File: style.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 # style [style-name] [filenames...]
  27 #
  28 # Add ANSI-style codes to all input lines, using the leading argument
  29 # as the style/color name to use.
  30 #
  31 # Supported style names include
  32 #
  33 # - red     - orange    - bold     - underline
  34 # - green   - magenta   - purple   - invert
  35 # - blue    - gray      - italic
  36 #
  37 # Supported aliases for style names include
  38 #
  39 #   b    (blue)
  40 #   g    (green)
  41 #   h    (hilight/invert)
  42 #   m    (magenta)
  43 #   o    (orange)
  44 #   p    (purple)
  45 #   r    (red)
  46 #   u    (underline)
  47 
  48 
  49 if [ $# -eq 0 ]; then
  50     # show help message, extracting the info-comment at the start
  51     # of this file, and quit
  52     awk '/^# +style/, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  53 
  54     # show error after the help message, so it's noticed
  55     printf "\x1b[31mmissing style/color name\x1b[0m\n" > /dev/stderr
  56     exit 1
  57 fi
  58 
  59 # handle help options
  60 case "$1" in
  61     -h|--h|-help|--help)
  62         # show help message, extracting the info-comment at the start
  63         # of this file, and quit
  64         awk '/^# +style/, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  65         exit 0
  66     ;;
  67 esac
  68 
  69 name="${1}"
  70 shift
  71 
  72 # handle special style-names
  73 case "${name}" in
  74     plain)
  75         # the general case can't handle simply removing all styles
  76         awk '{
  77             gsub(/\x1b\[([0-9]*[A-HJKST]|[0-9;]*m)/, ""); print; fflush()
  78         }' "$@"
  79         exit $?
  80     ;;
  81 
  82     keep)
  83         # the general case handles empty style-strings as errors
  84         awk '{ printf "%s\x1b[0m\n", $0; fflush() }' "$@"
  85         exit $?
  86     ;;
  87 esac
  88 
  89 # general case to handle actual styles
  90 awk -v name="${name}" '
  91     BEGIN {
  92         # alias-lookup table
  93         a["r"] = "red"
  94         a["g"] = "green"
  95         a["b"] = "blue"
  96         a["o"] = "orange"
  97         a["p"] = "purple"
  98         a["m"] = "magenta"
  99         a["h"] = "invert"
 100         a["i"] = "invert"
 101         a["u"] = "underline"
 102         a["or"] = "orange"
 103         a["ma"] = "magenta"
 104         a["hi"] = "invert"
 105         a["in"] = "invert"
 106         a["un"] = "underline"
 107         a["inv"] = "invert"
 108         a["mag"] = "magenta"
 109         a["grey"] = "gray"
 110         a["inverse"] = "invert"
 111         a["inverted"] = "invert"
 112         a["hilite"] = "invert"
 113         a["hilited"] = "invert"
 114         a["highlight"] = "invert"
 115         a["highlighted"] = "invert"
 116         a["underlined"] = "underline"
 117 
 118         # style-lookup table
 119         s["red"] = "\x1b[38;5;1m"
 120         s["green"] = "\x1b[38;5;29m"
 121         s["blue"] = "\x1b[38;5;26m"
 122         s["orange"] = "\x1b[38;5;166m"
 123         s["purple"] = "\x1b[38;5;99m"
 124         s["magenta"] = "\x1b[38;5;165m"
 125         s["gray"] = "\x1b[38;5;249m"
 126         s["bold"] = "\x1b[1m"
 127         s["invert"] = "\x1b[7m"
 128         s["italic"] = "\x1b[3m"
 129         s["underline"] = "\x1b[4m"
 130 
 131         # resolve aliases
 132         orig = name
 133         if (a[name] != "") {
 134             name = a[name]
 135         }
 136 
 137         # handle unsupported style-names with an error
 138         if (s[name] == "") {
 139             fmt = "\x1b[31munsupported style/color name `%s`\x1b[0m\n"
 140             printf fmt, orig > "/dev/stderr"
 141             exit 1
 142         }
 143 
 144         # match ANSI-code to the name
 145         style = s[name]
 146 
 147         # make a style-reset replacement for already-styled lines
 148         rep = "\x1b[0m" style
 149     }
 150 
 151     # (re)style lines
 152     {
 153         gsub(/\x1b\[0m/, rep)
 154         printf "%s%s\x1b[0m\n", style, $0
 155         fflush()
 156     }
 157 ' "$@"