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 help option is `-h`, `--h`, `-help`, or `--help`.
  33 
  34 
  35 case "$1" in
  36     -h|--h|-help|--help)
  37         awk '/^# +cext /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  38         exit 0
  39     ;;
  40 esac
  41 
  42 [ "$1" = '--' ] && shift
  43 
  44 # show all non-existing files given
  45 failed=0
  46 for arg in "$@"; do
  47     if [ "${arg}" = "-" ]; then
  48         continue
  49     fi
  50     if [ ! -e "${arg}" ]; then
  51         printf "no file named \"%s\"\n" "${arg}" >&2
  52         failed=1
  53     fi
  54 done
  55 
  56 if [ "${failed}" -gt 0 ]; then
  57     exit 2
  58 fi
  59 
  60 flush=0
  61 if [ -p /dev/stdout ] || [ -t 1 ]; then
  62     flush=1
  63 fi
  64 
  65 awk -v flush="${flush}" '
  66     BEGIN {
  67         palette[c++] = "\x1b[38;2;0;95;215m" # blue
  68         palette[c++] = "\x1b[38;2;215;95;0m" # orange
  69         palette[c++] = "\x1b[38;2;135;95;255m" # purple
  70         palette[c++] = "\x1b[38;2;0;175;215m" # cyan
  71         palette[c++] = "\x1b[38;2;255;135;255m" # pink
  72         palette[c++] = "\x1b[38;2;0;135;95m" # green
  73         palette[c++] = "\x1b[38;2;204;0;0m" # red
  74         palette[c++] = "\x1b[38;2;168;168;168m" # gray
  75     }
  76 
  77     {
  78         gsub(/\r$/, "")
  79 
  80         # ignore cursor-movers and style-changers
  81         # gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")
  82 
  83         rest = $0
  84 
  85         while (match(rest, /\.[A-Za-z][A-Za-z0-9_-]*/)) {
  86             printf "%s", substr(rest, 1, RSTART - 1)
  87 
  88             ext = substr(rest, RSTART, RLENGTH)
  89             rest = substr(rest, RSTART + RLENGTH)
  90 
  91             style = ext2style[ext]
  92             if (style == "") {
  93                 style = palette[n++ % c]
  94                 ext2style[ext] = style
  95             }
  96 
  97             printf "%s%s\x1b[0m", style, ext
  98         }
  99 
 100         print rest
 101         if (flush) fflush()
 102     }
 103 ' "$@"