File: n.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 # n [options...] [start...] [files...]
  27 #
  28 # Number all lines starting at 1, or at the optional number given as the first
  29 # argument. In the output, leading line numbers and line contents are separated
  30 # by a tab.
  31 #
  32 # The options are, available both in single and double-dash versions
  33 #
  34 #    -h, -help    show this help message
  35 
  36 
  37 buffered=0
  38 
  39 case "$1" in
  40     -b|--b|-buffered|--buffered) buffered=1; shift ;;
  41 
  42     -h|--h|-help|--help)
  43         awk '/^# +n /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  44         exit 0
  45     ;;
  46 esac
  47 
  48 start=1
  49 if echo "$1" | grep -E -q '^[+-]?[0-9]+$'; then
  50     start="$1" && shift
  51 else
  52     case "$1" in
  53         --) shift ;;
  54 
  55         -*)
  56             printf "unsupported option '%s'\n" "$1" >&2
  57             exit 1
  58         ;;
  59     esac
  60 fi
  61 
  62 # show all non-existing files given
  63 failed=0
  64 for arg in "$@"; do
  65     [ "${arg}" = "-" ] && continue
  66     [ -e "${arg}" ] && continue
  67     printf "no file named \"%s\"\n" "${arg}" >&2
  68     failed=1
  69 done
  70 
  71 [ "${failed}" -gt 0 ] && exit 2
  72 
  73 flush=0
  74 if [ "${buffered}" -eq 0 ] && { [ -p /dev/stdout ] || [ -t 1 ]; }; then
  75     flush=1
  76 fi
  77 
  78 src='{ printf("%d\t%s\n", n++, $0); if (flush) fflush() }'
  79 
  80 awk -v flush="${flush}" -v n="${start}" "${src}" "$@"