File: ierase.awk
   1 #!/usr/bin/awk -f
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright © 2020-2025 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 # ierase [regular expressions...]
  27 #
  28 # Ignore/remove all case-insensitively matched regexes given on all stdin
  29 # lines. When not given any regex, remove trailing spaces/carriage-returns.
  30 
  31 
  32 BEGIN {
  33     if (IGNORECASE == "") {
  34         msg = "this variant of AWK lacks case-insensitive regex-matching"
  35         printf("\x1b[31m%s\x1b[0m\n", msg) > "/dev/stderr"
  36         exit 125
  37     }
  38     IGNORECASE = 1
  39 
  40     if (ARGC < 2) {
  41         ARGC = 2
  42         ARGV[1] = " *\r?$"
  43     }
  44 
  45     for (i = 1; i < ARGC; i++) {
  46         re[i] = ARGV[i]
  47         delete ARGV[i]
  48     }
  49 }
  50 
  51 {
  52     for (i = 1; i < ARGC; i++) gsub(re[i], "")
  53     print; fflush()
  54 }