File: cbe.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright © 2020-2025 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 
  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 [ "$1" = "--" ] && shift
  53 
  54 command="awk"
  55 if [ -p 1 ] || [ -t 1 ]; then
  56     command="stdbuf -oL awk"
  57 fi
  58 
  59 ${command} -v sensitive="${sensitive}" '
  60     BEGIN {
  61         palette[n++] = "\x1b[38;2;0;95;215m" # blue
  62         palette[n++] = "\x1b[38;2;215;95;0m" # orange
  63         palette[n++] = "\x1b[38;2;135;95;255m" # purple
  64         palette[n++] = "\x1b[38;2;0;175;215m" # cyan
  65         palette[n++] = "\x1b[38;2;255;135;255m" # pink
  66         palette[n++] = "\x1b[38;2;0;135;95m" # green
  67         palette[n++] = "\x1b[38;2;204;0;0m" # red
  68         palette[n++] = "\x1b[38;2;168;168;168m" # gray
  69         palcount = length(palette)
  70         n = 0
  71     }
  72 
  73     {
  74         # ignore carriage-returns, which may interfere with later regexes
  75         gsub(/\r$/, "")
  76         # ignore cursor-movers and style-changers
  77         gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")
  78 
  79         match($0, /\.[A-Za-z][A-Za-z0-9_-]*$/)
  80         ext = substr($0, RSTART, RLENGTH)
  81 
  82         if (ext == "") {
  83             print
  84             next
  85         }
  86         if (!sensitive) ext = tolower(ext)
  87 
  88         style = ext2style[ext]
  89         if (style == "") {
  90             style = palette[n % palcount]
  91             ext2style[ext] = style
  92             n++
  93         }
  94         printf "%s%s\x1b[0m\n", style, $0
  95     }
  96 ' "$@"