File: cext.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 # cext [options...] [files...]
  27 #
  28 # Color/style file EXTensions makes all file-extensions stand out, using
  29 # different ANSI-styles as it finds new ones. Since its list of styles is
  30 # limited, these will start being reused, given enough unique extensions.
  31 #
  32 # The options are, available both in single and double-dash versions
  33 #
  34 #   -h, -help    show this help message
  35 
  36 
  37 case "$1" in
  38     -h|--h|-help|--help)
  39         awk '/^# +cext /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  40         exit 0
  41     ;;
  42 
  43     -) ;;
  44 
  45     --) shift ;;
  46 
  47     -*)
  48         printf "unsupported option '%s'\n" "$1" >&2
  49         exit 1
  50     ;;
  51 esac
  52 
  53 # show all non-existing files given
  54 failed=0
  55 for arg in "$@"; do
  56     [ "${arg}" = "-" ] && continue
  57     [ -e "${arg}" ] && continue
  58     printf "no file named \"%s\"\n" "${arg}" >&2
  59     failed=1
  60 done
  61 
  62 [ "${failed}" -gt 0 ] && exit 2
  63 
  64 flush=0
  65 if [ -p /dev/stdout ] || [ -t 1 ]; then
  66     flush=1
  67 fi
  68 
  69 awk -v flush="${flush}" '
  70     BEGIN {
  71         palette[c++] = "\x1b[38;2;0;95;215m" # blue
  72         palette[c++] = "\x1b[38;2;215;95;0m" # orange
  73         palette[c++] = "\x1b[38;2;135;95;255m" # purple
  74         palette[c++] = "\x1b[38;2;0;175;215m" # cyan
  75         palette[c++] = "\x1b[38;2;255;135;255m" # pink
  76         palette[c++] = "\x1b[38;2;0;135;95m" # green
  77         palette[c++] = "\x1b[38;2;204;0;0m" # red
  78         palette[c++] = "\x1b[38;2;168;168;168m" # gray
  79     }
  80 
  81     {
  82         gsub(/\r$/, "")
  83 
  84         # ignore cursor-movers and style-changers
  85         # gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")
  86 
  87         rest = $0
  88 
  89         while (match(rest, /\.[A-Za-z][A-Za-z0-9_-]*/)) {
  90             printf "%s", substr(rest, 1, RSTART - 1)
  91 
  92             ext = substr(rest, RSTART, RLENGTH)
  93             rest = substr(rest, RSTART + RLENGTH)
  94 
  95             style = ext2style[ext]
  96             if (style == "") {
  97                 style = palette[n++ % c]
  98                 ext2style[ext] = style
  99             }
 100 
 101             printf "%s%s\x1b[0m", style, ext
 102         }
 103 
 104         print rest
 105         if (flush) fflush()
 106     }
 107 ' "$@"