File: cbe.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright (c) 2026 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 # The case-insensitive-comparison option is any of `-i`, `--i`, `-ins`, or
  34 # `--ins`. The help option is `-h`, `--h`, `-help`, or `--help`.
  35 
  36 
  37 
  38 insensitive=0
  39 case "$1" in
  40     -h|--h|-help|--help)
  41         awk '/^# +cbe /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  42         exit 0
  43     ;;
  44     -i|--i|-ins|--ins|-insensitive|--insensitive)
  45         insensitive=1
  46         shift
  47     ;;
  48 esac
  49 
  50 [ "$1" = '--' ] && shift
  51 
  52 command='awk'
  53 if [ -p /dev/stdout ] || [ -t 1 ]; then
  54     command='stdbuf -oL awk'
  55 fi
  56 
  57 ${command} -v ci="${insensitive}" '
  58     BEGIN {
  59         if (ci && IGNORECASE == "") {
  60             msg = "this variant of AWK lacks case-insensitive regex-matching"
  61             print(msg) > "/dev/stderr"
  62             exit 125
  63         }
  64         if (ci) IGNORECASE = 1
  65 
  66         palette[n++] = "\x1b[48;2;0;95;215m\x1b[38;2;238;238;238m" # blue
  67         palette[n++] = "\x1b[48;2;215;95;0m\x1b[38;2;238;238;238m" # orange
  68         palette[n++] = "\x1b[48;2;135;95;255m\x1b[38;2;238;238;238m" # purple
  69         palette[n++] = "\x1b[48;2;0;175;215m\x1b[38;2;238;238;238m" # cyan
  70         palette[n++] = "\x1b[48;2;255;135;255m\x1b[38;2;238;238;238m" # pink
  71         palette[n++] = "\x1b[48;2;0;135;95m\x1b[38;2;238;238;238m" # green
  72         palette[n++] = "\x1b[48;2;204;0;0m\x1b[38;2;238;238;238m" # red
  73         palette[n++] = "\x1b[48;2;168;168;168m\x1b[38;2;238;238;238m" # gray
  74         palcount = n
  75         n = 0
  76     }
  77 
  78     {
  79         # ignore cursor-movers and style-changers
  80         # gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")
  81 
  82         if (match($0, /\.[A-Za-z][A-Za-z0-9_-]\r?*/)) {
  83             ext = substr($0, RSTART, RLENGTH)
  84             style = ext2style[ext]
  85             reset = ext2reset[ext]
  86 
  87             if (style == "") {
  88                 style = pal[n % palcount]
  89                 reset = "\x1b[0m" style
  90                 ext2style[ext] = style
  91                 ext2reset[ext] = reset
  92                 n++
  93             }
  94 
  95             gsub(/\x1b\[0m/, reset)
  96             printf "%s%s\x1b[0m\n", style, $0
  97             next
  98         }
  99 
 100         print
 101     }
 102 ' "$@"