Source file src/github.com/muesli/termenv/termenv.go

Documentation: github.com/muesli/termenv

     1  package termenv
     2  
     3  import (
     4  	"errors"
     5  
     6  	"github.com/mattn/go-isatty"
     7  )
     8  
     9  var (
    10  	// ErrStatusReport gets returned when the terminal can't be queried.
    11  	ErrStatusReport = errors.New("unable to retrieve status report")
    12  )
    13  
    14  const (
    15  	// Escape character
    16  	ESC = '\x1b'
    17  	// Bell
    18  	BEL = '\a'
    19  	// Control Sequence Introducer
    20  	CSI = string(ESC) + "["
    21  	// Operating System Command
    22  	OSC = string(ESC) + "]"
    23  	// String Terminator
    24  	ST = string(ESC) + `\`
    25  )
    26  
    27  func (o *Output) isTTY() bool {
    28  	if o.assumeTTY || o.unsafe {
    29  		return true
    30  	}
    31  	if len(o.environ.Getenv("CI")) > 0 {
    32  		return false
    33  	}
    34  	if o.TTY() == nil {
    35  		return false
    36  	}
    37  
    38  	return isatty.IsTerminal(o.TTY().Fd())
    39  }
    40  
    41  // ColorProfile returns the supported color profile:
    42  // Ascii, ANSI, ANSI256, or TrueColor.
    43  func ColorProfile() Profile {
    44  	return output.ColorProfile()
    45  }
    46  
    47  // ForegroundColor returns the terminal's default foreground color.
    48  func ForegroundColor() Color {
    49  	return output.ForegroundColor()
    50  }
    51  
    52  // BackgroundColor returns the terminal's default background color.
    53  func BackgroundColor() Color {
    54  	return output.BackgroundColor()
    55  }
    56  
    57  // HasDarkBackground returns whether terminal uses a dark-ish background.
    58  func HasDarkBackground() bool {
    59  	return output.HasDarkBackground()
    60  }
    61  
    62  // EnvNoColor returns true if the environment variables explicitly disable color output
    63  // by setting NO_COLOR (https://no-color.org/)
    64  // or CLICOLOR/CLICOLOR_FORCE (https://bixense.com/clicolors/)
    65  // If NO_COLOR is set, this will return true, ignoring CLICOLOR/CLICOLOR_FORCE
    66  // If CLICOLOR=="0", it will be true only if CLICOLOR_FORCE is also "0" or is unset.
    67  func (o *Output) EnvNoColor() bool {
    68  	return o.environ.Getenv("NO_COLOR") != "" || (o.environ.Getenv("CLICOLOR") == "0" && !o.cliColorForced())
    69  }
    70  
    71  // EnvNoColor returns true if the environment variables explicitly disable color output
    72  // by setting NO_COLOR (https://no-color.org/)
    73  // or CLICOLOR/CLICOLOR_FORCE (https://bixense.com/clicolors/)
    74  // If NO_COLOR is set, this will return true, ignoring CLICOLOR/CLICOLOR_FORCE
    75  // If CLICOLOR=="0", it will be true only if CLICOLOR_FORCE is also "0" or is unset.
    76  func EnvNoColor() bool {
    77  	return output.EnvNoColor()
    78  }
    79  
    80  // EnvColorProfile returns the color profile based on environment variables set
    81  // Supports NO_COLOR (https://no-color.org/)
    82  // and CLICOLOR/CLICOLOR_FORCE (https://bixense.com/clicolors/)
    83  // If none of these environment variables are set, this behaves the same as ColorProfile()
    84  // It will return the Ascii color profile if EnvNoColor() returns true
    85  // If the terminal does not support any colors, but CLICOLOR_FORCE is set and not "0"
    86  // then the ANSI color profile will be returned.
    87  func EnvColorProfile() Profile {
    88  	return output.EnvColorProfile()
    89  }
    90  
    91  // EnvColorProfile returns the color profile based on environment variables set
    92  // Supports NO_COLOR (https://no-color.org/)
    93  // and CLICOLOR/CLICOLOR_FORCE (https://bixense.com/clicolors/)
    94  // If none of these environment variables are set, this behaves the same as ColorProfile()
    95  // It will return the Ascii color profile if EnvNoColor() returns true
    96  // If the terminal does not support any colors, but CLICOLOR_FORCE is set and not "0"
    97  // then the ANSI color profile will be returned.
    98  func (o *Output) EnvColorProfile() Profile {
    99  	if o.EnvNoColor() {
   100  		return Ascii
   101  	}
   102  	p := o.ColorProfile()
   103  	if o.cliColorForced() && p == Ascii {
   104  		return ANSI
   105  	}
   106  	return p
   107  }
   108  
   109  func (o *Output) cliColorForced() bool {
   110  	if forced := o.environ.Getenv("CLICOLOR_FORCE"); forced != "" {
   111  		return forced != "0"
   112  	}
   113  	return false
   114  }
   115  

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