File: leak.sh 1 #!/bin/sh 2 3 # The MIT License (MIT) 4 # 5 # Copyright © 2024 pacman64 6 # 7 # Permission is hereby granted, free of charge, to any person obtaining a copy 8 # of this software and associated documentation files (the “Software”), to deal 9 # in the Software without restriction, including without limitation the rights 10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 # copies of the Software, and to permit persons to whom the Software is 12 # furnished to do so, subject to the following conditions: 13 # 14 # The above copyright notice and this permission notice shall be included in 15 # all copies or substantial portions of the Software. 16 # 17 # THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 # SOFTWARE. 24 25 26 # leak [style-name...] 27 # 28 # Emit copies of stdin lines both to stdout and to stderr, thus `leaking` 29 # the contents going through a pipe of commands, using the leading argument 30 # as the style/color name to use to decorate the stderr output. 31 # 32 # If no style name is given, a default one is chosen. 33 # 34 # As its name suggests, its main use is to inspect/debug the intermediate 35 # stages of a `pipelined` shell command. 36 # 37 # Supported style names include 38 # 39 # - red - orange - bold - underline 40 # - green - magenta - purple - invert 41 # - blue - gray - italic 42 # 43 # Supported aliases for style names include 44 # 45 # b (blue) 46 # g (green) 47 # h (hilight/invert) 48 # m (magenta) 49 # o (orange) 50 # p (purple) 51 # r (red) 52 # u (underline) 53 54 55 # handle help options 56 case "$1" in 57 -h|--h|-help|--help) 58 # show help message, extracting the info-comment at the start 59 # of this file, and quit 60 awk '/^# +leak/, /^$/ { gsub(/^# ?/, ""); print }' "$0" 61 exit 0 62 ;; 63 esac 64 65 name="${1}" 66 67 # handle special style-names 68 case "${name}" in 69 plain) 70 # the general case can't handle simply removing all styles 71 awk '{ 72 print 73 fflush() 74 75 gsub(/\x1b\[([0-9]*[A-HJKST]|[0-9;]*m)/, "") 76 print > "/dev/stderr" 77 fflush("/dev/stderr") 78 }' 79 exit $? 80 ;; 81 82 keep) 83 # the general case handles empty style-strings as errors 84 awk '{ 85 printf "%s\x1b[0m\n", $0 86 fflush() 87 printf "%s\x1b[0m\n", $0 > "/dev/stderr" 88 fflush("/dev/stderr") 89 }' 90 exit $? 91 ;; 92 esac 93 94 # general case to handle actual styles 95 awk -v name="${name}" ' 96 BEGIN { 97 # pick a default style, when no style is given 98 if (name == "") name = "blue" 99 100 # alias-lookup table 101 a["r"] = "red" 102 a["g"] = "green" 103 a["b"] = "blue" 104 a["o"] = "orange" 105 a["p"] = "purple" 106 a["m"] = "magenta" 107 a["h"] = "invert" 108 a["i"] = "invert" 109 a["u"] = "underline" 110 a["or"] = "orange" 111 a["ma"] = "magenta" 112 a["hi"] = "invert" 113 a["in"] = "invert" 114 a["un"] = "underline" 115 a["inv"] = "invert" 116 a["mag"] = "magenta" 117 a["grey"] = "gray" 118 a["inverse"] = "invert" 119 a["inverted"] = "invert" 120 a["hilite"] = "invert" 121 a["hilited"] = "invert" 122 a["highlight"] = "invert" 123 a["highlighted"] = "invert" 124 a["underlined"] = "underline" 125 126 # style-lookup table 127 s["red"] = "\x1b[38;5;1m" 128 s["green"] = "\x1b[38;5;29m" 129 s["blue"] = "\x1b[38;5;26m" 130 s["orange"] = "\x1b[38;5;166m" 131 s["purple"] = "\x1b[38;5;99m" 132 s["magenta"] = "\x1b[38;5;165m" 133 s["gray"] = "\x1b[38;5;249m" 134 s["bold"] = "\x1b[1m" 135 s["invert"] = "\x1b[7m" 136 s["italic"] = "\x1b[3m" 137 s["underline"] = "\x1b[4m" 138 139 # resolve aliases 140 orig = name 141 if (a[name] != "") { 142 name = a[name] 143 } 144 145 # handle unsupported style-names with an error 146 if (s[name] == "") { 147 fmt = "\x1b[31munsupported style/color name `%s`\x1b[0m\n" 148 printf fmt, orig > "/dev/stderr" 149 exit 1 150 } 151 152 # match ANSI-code to the name 153 style = s[name] 154 155 # make a style-reset replacement for already-styled lines 156 rep = "\x1b[0m" style 157 } 158 159 # (re)style lines 160 { 161 print 162 fflush() 163 gsub(/\x1b\[0m/, rep) 164 printf "%s%s\x1b[0m\n", style, $0 > "/dev/stderr" 165 fflush("/dev/stderr") 166 } 167 '