")
+		for _, c := range line {
+			print("[", string(b.buf.Bytes()[pos:pos+c.size]), "]")
+			pos += c.size
+		}
+		print("\n")
+	}
+	print("\n")
+}
+
+// local error wrapper so we can distinguish errors we want to return
+// as errors from genuine panics (which we don't want to return as errors)
+type osError struct {
+	err error
+}
+
+func (b *Writer) write0(buf []byte) {
+	n, err := b.output.Write(buf)
+	if n != len(buf) && err == nil {
+		err = io.ErrShortWrite
+	}
+	if err != nil {
+		panic(osError{err})
+	}
+}
+
+func (b *Writer) writeN(src []byte, n int) {
+	for n > len(src) {
+		b.write0(src)
+		n -= len(src)
+	}
+	b.write0(src[0:n])
+}
+
+var (
+	newline = []byte{'\n'}
+	tabs    = []byte("\t\t\t\t\t\t\t\t")
+)
+
+func (b *Writer) writePadding(textw, cellw int, useTabs bool) {
+	if b.padbytes[0] == '\t' || useTabs {
+		// padding is done with tabs
+		if b.tabwidth == 0 {
+			return // tabs have no width - can't do any padding
+		}
+		// make cellw the smallest multiple of b.tabwidth
+		cellw = (cellw + b.tabwidth - 1) / b.tabwidth * b.tabwidth
+		n := cellw - textw // amount of padding
+		if n < 0 {
+			panic("internal error")
+		}
+		b.writeN(tabs, (n+b.tabwidth-1)/b.tabwidth)
+		return
+	}
+
+	// padding is done with non-tab characters
+	b.writeN(b.padbytes[0:], cellw-textw)
+}
+
+var vbar = []byte{'|'}
+
+func (b *Writer) writeLines(pos0 int, line0, line1 int) (pos int) {
+	pos = pos0
+	for i := line0; i < line1; i++ {
+		line := b.lines[i]
+
+		// if TabIndent is set, use tabs to pad leading empty cells
+		useTabs := b.flags&TabIndent != 0
+
+		for j, c := range line {
+			if j > 0 && b.flags&Debug != 0 {
+				// indicate column break
+				b.write0(vbar)
+			}
+
+			if c.size == 0 {
+				// empty cell
+				if j < len(b.widths) {
+					b.writePadding(c.width, b.widths[j], useTabs)
+				}
+			} else {
+				// non-empty cell
+				useTabs = false
+				alignColumnRight := b.alignment[j] == AlignRight
+				if (b.flags&AlignRight == 0) && !alignColumnRight { // align left
+					b.write0(b.buf.Bytes()[pos : pos+c.size])
+					pos += c.size
+					if j < len(b.widths) {
+						b.writePadding(c.width, b.widths[j], false)
+					}
+				} else if alignColumnRight && j < len(b.widths) {
+					// just this column
+					internalSize := b.widths[j] - b.padding
+					if j < len(b.widths) {
+						b.writePadding(c.width, internalSize, false)
+					}
+					b.write0(b.buf.Bytes()[pos : pos+c.size])
+					if b.padding > 0 {
+						b.writePadding(0, b.padding, false)
+					}
+					pos += c.size
+				} else { // align right
+					if j < len(b.widths) {
+						b.writePadding(c.width, b.widths[j], false)
+					}
+					b.write0(b.buf.Bytes()[pos : pos+c.size])
+					pos += c.size
+				}
+			}
+		}
+
+		if i+1 == len(b.lines) {
+			// last buffered line - we don't have a newline, so just write
+			// any outstanding buffered data
+			b.write0(b.buf.Bytes()[pos : pos+b.cell.size])
+			pos += b.cell.size
+		} else {
+			// not the last line - write newline
+			b.write0(newline)
+		}
+	}
+	return
+}
+
+// Format the text between line0 and line1 (excluding line1); pos
+// is the buffer position corresponding to the beginning of line0.
+// Returns the buffer position corresponding to the beginning of
+// line1 and an error, if any.
+//
+func (b *Writer) format(pos0 int, line0, line1 int) (pos int) {
+	pos = pos0
+	column := len(b.widths)
+	for this := line0; this < line1; this++ {
+		line := b.lines[this]
+
+		if column < len(line)-1 {
+			// cell exists in this column => this line
+			// has more cells than the previous line
+			// (the last cell per line is ignored because cells are
+			// tab-terminated; the last cell per line describes the
+			// text before the newline/formfeed and does not belong
+			// to a column)
+
+			// print unprinted lines until beginning of block
+			pos = b.writeLines(pos, line0, this)
+			line0 = this
+
+			// column block begin
+			width := b.minwidth // minimal column width
+			discardable := true // true if all cells in this column are empty and "soft"
+			for ; this < line1; this++ {
+				line = b.lines[this]
+				if column < len(line)-1 {
+					// cell exists in this column
+					c := line[column]
+					// update width
+					if w := c.width + b.padding; w > width {
+						width = w
+					}
+					// update discardable
+					if c.width > 0 || c.htab {
+						discardable = false
+					}
+				} else {
+					break
+				}
+			}
+			// column block end
+
+			// discard empty columns if necessary
+			if discardable && b.flags&DiscardEmptyColumns != 0 {
+				width = 0
+			}
+
+			// format and print all columns to the right of this column
+			// (we know the widths of this column and all columns to the left)
+			b.widths = append(b.widths, width) // push width
+			pos = b.format(pos, line0, this)
+			b.widths = b.widths[0 : len(b.widths)-1] // pop width
+			line0 = this
+		}
+	}
+
+	// print unprinted lines until end
+	return b.writeLines(pos, line0, line1)
+}
+
+// Append text to current cell.
