fortune

   1 #!/usr/bin/sh -e
   2 # Fortune implementation in POSIX sh/awk
   3
   4 usage() {
   5                 echo 'Usage: fortune [OPTIONS]
   6 a simple POSIX sh/awk implementation of fortune
   7
   8         -h, --help                    show this help message
   9         -l, --list                    list installed cookie files
  10         -c FILE, --cookie FILE        specify cookie file
  11         -n LENGTH, --min LENGTH       specify min fortune length
  12         -N LENGTH, --max LENGTH       specify max fortune length
  13
  14         fortune looks for fortunes in $FORTUNEDIR, which defaults to
  15         /usr/share/fortune.
  16
  17 Exit codes:
  18         0    success
  19         1    generic error
  20         2    argument parsing error'
  21 }
  22
  23 parse_err() {
  24                 echo "$1"
  25                 $2
  26                 exit 2
  27 }
  28
  29 DIR=${FORTUNEDIR:-"/usr/share/fortune/"}
  30 FILE="$(find $DIR -type f -not -name '*.dat')"
  31 MAXLENGTH=1000000000000
  32 MINLENGTH=0
  33
  34 while [ "$1" != "" ]; do
  35                 case $1 in
  36                                 -h | --help)
  37                                                 usage
  38                                                 exit
  39                                                 ;;
  40                                 -c | --cookie)
  41                                                 FILE=$DIR/$2
  42                                                 ;;
  43                                 -n | --min)
  44                                                 MINLENGTH=$2
  45                                                 ;;
  46                                 -N | --max)
  47                                                 MAXLENGTH=$2
  48                                                 ;;
  49                                 -l | --list)
  50                                                 ls -1 $DIR
  51                                                 exit
  52                                                 ;;
  53                                 *)
  54                                                 parse_err "ERROR: unknown option \"$1\"" usage
  55                                                 ;;
  56                 esac
  57                 shift 2
  58 done
  59
  60 [ "$MAXLENGTH" -lt "$MINLENGTH" ] && {
  61                 parse_err "ERROR: maximum length is less than minimum length"
  62 }
  63
  64 [ -d "$FILE" ] && {
  65                 parse_err "ERROR: directory given, please provide a file or glob of files"
  66 }
  67
  68 [ "$(find $FILE -maxdepth 1 -print -quit 2> /dev/null)" ] || {
  69                 parse_err "ERROR: no such file or directory"
  70 }
  71
  72 awk -v maxlen=$MAXLENGTH -v minlen=$MINLENGTH \
  73                 'BEGIN {
  74         f++
  75 }
  76
  77 $1 == "%" {
  78         len = length(fortunes[f])
  79         if ( len>maxlen || len<minlen ) {
  80                 fortunes[f] = ""
  81         } else {
  82                 f++
  83         }
  84 }
  85
  86 {
  87         sub("%", "")
  88         fortunes[f] = fortunes[f] (length(fortunes[f])?"\n":"") $0
  89 }
  90
  91 END {
  92         "od -A n -t d -N 3 /dev/urandom" | getline seed
  93         srand(seed)
  94         print fortunes[int(rand() * (f - 2)) + 1]
  95 }' $FILE