igor@4: #!/bin/bash
igor@4: 
igor@4: LANGUAGE=en
igor@4: N=50
igor@4: REVERSED=NO
igor@4: 
igor@4: show_usage()
igor@4: {
igor@4:     cat<<USAGE > /dev/stderr
igor@4: 
igor@4: Usage:
igor@4:     $0 [ -l LANG ] [ -r ] [ N ]
igor@4: 
igor@4: Help to learn N (number) previously marked words from LANG language.
igor@4: 
igor@4: Options:
igor@4:     -r  reversed mode (show the note first; the word second)
igor@4: 
igor@4: By default:
igor@4: 
igor@4:     LANG     =  $LANGUAGE
igor@4:     N        =  $N
igor@4:     REVERSED =  $REVERSED
igor@4: 
igor@4: USAGE
igor@4: }
igor@4: 
igor@4: if [ "$1" = -l ]
igor@4: then  
igor@4:     if [ -n "$2" ]
igor@4:     then
igor@4:         LANGUAGE="$2"
igor@4:         shift 2
igor@4:     else 
igor@4:         echo "Error: Please, specify LANGUAGE (en, de, ru,...) after -l or don't use -l switch" > /dev/stderr
igor@4:         show_usage
igor@4:         exit 1
igor@4:     fi
igor@4: fi
igor@4: 
igor@4: if [ "$1" = -r ]
igor@4: then  
igor@4:     REVERSED="YES"
igor@4:     shift
igor@4: fi
igor@4: 
igor@4: if [ -n "$1" ]
igor@4: then
igor@4:     if echo "$1" | grep -qx '[0-9]\+'
igor@4:     then
igor@4:         N="$1"
igor@4:     else
igor@4:         echo "Error: Number of words N should be numeric. " > /dev/stderr
igor@4:         echo "       Please provide a number or don't specify N at all " > /dev/stderr
igor@4:         show_usage
igor@4:         exit 1
igor@4:     fi
igor@4: fi
igor@4: 
igor@4: notes_file=~/".new-words/notes-$LANGUAGE".txt
igor@4: if [ -e $notes_file ]
igor@4: then
igor@4:     true
igor@4:     number="`wc -l $notes_file | awk '{print $1}'`"
igor@4:     if [ "$number" -lt "$N" ]
igor@4:     then
igor@4:         echo "Warning: The notes file for the language is too short. Truncating N to $number" > /dev/stderr
igor@4:         N="$number"
igor@4:     fi
igor@4:     while true
igor@4:     do
igor@4:         main_script="$$"
igor@4:         tail -n $((1+$RANDOM%$N)) $notes_file | head -1 | while read word note
igor@4:         do
igor@4:             trap "kill -1 $main_script; kill -1 $$" 2
igor@4:             if [ "$REVERSED" = "NO" ]
igor@4:             then 
igor@4:                 echo $word
igor@4:                 read < /dev/tty
igor@4:                 echo $note
igor@4:                 read < /dev/tty
igor@4:                 clear
igor@4:             else
igor@4:                 echo $note
igor@4:                 read < /dev/tty
igor@4:                 echo $word
igor@4:                 read < /dev/tty
igor@4:                 clear
igor@4:             fi
igor@4:         done
igor@4:     done
igor@4: else
igor@4:     echo "Error: Uknown language '$LANGUAGE'" > /dev/stderr
igor@4:     echo "       File $notes_file not found" > /dev/stderr
igor@4:     exit 1
igor@4: fi