File: hima.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 # hima [options...] [regexes...]
  27 #
  28 #
  29 # HIlight MAtches ANSI-styles matching regular expressions along lines read
  30 # from the standard input. The regular-expression mode used is a superset of
  31 # the commonly-used "extended-mode".
  32 #
  33 # All ANSI-style sequences from stdin are removed, to avoid messing those up:
  34 # the only ANSI styles left in the output will be from the matches, if any.
  35 #
  36 # Also, multiple matches in a line never overlap: at each step along a line,
  37 # the earliest-starting match among the regexes always wins, as the order
  38 # regexes are given among the arguments never matters.
  39 #
  40 # The options are, available both in single and double-dash versions
  41 #
  42 #     -h, -help      show this help message
  43 #     -f, -filter    filter out (ignore) lines with no matches
  44 #     -i, -ins       match regexes case-insensitively
  45 
  46 
  47 filter=0
  48 case_insensitive=0
  49 
  50 for arg in "$@"; do
  51     if [ "${arg}" = '--' ]; then
  52         shift
  53         break
  54     fi
  55 
  56     case "$1" in
  57         -f|--f|-filter|--filter)
  58             filter=1
  59             shift
  60             continue
  61         ;;
  62 
  63         -h|--h|-help|--help)
  64             awk '/^# +hima /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  65             exit 0
  66         ;;
  67 
  68         -i|--i|-ins|--ins)
  69             case_insensitive=1
  70             shift
  71             continue
  72         ;;
  73     esac
  74 
  75     break
  76 done
  77 
  78 [ "$1" = '--' ] && shift
  79 
  80 command='awk'
  81 if { [ -p /dev/stdout ] || [ -t 1 ]; } && [ -e /usr/bin/stdbuf ]; then
  82     command='stdbuf -oL awk'
  83 fi
  84 
  85 ci='
  86     BEGIN {
  87         if (IGNORECASE == "") {
  88             m = "your `awk` command lacks case-insensitive regex-matching"
  89             print(m) > "/dev/stderr"
  90             exit 125
  91         }
  92         IGNORECASE = 1
  93     }
  94 '
  95 if [ "${case_insensitive}" -eq 0 ]; then
  96     ci=''
  97 fi
  98 
  99 expr="$(awk '
 100     BEGIN {
 101         for (i = 1; i < ARGC; i++) {
 102             if (i > 1) printf "|"
 103             printf "(%s)", ARGV[i]
 104         }
 105         exit
 106     }
 107 ' "$@")"
 108 
 109 ${command} -v expr="${expr}" -v filter="${filter}" "${ci}"'
 110     {
 111         # ignore cursor-movers and style-changers
 112         gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")
 113 
 114         # ignore OSC sequences
 115         gsub(/\x1b\][^\x1b]+\x1b\\/, "")
 116 
 117         if (filter && $0 !~ expr) next
 118 
 119         gsub(expr, "\x1b[7m&\x1b[0m")
 120         print
 121     }
 122 '