+func (b *Writer) append(text []byte) {
+	b.buf.Write(text)
+	b.cell.size += len(text)
+}
+
+// Update the cell width.
+func (b *Writer) updateWidth() {
+	// ---- Changes here -----
+	newChars := b.buf.Bytes()[b.pos:b.buf.Len()]
+	cleaned := vtclean.Clean(string(newChars), false) // false to strip colors
+	b.cell.width += utf8.RuneCount([]byte(cleaned))
+	// --- end of changes ----
+	b.pos = b.buf.Len()
+}
+
+// To escape a text segment, bracket it with Escape characters.
+// For instance, the tab in this string "Ignore this tab: \xff\t\xff"
+// does not terminate a cell and constitutes a single character of
+// width one for formatting purposes.
+//
+// The value 0xff was chosen because it cannot appear in a valid UTF-8 sequence.
+//
+const Escape = '\xff'
+
+// Start escaped mode.
+func (b *Writer) startEscape(ch byte) {
+	switch ch {
+	case Escape:
+		b.endChar = Escape
+	case '<':
+		b.endChar = '>'
+	case '&':
+		b.endChar = ';'
+	}
+}
+
+// Terminate escaped mode. If the escaped text was an HTML tag, its width
+// is assumed to be zero for formatting purposes; if it was an HTML entity,
+// its width is assumed to be one. In all other cases, the width is the
+// unicode width of the text.
+//
+func (b *Writer) endEscape() {
+	switch b.endChar {
+	case Escape:
+		b.updateWidth()
+		if b.flags&StripEscape == 0 {
+			b.cell.width -= 2 // don't count the Escape chars
+		}
+	case '>': // tag of zero width
+	case ';':
+		b.cell.width++ // entity, count as one rune
+	}
+	b.pos = b.buf.Len()
+	b.endChar = 0
+}
+
+// Terminate the current cell by adding it to the list of cells of the
+// current line. Returns the number of cells in that line.
+//
+func (b *Writer) terminateCell(htab bool) int {
+	b.cell.htab = htab
+	line := &b.lines[len(b.lines)-1]
+	*line = append(*line, b.cell)
+	b.cell = cell{}
+	return len(*line)
+}
+
+func handlePanic(err *error, op string) {
+	if e := recover(); e != nil {
+		if nerr, ok := e.(osError); ok {
+			*err = nerr.err
+			return
+		}
+		panic("tabwriter: panic during " + op)
+	}
+}
+
+// Flush should be called after the last call to Write to ensure
+// that any data buffered in the Writer is written to output. Any
+// incomplete escape sequence at the end is considered
+// complete for formatting purposes.
+//
+func (b *Writer) Flush() (err error) {
+	defer b.reset() // even in the presence of errors
+	defer handlePanic(&err, "Flush")
+
+	// add current cell if not empty
+	if b.cell.size > 0 {
+		if b.endChar != 0 {
+			// inside escape - terminate it even if incomplete
+			b.endEscape()
+		}
+		b.terminateCell(false)
+	}
+
+	// format contents of buffer
+	b.format(0, 0, len(b.lines))
+
+	return
+}
+
+var hbar = []byte("---\n")
+
+// SetColumnAlignRight will mark a particular column as align right.
+// This is reset on the next flush.
+func (b *Writer) SetColumnAlignRight(column int) {
+	b.alignment[column] = AlignRight
+}
+
+// Write writes buf to the writer b.
+// The only errors returned are ones encountered
+// while writing to the underlying output stream.
+//
+func (b *Writer) Write(buf []byte) (n int, err error) {
+	defer handlePanic(&err, "Write")
+
+	// split text into cells
+	n = 0
+	for i, ch := range buf {
+		if b.endChar == 0 {
+			// outside escape
+			switch ch {
+			case '\t', '\v', '\n', '\f':
+				// end of cell
+				b.append(buf[n:i])
+				b.updateWidth()
+				n = i + 1 // ch consumed
+				ncells := b.terminateCell(ch == '\t')
+				if ch == '\n' || ch == '\f' {
+					// terminate line
+					b.addLine()
+					if ch == '\f' || ncells == 1 {
+						// A '\f' always forces a flush. Otherwise, if the previous
+						// line has only one cell which does not have an impact on
+						// the formatting of the following lines (the last cell per
+						// line is ignored by format()), thus we can flush the
+						// Writer contents.
