File: vrt.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 # vrt [option...] [files...]
  27 #
  28 # View Rich Text is a simple non-interactive plain-text file viewer, which
  29 # handles ANSI-codes and renders pictures out of data-URI lines.
  30 #
  31 # The options are, available in single and double-dashed versions
  32 #
  33 #   -h, -help     show this help message
  34 #   -header=n     always show first `n` lines at the top
  35 #   -n, -N        show line numbers for overall results
  36 #   -s, -sixel    show pictures using the sixel format (experimental)
  37 #   -t, -top      always show first line at the top
  38 
  39 
  40 case "$1" in
  41     -h|--h|-help|--help)
  42         awk '/^# +vrt /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  43         exit 0
  44     ;;
  45 esac
  46 
  47 width=0
  48 sixels=0
  49 # less_options='-MKiCRS'
  50 less_options='-MKiCS'
  51 
  52 while [ $# -gt 0 ]; do
  53     if [ "$1" = '--' ]; then
  54         shift
  55         break
  56     fi
  57 
  58     case "$1" in
  59         -n|--n|-N|--N)
  60             less_options="${less_options} -N"
  61             shift
  62             continue
  63         ;;
  64 
  65         --header=*)
  66             less_options="${less_options} $1"
  67             shift
  68             continue
  69         ;;
  70 
  71         -s|--s|-sixel|--sixel|-sixels|--sixels)
  72             sixels=1
  73             # less_options="${less_options} -r"
  74             shift
  75             continue
  76         ;;
  77 
  78         -t|--t|-top|--top)
  79             less_options="${less_options} --header=1"
  80             shift
  81             continue
  82         ;;
  83 
  84         -w|--w|-width|--width)
  85             shift
  86             if [ $# -eq 0 ]; then
  87                 printf "expected number after width option\n" >&2
  88                 exit 1
  89             fi
  90             width="$1"
  91             shift
  92             continue
  93         ;;
  94     esac
  95 
  96     break
  97 done
  98 
  99 if [ "${sixels}" -eq 0 ]; then
 100     less_options="${less_options} -R"
 101 fi
 102 
 103 if [ "${width}" -eq 0 ]; then
 104     width="$(tput -T xterm cols)"
 105 fi
 106 
 107 if [ $# -eq 0 ]; then
 108     less ${less_options} -f -
 109     exit $?
 110 fi
 111 
 112 if [ $# -lt 2 ]; then
 113     less_options="${less_options} --header=1"
 114 fi
 115 
 116 # show all non-existing files given
 117 failed=0
 118 for arg in "$@"; do
 119     [ "${arg}" = "-" ] && continue
 120     [ -e "${arg}" ] && continue
 121     printf "no file named \"%s\"\n" "${arg}" >&2
 122     failed=1
 123 done
 124 
 125 [ "${failed}" -gt 0 ] && exit 2
 126 
 127 view_pic=''
 128 if [ -e /usr/bin/chafa ]; then
 129     view_pic='chafa'
 130     if [ "${sixels}" -eq 1 ]; then
 131         view_pic='chafa --format sixels'
 132     fi
 133 fi
 134 
 135 awk -v width="${width}" -v view_pic="${view_pic}" '
 136     BEGIN {
 137         if (width >= 170) width = (width - 10) / 2
 138         fmt = "sh -c \"base64 -d | %s --size %dx\""
 139         render_pic_cmd = sprintf(fmt, view_pic, width)
 140     }
 141 
 142     FNR == 1 {
 143         if (files++ > 0) print ""
 144         printf "\x1b[7m%-80s\x1b[0m\n", FILENAME
 145     }
 146 
 147     { gsub(/\r$/, "") }
 148 
 149     /^data:image\/[a-z]+;base64,[A-Za-z0-9/+]*=*$/ {
 150         if (view_pic == "") {
 151             print "image renderer \"chafa\" not found" > "/dev/stderr"
 152             exit 1
 153         }
 154 
 155         gsub(/^data:image\/[a-z]+;base64,/, "")
 156         print | render_pic_cmd
 157         close(render_pic_cmd)
 158         next
 159     }
 160 
 161     # { print; next }
 162 
 163     /\t/ { print; next }
 164 
 165     {
 166         pos = 0
 167 
 168         for (i = 1; i <= NF; i++) {
 169             plain = $i
 170             gsub(/\x1b\[[0-9;]*[A-Za-z]/, "", plain)
 171             w = length(plain) + (i > 1)
 172 
 173             if (pos + w >= width || w >= width) {
 174                 print ""
 175                 pos = 0
 176             }
 177 
 178             pos += w
 179 
 180             if (i == 1) printf "%s", $i
 181             else printf " %s", $i
 182         }
 183 
 184         if (pos > 0 || NF == 0) print ""
 185     }
 186 ' "$@" | less ${less_options}