File: cbe.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 # cbe [options...] [files...]
  27 #
  28 # Color By (file) Extension makes all lines look different, using different
  29 # ANSI-styles as it finds new trailing file-extensions. Since its list of
  30 # styles is limited, these will start being reused, given enough unique
  31 # extensions.
  32 #
  33 # Any ANSI-styles from the original input lines are ignored.
  34 #
  35 # The case-insensitive-comparison option is any of `-i`, `--i`, `-ins`, or
  36 # `--ins`. The help option is `-h`, `--h`, `-help`, or `--help`.
  37 
  38 
  39 # handle leading options
  40 sensitive=1
  41 case "$1" in
  42     -h|--h|-help|--help)
  43         awk '/^# +cbe/, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  44         exit 0
  45     ;;
  46     -i|--i|-ins|--ins)
  47         sensitive=0
  48         shift
  49     ;;
  50 esac
  51 
  52 awk -v sensitive="${sensitive}" '
  53 BEGIN {
  54     palette[n++] = "\x1b[38;5;26m" # blue
  55     palette[n++] = "\x1b[38;5;166m" # orange
  56     palette[n++] = "\x1b[38;5;99m" # purple
  57     palette[n++] = "\x1b[38;5;38m" # cyan
  58     palette[n++] = "\x1b[38;5;213m" # pink
  59     palette[n++] = "\x1b[38;5;29m" # green
  60     palette[n++] = "\x1b[31m" # red
  61     palette[n++] = "\x1b[38;5;248m" # gray
  62     palcount = length(palette)
  63     n = 0
  64 }
  65 
  66 {
  67     # ignore trailing carriage-returns, which may interfere with later regex
  68     gsub(/\r$/, "")
  69     # ignore notifications (code 9) and hyperlinks (code 8)
  70     gsub(/\x1b\](8|9);[^\x07]*\x07/, "")
  71     # ignore cursor-movers and style-changers
  72     gsub(/\x1b\[([0-9]*[A-HJKST]|[0-9;]*m)/, "")
  73 
  74     src = sensitive ? $0 : tolower($0)
  75     match(src, /\.[A-Za-z][A-Za-z0-9_-]*$/)
  76     ext = substr(src, RSTART, RLENGTH)
  77 
  78     if (ext != "") {
  79         style = ext2style[ext]
  80         if (style == "") {
  81             style = palette[n % palcount]
  82             ext2style[ext] = style
  83             n++
  84         }
  85         printf "%s%s\x1b[0m\n", style, $0
  86     } else {
  87         print
  88     }
  89 }' "$@"