File: pawk.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 # pawk [options...] [awk expression] [files...]
  27 #
  28 # Print AWK expression for each input line: this is a convenient shortcut,
  29 # to type less when using AWK.
  30 #
  31 # The options are, available both in single and double-dash versions
  32 #
  33 #   -h, -help             show this help message
  34 #   -ins, -insensitive    match regexes case-insensitively; fail if unsupported
  35 #   -tsv                  tab-separated values: split input fields using tabs
  36 
  37 
  38 case "$1" in
  39     -h|--h|-help|--help)
  40         awk '/^# +pawk /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  41         exit 0
  42     ;;
  43 esac
  44 
  45 command='awk'
  46 if { [ -p /dev/stdout ] || [ -t 1 ]; } && [ -e /usr/bin/stdbuf ]; then
  47     command='stdbuf -oL awk'
  48 fi
  49 
  50 tsv=0
  51 case_insensitive=0
  52 
  53 while [ $# -gt 0 ]; do
  54     arg="$1"
  55 
  56     if [ "${arg}" = "--" ]; then
  57         shift
  58         break
  59     fi
  60 
  61     case "${arg}" in
  62         -F)
  63             shift
  64             if [ $# -eq 0 ]; then
  65                 printf "expected value after -F option\n" >&2
  66                 exit 1
  67             fi
  68             command="${command} -F $1"
  69             shift
  70             continue
  71         ;;
  72 
  73         -F*)
  74             command="${command} ${arg}"
  75             shift
  76             continue
  77         ;;
  78 
  79         -v)
  80             shift
  81             if [ $# -eq 0 ]; then
  82                 printf "expected variable assignment after -v option\n" >&2
  83                 exit 1
  84             fi
  85             command="${command} -v $1"
  86             shift
  87             continue
  88         ;;
  89 
  90         -ins|--ins|-insensitive|--insensitive)
  91             case_insensitive=1
  92             shift
  93             continue
  94         ;;
  95 
  96         -tsv|--tsv)
  97             tsv=1
  98             shift
  99             continue
 100         ;;
 101 
 102         -*)
 103             command="${command} ${arg}"
 104             shift
 105             continue
 106         ;;
 107     esac
 108 
 109     break
 110 done
 111 
 112 expr="${1:-\$0}"
 113 [ $# -gt 0 ] && shift
 114 
 115 # show all non-existing files given
 116 failed=0
 117 for arg in "$@"; do
 118     if [ "${arg}" = "-" ]; then
 119         continue
 120     fi
 121     if [ ! -e "${arg}" ]; then
 122         printf "no file named \"%s\"\n" "${arg}" > /dev/stderr
 123         failed=1
 124     fi
 125 done
 126 
 127 if [ "${failed}" -gt 0 ]; then
 128     exit 2
 129 fi
 130 
 131 src='
 132     BEGIN {
 133         if (IGNORECASE == "") {
 134             m = "your `awk` command lacks case-insensitive regex-matching"
 135             print(m) > "/dev/stderr"
 136             exit 125
 137         }
 138         IGNORECASE = 1
 139     }
 140 
 141     { print ('"${expr}"') }
 142 '
 143 
 144 if [ "${case_insensitive}" -eq 0 ]; then
 145     src='{ print ('"${expr}"') }'
 146 fi
 147 
 148 if [ "${tsv}" -eq 1 ]; then
 149     ${command} -F "\t" -v OFS="\t" "${src}" "$@"
 150 else
 151     ${command} "${src}" "$@"
 152 fi