examples/scripts.noah/y_or_n_p.bash

   1 # y_or_n_p.bash
   2 # Author: Noah Friedman <friedman@prep.ai.mit.edu>
   3 # Created: 1992-06-18
   4 # Last modified: 1993-03-01
   5 # Public domain
   6
   7 # Conversion to bash v2 syntax done by Chet Ramey
   8
   9 # Commentary:
  10 # Code:
  11
  12 #:docstring y_or_n_p:
  13 # Usage: y_or_n_p QUERY
  14 #
  15 # Print QUERY on stderr, then read stdin for a y-or-n response.  Actually,
  16 # user may type anything they like, but first character must be a `y', `n',
  17 # `q', or `!', otherwise the question is repeated until such an answer is
  18 # obtained.
  19 #
  20 # If user typed `y', y_or_n_p returns 0.
  21 #
  22 # If user typed `n', y_or_n_p returns 1.
  23 #
  24 # If user typed `!', y_or_n_p returns 2.  This is an indication to the
  25 #  caller that no more queries should be made.  Assume `y' for all the rest.
  26 #
  27 # If user typed `q', y_or_n_p returns 3.  This is an indication to the
  28 #  caller that no more queries should be made.  Assume `n' for all the rest.
  29 #
  30 #:end docstring:
  31
  32 ###;;;autoload
  33 function y_or_n_p ()
  34 {
  35  local ans
  36
  37     [ ! -t 0 ] && return 1
  38
  39     while read -p "$*" -e ans ; do
  40         case "${ans}" in
  41         y* | Y* ) return 0 ;;
  42         n* | N* ) return 1 ;;
  43         \! )      return 2 ;;
  44         q* | Q* ) return 3 ;;
  45         *) echo "Please answer one of \`y', \`n', \`q', or \`"\!"'" 1>&2 ;;
  46         esac
  47    done
  48 }
  49
  50 #:docstring yes_or_no_p:
  51 # Usage: yes_or_no_p QUERY
  52 #
  53 # Like y_or_n_p, but require a full `yes', `no', `yes!', or `quit' response.
  54 #:end docstring:
  55
  56 ###;;;autoload
  57 function yes_or_no_p ()
  58 {
  59     local ans
  60
  61     [ ! -t 0 ] && return 3
  62
  63     while read -p "$*" -e ans; do
  64         ans="$(echo ${ans} | tr '[A-Z]' '[a-z]')"
  65
  66         case "${ans}" in
  67         yes )   return 0 ;;
  68         no )    return 1 ;;
  69         yes\! ) return 2 ;;
  70         quit )  return 3 ;;
  71         *) echo "Please answer \`yes', \`no', \`yes"\!"', or \`quit'" 1>&2 ;;
  72        esac
  73    done
  74 }
  75
  76 provide y_or_n_p
  77
  78 # y_or_n_p.bash ends here