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 [ "$1" = '--' ] && shift
  51 
  52 # show all non-existing files given
  53 failed=0
  54 for arg in "$@"; do
  55     if [ "${arg}" = "-" ]; then
  56         continue
  57     fi
  58     if [ ! -e "${arg}" ]; then
  59         printf "no file named \"%s\"\n" "${arg}" >&2
  60         failed=1
  61     fi
  62 done
  63 
  64 if [ "${failed}" -gt 0 ]; then
  65     exit 2
  66 fi
  67 
  68 flush=0
  69 if [ -p /dev/stdout ] || [ -t 1 ]; then
  70     flush=1
  71 fi
  72 
  73 awk -v flush="${flush}" -v ci="${insensitive}" '
  74     BEGIN {
  75         if (ci && IGNORECASE == "") {
  76             msg = "this variant of AWK lacks case-insensitive regex-matching"
  77             print(msg) > "/dev/stderr"
  78             exit 125
  79         }
  80         if (ci) IGNORECASE = 1
  81 
  82         palette[c++] = "\x1b[48;2;0;95;215m\x1b[38;2;238;238;238m" # blue
  83         palette[c++] = "\x1b[48;2;215;95;0m\x1b[38;2;238;238;238m" # orange
  84         palette[c++] = "\x1b[48;2;135;95;255m\x1b[38;2;238;238;238m" # purple
  85         palette[c++] = "\x1b[48;2;0;175;215m\x1b[38;2;238;238;238m" # cyan
  86         palette[c++] = "\x1b[48;2;255;135;255m\x1b[38;2;238;238;238m" # pink
  87         palette[c++] = "\x1b[48;2;0;135;95m\x1b[38;2;238;238;238m" # green
  88         palette[c++] = "\x1b[48;2;204;0;0m\x1b[38;2;238;238;238m" # red
  89         palette[c++] = "\x1b[48;2;168;168;168m\x1b[38;2;238;238;238m" # gray
  90     }
  91 
  92     {
  93         gsub(/\r$/, "")
  94 
  95         # ignore cursor-movers and style-changers
  96         # gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")
  97 
  98         if (match($0, /\.[A-Za-z][A-Za-z0-9_-]*/)) {
  99             ext = substr($0, RSTART + 1, RLENGTH - 1)
 100             style = ext2style[ext]
 101             reset = ext2reset[ext]
 102 
 103             if (style == "") {
 104                 style = palette[n++ % c]
 105                 reset = "\x1b[0m" style
 106                 ext2style[ext] = style
 107                 ext2reset[ext] = reset
 108             }
 109 
 110             gsub(/\x1b\[0m/, reset)
 111             printf "%s%s\x1b[0m\n", style, $0
 112             if (flush) fflush()
 113             next
 114         }
 115 
 116         print
 117         if (flush) fflush()
 118     }
 119 ' "$@"