File: v.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 # v [options...] [files...]
  27 #
  28 # View, which runs `less -~MKiCRS`, gives you an interactive text viewer
  29 # with both horizontal and vertical scrolling, line numbers, ANSI-code
  30 # support for styled/colored text, and case-insensitive regex search.
  31 #
  32 # If `less` is a symbolic-link, it's assumed to point to `busybox`, and
  33 # (for compatibility) `less -~RIMS` is run instead.
  34 #
  35 # The options are, available both in single and double-dash versions
  36 #
  37 #   -h, -help            show this help message
  38 #   --header=N           always show first N lines on top; may fail
  39 #   -n, -N               automatically show line numbers
  40 #   -sticky, -t, -top    same as option `--header=1`; may fail
  41 
  42 
  43 # busybox's `less` doesn't support the options `-C` and `-K`
  44 if [ -L less ]; then
  45     options='-~RIMS'
  46 else
  47     options='-~MKiCRS'
  48 fi
  49 
  50 while [ $# -gt 0 ]; do
  51     case "$1" in
  52         -f|--f) options="${options} -f"; shift; continue ;;
  53 
  54         -h|--h|-help|--help)
  55             awk '/^# +v /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  56             exit 0
  57         ;;
  58 
  59         --header=*) options="${options} $1"; shift; continue ;;
  60 
  61         -n|-N) options="${options} -N"; shift; continue ;;
  62 
  63         -sticky|--sticky|-t|--t|-top|--top)
  64             options="${options} --header=1"; shift; continue
  65         ;;
  66 
  67         -) break ;;
  68 
  69         --) shift; break ;;
  70 
  71         -*)
  72             printf "%s: unsupported option %s\n" "$0" "$1" >&2
  73             exit 1
  74         ;;
  75     esac
  76 
  77     break
  78 done
  79 
  80 if [ $# -gt 0 ] || [ -p /dev/stdin ]; then
  81     less ${options} "$@"
  82 else
  83     awk '/^# +v /, /^$/ { gsub(/^# ?/, ""); print }' "$0" >&2
  84     exit 1
  85 fi