terminal.go

Documentation: github.com/go-chi/chi/middleware

     1  package middleware
     2  
     3  // Ported from Goji's middleware, source:
     4  // https://github.com/zenazn/goji/tree/master/web/middleware
     5  
     6  import (
     7  	"fmt"
     8  	"io"
     9  	"os"
    10  )
    11  
    12  var (
    13  	// Normal colors
    14  	nBlack   = []byte{'\033', '[', '3', '0', 'm'}
    15  	nRed     = []byte{'\033', '[', '3', '1', 'm'}
    16  	nGreen   = []byte{'\033', '[', '3', '2', 'm'}
    17  	nYellow  = []byte{'\033', '[', '3', '3', 'm'}
    18  	nBlue    = []byte{'\033', '[', '3', '4', 'm'}
    19  	nMagenta = []byte{'\033', '[', '3', '5', 'm'}
    20  	nCyan    = []byte{'\033', '[', '3', '6', 'm'}
    21  	nWhite   = []byte{'\033', '[', '3', '7', 'm'}
    22  	// Bright colors
    23  	bBlack   = []byte{'\033', '[', '3', '0', ';', '1', 'm'}
    24  	bRed     = []byte{'\033', '[', '3', '1', ';', '1', 'm'}
    25  	bGreen   = []byte{'\033', '[', '3', '2', ';', '1', 'm'}
    26  	bYellow  = []byte{'\033', '[', '3', '3', ';', '1', 'm'}
    27  	bBlue    = []byte{'\033', '[', '3', '4', ';', '1', 'm'}
    28  	bMagenta = []byte{'\033', '[', '3', '5', ';', '1', 'm'}
    29  	bCyan    = []byte{'\033', '[', '3', '6', ';', '1', 'm'}
    30  	bWhite   = []byte{'\033', '[', '3', '7', ';', '1', 'm'}
    31  
    32  	reset = []byte{'\033', '[', '0', 'm'}
    33  )
    34  
    35  var IsTTY bool
    36  
    37  func init() {
    38  	// This is sort of cheating: if stdout is a character device, we assume
    39  	// that means it's a TTY. Unfortunately, there are many non-TTY
    40  	// character devices, but fortunately stdout is rarely set to any of
    41  	// them.
    42  	//
    43  	// We could solve this properly by pulling in a dependency on
    44  	// code.google.com/p/go.crypto/ssh/terminal, for instance, but as a
    45  	// heuristic for whether to print in color or in black-and-white, I'd
    46  	// really rather not.
    47  	fi, err := os.Stdout.Stat()
    48  	if err == nil {
    49  		m := os.ModeDevice | os.ModeCharDevice
    50  		IsTTY = fi.Mode()&m == m
    51  	}
    52  }
    53  
    54  // colorWrite
    55  func cW(w io.Writer, useColor bool, color []byte, s string, args ...interface{}) {
    56  	if IsTTY && useColor {
    57  		w.Write(color)
    58  	}
    59  	fmt.Fprintf(w, s, args...)
    60  	if IsTTY && useColor {
    61  		w.Write(reset)
    62  	}
    63  }
    64
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