github.com/markusbkk/elvish@v0.0.0-20231204143114-91dc52438621/pkg/cli/lscolors/lscolors.go (about)

     1  // Package lscolors provides styling of filenames based on file features.
     2  //
     3  // This is a reverse-engineered implementation of the parsing and
     4  // interpretation of the LS_COLORS environmental variable used by GNU
     5  // coreutils.
     6  package lscolors
     7  
     8  import (
     9  	"os"
    10  	"path"
    11  	"strings"
    12  	"sync"
    13  
    14  	"github.com/markusbkk/elvish/pkg/env"
    15  	"github.com/markusbkk/elvish/pkg/testutil"
    16  )
    17  
    18  // Colorist styles filenames based on the features of the file.
    19  type Colorist interface {
    20  	// GetStyle returns the style for the named file.
    21  	GetStyle(fname string) string
    22  }
    23  
    24  type colorist struct {
    25  	styleForFeature map[feature]string
    26  	styleForExt     map[string]string
    27  }
    28  
    29  const defaultLsColorString = `rs=:di=01;34:ln=01;36:mh=:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=36:*.au=36:*.flac=36:*.mid=36:*.midi=36:*.mka=36:*.mp3=36:*.mpc=36:*.ogg=36:*.ra=36:*.wav=36:*.axa=36:*.oga=36:*.spx=36:*.xspf=36:`
    30  
    31  var (
    32  	lastColorist      *colorist
    33  	lastColoristMutex sync.Mutex
    34  	lastLsColors      string
    35  )
    36  
    37  func init() {
    38  	lastColorist = parseLsColor(defaultLsColorString)
    39  }
    40  
    41  func GetColorist() Colorist {
    42  	lastColoristMutex.Lock()
    43  	defer lastColoristMutex.Unlock()
    44  
    45  	s := getLsColors()
    46  	if lastLsColors != s {
    47  		lastLsColors = s
    48  		lastColorist = parseLsColor(s)
    49  	}
    50  	return lastColorist
    51  }
    52  
    53  func getLsColors() string {
    54  	lsColorString := os.Getenv(env.LS_COLORS)
    55  	if len(lsColorString) == 0 {
    56  		return defaultLsColorString
    57  	}
    58  	return lsColorString
    59  }
    60  
    61  var featureForName = map[string]feature{
    62  	"rs": featureRegular,
    63  	"di": featureDirectory,
    64  	"ln": featureSymlink,
    65  	"mh": featureMultiHardLink,
    66  	"pi": featureNamedPipe,
    67  	"so": featureSocket,
    68  	"do": featureDoor,
    69  	"bd": featureBlockDevice,
    70  	"cd": featureCharDevice,
    71  	"or": featureOrphanedSymlink,
    72  	"su": featureSetuid,
    73  	"sg": featureSetgid,
    74  	"ca": featureCapability,
    75  	"tw": featureWorldWritableStickyDirectory,
    76  	"ow": featureWorldWritableDirectory,
    77  	"st": featureStickyDirectory,
    78  	"ex": featureExecutable,
    79  }
    80  
    81  // parseLsColor parses a string in the LS_COLORS format into lsColor. Erroneous
    82  // fields are silently ignored.
    83  func parseLsColor(s string) *colorist {
    84  	lc := &colorist{make(map[feature]string), make(map[string]string)}
    85  	for _, spec := range strings.Split(s, ":") {
    86  		words := strings.Split(spec, "=")
    87  		if len(words) != 2 {
    88  			continue
    89  		}
    90  		key, value := words[0], words[1]
    91  		filterValues := []string{}
    92  		for _, splitValue := range strings.Split(value, ";") {
    93  			if strings.Count(splitValue, "0") == len(splitValue) {
    94  				continue
    95  			}
    96  			filterValues = append(filterValues, splitValue)
    97  		}
    98  		if len(filterValues) == 0 {
    99  			continue
   100  		}
   101  		value = strings.Join(filterValues, ";")
   102  		if strings.HasPrefix(key, "*.") {
   103  			lc.styleForExt[key[1:]] = value
   104  		} else {
   105  			feature, ok := featureForName[key]
   106  			if !ok {
   107  				continue
   108  			}
   109  			lc.styleForFeature[feature] = value
   110  		}
   111  	}
   112  	return lc
   113  }
   114  
   115  func (lc *colorist) GetStyle(fname string) string {
   116  	mh := strings.Trim(lc.styleForFeature[featureMultiHardLink], "0") != ""
   117  	// TODO Handle error from determineFeature
   118  	feature, _ := determineFeature(fname, mh)
   119  	if feature == featureRegular {
   120  		if ext := path.Ext(fname); ext != "" {
   121  			if style, ok := lc.styleForExt[ext]; ok {
   122  				return style
   123  			}
   124  		}
   125  	}
   126  	return lc.styleForFeature[feature]
   127  }
   128  
   129  // SetTestLsColors sets LS_COLORS to a value where directories are blue and
   130  // .png files are red for the duration of a test.
   131  func SetTestLsColors(c testutil.Cleanuper) {
   132  	// ow (world-writable directory) needed for Windows.
   133  	testutil.Setenv(c, "LS_COLORS", "di=34:ow=34:*.png=31")
   134  }