File: lines.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 # lines [options...] [files...]
  27 #
  28 # Unlike `cat`, this tool guarantees no lines across inputs are accidentally
  29 # joined, since all lines it outputs end with line-feeds, even when the
  30 # original files don't.
  31 #
  32 # The options are, available both in single and double-dash versions
  33 #
  34 #   -h, -help    show this help message
  35 #   -0, -null    turn null-byte-delimited chunks into proper lines
  36 
  37 
  38 nulled=0
  39 
  40 case "$1" in
  41     -h|--h|-help|--help)
  42         awk '/^# +lines /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  43         exit 0
  44     ;;
  45 
  46     -0|--0|-null|--null)
  47         nulled=1
  48         shift
  49     ;;
  50 esac
  51 
  52 [ "$1" = '--' ] && shift
  53 
  54 flush=0
  55 if [ -p /dev/stdout ] || [ -t 1 ]; then
  56     flush=1
  57 fi
  58 
  59 # show all non-existing files given
  60 failed=0
  61 for arg in "$@"; do
  62     if [ "${arg}" = "-" ]; then
  63         continue
  64     fi
  65     if [ ! -e "${arg}" ]; then
  66         printf "no file named \"%s\"\n" "${arg}" >&2
  67         failed=1
  68     fi
  69 done
  70 
  71 if [ "${failed}" -gt 0 ]; then
  72     exit 2
  73 fi
  74 
  75 if [ "${nulled}" -eq 0 ]; then
  76     awk -v flush="${flush}" '{ print; if (flush) fflush() }' "$@"
  77 else
  78     awk -v RS='\000' -v flush="${flush}" '{ print; if (flush) fflush() }' "$@"
  79 fi