File: limit.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 # limit [options...] [max bytes...] [files...]
  27 #
  28 # Limit output to only the first n given bytes, using the leading number given,
  29 # or the first 1024 bytes by default. This is just a more intuitive alternative
  30 # to using the basic command `head -c`.
  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 "$1" in
  38     -h|--h|-help|--help)
  39         awk '/^# +limit /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  40         exit 0
  41     ;;
  42 
  43     --) ;;
  44 
  45     -*)
  46         printf "unsupported option '%s'\n" "$1" >&2
  47         exit 1
  48     ;;
  49 esac
  50 
  51 bytes=1024
  52 if echo "$1" | grep -q -E '^\+?[0-9]+$'; then
  53     bytes="$1" && shift
  54 fi
  55 
  56 [ "$1" = '--' ] && shift
  57 
  58 head -c "${bytes}" "$@"