File: cawk.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 # cawk [options...] [awk condition...] [files...]
  27 #
  28 #
  29 # Count with AWK: count the times the AWK expression/condition given is true.
  30 #
  31 # When not given an expression, records (by default lines) are counted. A `.`
  32 # (no quotes) for the expression also enables the default behavior.
  33 #
  34 # The handy case-insensitive shortcut options may cause this tool to fail,
  35 # if the main `awk` tool installed doesn't support the special `IGNORECASE`
  36 # variable.
  37 #
  38 # The AWK options available only in single-dash versions are
  39 #
  40 #   -F fs, -Ffs, -F=fs    make `fs` the field separator
  41 #
  42 # The other options are, available both in single and double-dash versions
  43 #
  44 #   -h, -help    show this help message
  45 #   -i, -ins     match regexes case-insensitively; may fail `awk`
  46 #   -tsv         split fields using tabs, same as using -F "\t"
  47 
  48 
  49 tsv=0
  50 ins=0
  51 command='awk'
  52 
  53 while [ $# -gt 0 ]; do
  54     case "$1" in
  55         -F)
  56             if [ $# -lt 2 ]; then
  57                 printf "%s: expected value after -F option\n" "$0" >&2
  58                 exit 1
  59             fi
  60             command="${command} -F $2"; shift 2; continue
  61         ;;
  62 
  63         -F*) command="${command} $1"; shift; continue ;;
  64 
  65         -h|--h|-help|--help)
  66             awk '/^# +cawk /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  67             exit 0
  68         ;;
  69 
  70         -i|--i|-ins|--ins|-insensitive|--insensitive) ins=1; shift; continue ;;
  71 
  72         -tsv|--tsv) tsv=1; shift; continue ;;
  73 
  74         -v)
  75             if [ $# -lt 2 ]; then
  76                 printf "%s: missing variable assignment after -v option\n" \
  77                     "$0" >&2
  78                 exit 1
  79             fi
  80             command="${command} -v $1"; shift 2; continue
  81         ;;
  82 
  83         -) break ;;
  84 
  85         --) shift; break ;;
  86 
  87         -*)
  88             printf "%s: unsupported option %s\n" "$0" "$1" >&2
  89             exit 1
  90         ;;
  91     esac
  92 
  93     break
  94 done
  95 
  96 cond="${1:-1}"
  97 [ $# -gt 0 ] && shift
  98 if [ "${cond}" = '.' ]; then
  99     cond=1
 100 fi
 101 
 102 # show all non-existing files given
 103 failed=0
 104 for arg in "$@"; do
 105     [ "${arg}" = '-' ] && continue
 106     [ -e "${arg}" ] && continue
 107     printf "%s: no file named \"%s\"\n" "$0" "${arg}" >&2
 108     failed=1
 109 done
 110 
 111 [ "${failed}" -gt 0 ] && exit 2
 112 
 113 ci='
 114     BEGIN {
 115         if (IGNORECASE == "") {
 116             m = "your `awk` command lacks case-insensitive regex-matching"
 117             print(m) > "/dev/stderr"
 118             exit 125
 119         }
 120         IGNORECASE = 1
 121     }
 122 '
 123 if [ "${ins}" -eq 0 ]; then
 124     ci=''
 125 fi
 126 
 127 src="${ci}"'
 128     BEGIN { N = C = COUNT = 0 }
 129     ('"${cond}"') { N = C = ++COUNT }
 130     END { print(COUNT + 0) }
 131 '
 132 
 133 if [ "${tsv}" -eq 1 ]; then
 134     ${command} -F "\t" "${src}" "$@"
 135 else
 136     ${command} "${src}" "$@"
 137 fi