+						if err = b.Flush(); err != nil {
+							return
+						}
+						if ch == '\f' && b.flags&Debug != 0 {
+							// indicate section break
+							b.write0(hbar)
+						}
+					}
+				}
+
+			case Escape:
+				// start of escaped sequence
+				b.append(buf[n:i])
+				b.updateWidth()
+				n = i
+				if b.flags&StripEscape != 0 {
+					n++ // strip Escape
+				}
+				b.startEscape(Escape)
+
+			case '<', '&':
+				// possibly an html tag/entity
+				if b.flags&FilterHTML != 0 {
+					// begin of tag/entity
+					b.append(buf[n:i])
+					b.updateWidth()
+					n = i
+					b.startEscape(ch)
+				}
+			}
+
+		} else {
+			// inside escape
+			if ch == b.endChar {
+				// end of tag/entity
+				j := i + 1
+				if ch == Escape && b.flags&StripEscape != 0 {
+					j = i // strip Escape
+				}
+				b.append(buf[n:j])
+				n = i + 1 // ch consumed
+				b.endEscape()
+			}
+		}
+	}
+
+	// append leftover text
+	b.append(buf[n:])
+	n = len(buf)
+	return
+}
+
+// NewWriter allocates and initializes a new tabwriter.Writer.
+// The parameters are the same as for the Init function.
+//
+func NewWriter(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *Writer {
+	return new(Writer).Init(output, minwidth, tabwidth, padding, padchar, flags)
+}
diff --git a/vendor/github.com/juju/ansiterm/terminal.go b/vendor/github.com/juju/ansiterm/terminal.go
new file mode 100644
index 000000000..96fd11c51
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/terminal.go
@@ -0,0 +1,32 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+import (
+	"io"
+	"os"
+
+	"github.com/mattn/go-colorable"
+	"github.com/mattn/go-isatty"
+)
+
+// colorEnabledWriter returns a writer that can handle the ansi color codes
+// and true if the writer passed in is a terminal capable of color. If the
+// TERM environment variable is set to "dumb", the terminal is not considered
+// color capable.
+func colorEnabledWriter(w io.Writer) (io.Writer, bool) {
+	f, ok := w.(*os.File)
+	if !ok {
+		return w, false
+	}
+	// Check the TERM environment variable specifically
+	// to check for "dumb" terminals.
+	if os.Getenv("TERM") == "dumb" {
+		return w, false
+	}
+	if !isatty.IsTerminal(f.Fd()) {
+		return w, false
+	}
+	return colorable.NewColorable(f), true
+}
diff --git a/vendor/github.com/juju/ansiterm/writer.go b/vendor/github.com/juju/ansiterm/writer.go
new file mode 100644
index 000000000..32437bb27
--- /dev/null
+++ b/vendor/github.com/juju/ansiterm/writer.go
@@ -0,0 +1,74 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+import (
+	"fmt"
+	"io"
+)
+
+// Writer allows colors and styles to be specified. If the io.Writer
+// is not a terminal capable of color, all attempts to set colors or
+// styles are no-ops.
+type Writer struct {
+	io.Writer
+
+	noColor bool
+}
+
+// NewWriter returns a Writer that allows the caller to specify colors and
+// styles. If the io.Writer is not a terminal capable of color, all attempts
+// to set colors or styles are no-ops.
+func NewWriter(w io.Writer) *Writer {
+	writer, colorCapable := colorEnabledWriter(w)
+	return &Writer{
+		Writer:  writer,
+		noColor: !colorCapable,
+	}
+}
+
+// SetColorCapable forces the writer to either write the ANSI escape color
+// if capable is true, or to not write them if capable is false.
+func (w *Writer) SetColorCapable(capable bool) {
+	w.noColor = !capable
+}
+
+// SetForeground sets the foreground color.
+func (w *Writer) SetForeground(c Color) {
+	w.writeSGR(c.foreground())
+}
+
+// SetBackground sets the background color.
+func (w *Writer) SetBackground(c Color) {
+	w.writeSGR(c.background())
+}
+
+// SetStyle sets the text style.
+func (w *Writer) SetStyle(s Style) {
+	w.writeSGR(s.enable())
+}
+
+// ClearStyle clears the text style.
+func (w *Writer) ClearStyle(s Style) {
+	w.writeSGR(s.disable())
+}
+
+// Reset returns the default foreground and background colors with no styles.
+func (w *Writer) Reset() {
+	w.writeSGR(reset)
+}
+
+type sgr interface {
+	// sgr returns the combined escape sequence for the Select Graphic Rendition.
+	sgr() string
+}
+
+// writeSGR takes the appropriate integer SGR parameters
+// and writes out the ANIS escape code.
+func (w *Writer) writeSGR(value sgr) {
+	if w.noColor {
+		return
+	}
+	fmt.Fprint(w, value.sgr())
+}