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 options are, available both in single and double-dash versions
  34 #
  35 #   -h, -help    show this help message
  36 #   -i, -ins     compare lines case-insensitively
  37 
  38 
  39 
  40 insensitive=0
  41 case "$1" in
  42     -h|--h|-help|--help)
  43         awk '/^# +cbe /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  44         exit 0
  45     ;;
  46 
  47     -i|--i|-ins|--ins|-insensitive|--insensitive)
  48         insensitive=1
  49         shift
  50     ;;
  51 
  52     -) ;;
  53 
  54     --) shift ;;
  55 
  56     -*)
  57         printf "unsupported option '%s'\n" "$1" >&2
  58         exit 1
  59     ;;
  60 esac
  61 
  62 # show all non-existing files given
  63 failed=0
  64 for arg in "$@"; do
  65     [ "${arg}" = "-" ] && continue
  66     [ -e "${arg}" ] && continue
  67     printf "no file named \"%s\"\n" "${arg}" >&2
  68     failed=1
  69 done
  70 
  71 [ "${failed}" -gt 0 ] && exit 2
  72 
  73 flush=0
  74 if [ -p /dev/stdout ] || [ -t 1 ]; then
  75     flush=1
  76 fi
  77 
  78 awk -v flush="${flush}" -v ci="${insensitive}" '
  79     BEGIN {
  80         if (ci && IGNORECASE == "") {
  81             msg = "this variant of AWK lacks case-insensitive regex-matching"
  82             print(msg) > "/dev/stderr"
  83             exit 125
  84         }
  85         if (ci) IGNORECASE = 1
  86 
  87         palette[c++] = "\x1b[48;2;0;95;215m\x1b[38;2;238;238;238m" # blue
  88         palette[c++] = "\x1b[48;2;215;95;0m\x1b[38;2;238;238;238m" # orange
  89         palette[c++] = "\x1b[48;2;135;95;255m\x1b[38;2;238;238;238m" # purple
  90         palette[c++] = "\x1b[48;2;0;175;215m\x1b[38;2;238;238;238m" # cyan
  91         palette[c++] = "\x1b[48;2;255;135;255m\x1b[38;2;238;238;238m" # pink
  92         palette[c++] = "\x1b[48;2;0;135;95m\x1b[38;2;238;238;238m" # green
  93         palette[c++] = "\x1b[48;2;204;0;0m\x1b[38;2;238;238;238m" # red
  94         palette[c++] = "\x1b[48;2;168;168;168m\x1b[38;2;238;238;238m" # gray
  95     }
  96 
  97     {
  98         gsub(/\r$/, "")
  99 
 100         # ignore cursor-movers and style-changers
 101         # gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")
 102 
 103         if (match($0, /\.[A-Za-z][A-Za-z0-9_-]*/)) {
 104             ext = substr($0, RSTART + 1, RLENGTH - 1)
 105             style = ext2style[ext]
 106             reset = ext2reset[ext]
 107 
 108             if (style == "") {
 109                 style = palette[n++ % c]
 110                 reset = "\x1b[0m" style
 111                 ext2style[ext] = style
 112                 ext2reset[ext] = reset
 113             }
 114 
 115             gsub(/\x1b\[0m/, reset)
 116             printf "%s%s\x1b[0m\n", style, $0
 117             if (flush) fflush()
 118             next
 119         }
 120 
 121         print
 122         if (flush) fflush()
 123     }
 124 ' "$@"