Monday, 28 January 2013

Spell checker and corrector in BASH

Why? Because it can be done.

I have used nothing but BASH.

Sample run:

I tried to make it very feature rich while keeping code to about 100 lines - this version is about 80.

Can you make it smaller?

* Auto-corrects if it can only find 1 suggested correction.
* Lists all words in dictionary that could be corrections and lets user choose or replace word.
* Suggestions only consider words with single letter deletions, additions or changes.
* Spelling errors are highlighted in yellow.
* Corrections are highlighted in green.

* Save result to a file (Currently just displays result on terminal).

I did go a little overboard with processing word case.


[[ -z "$1" ]] && echo "Usage: $0 " && exit 1
ERR=33; COR=32                                   # error and corrected colours
PS3="Select or manually enter a correction: "
L="a-zA-Z'"                                      # these letters are deemed part of words
shopt -s extglob
shopt -u nocasematch
declare -A WORD
while read W; do WORD[${W,,}]=${W,,}; done < /usr/share/dict/words

function checkSuggestion() {
    local p=$1 S=$1 C                            # uses CASE and SUGGEST from caller
    [ -z "${WORD[$p]}" ] && return 1             # matches word in dict!
    [ $CASE = PROP  ] && S=${p^}                 # change case to original word
    [ $CASE = CAP   ] && S=${p^^}   
    [ $CASE = CAPs  ] && { S=${p%%\'*};             S="${S^^}'${p#*\'}"; }   
    [ $CASE = LAT   ] && { S=${p##*\'};             S="${p%\'*}'${S^^}"; }   
    [ $CASE = OPROP ] && { S=${p%%\'*}; C=${p#*\'}; S="${S^^}'${C^}";    }   
    SUGGEST="${SUGGEST/ $S /} $S "               # add to suggestion list

function getSuggestions() {
    local W=$1 t l # p
    [[ $W =~ ^[A-Z][a-z]        ]] && CASE=PROP   # Prop
    [[ $W =~ ^[A-Z][A-Z]        ]] && CASE=CAP    # CAP
    [[ $W =~ ^[A-Z]\'[a-z]      ]] && CASE=PROP   # P'rop
    [[ $W =~  [A-Z]\'[a-z]$     ]] && CASE=CAPs   # CAP's
    [[ $W =~ ^[a-z]\'[A-Z]      ]] && CASE=LAT    # l'At
    [[ $W =~ ^[A-Z]\'[A-Z][A-Z] ]] && CASE=CAP    # C'AP
    [[ $W =~ ^[A-Z]\'[A-Z][a-z] ]] && CASE=OPROP  # O'Prop
    W=${W,,}                                     # lowercase word
    for (( t=0 ; t<=${#W} ; t++ )); do           # for each letter position of word, delete|change|insert a letter
        checkSuggestion ${W:0:t}${W:t+1}         # try deleting letter at position t
        for l in {a..z} "'"; do                  # try changing and inserting letters
            checkSuggestion ${W:0:t}$l${W:t+1}   # try changing letter
            checkSuggestion ${W:0:t}$l${W:t}     # try inserting letter

function correctWord() {                         # correct word and return in RET as well as pattern in PAT
    local W=$1 D1 D2 SUGGEST                     # uses L RESULT
        getSuggestions "$W"
        [[ ! "$RESULT" =~ ([^$L]|^)$W([^$L]|$) ]] && { printf "ERROR: Could not find [%s] in %s\n" "$W" "$LINE"; exit 1; }
        D1="${BASH_REMATCH[1]}"; D2="${BASH_REMATCH[2]}"  # get delimiters around word
        PAT="${D1:-#}$W${D2:-%}"                 # match pattern
        case $SUGGEST in
             '') echo -e "${RESULT/$PAT/$D1\e[${ERR}m$W\e[0m$D2}"   # display line with spelling mistake highlighted
                 read -p "Enter correction [$W]: " RET < /dev/fd/3  # no suggestions - let user correct
            +([$L ])\ +([$L ]))                                     # multiple suggestions
                 echo -e "${RESULT/$PAT/$D1\e[${ERR}m$W\e[0m$D2}"   # display line with spelling mistake highlighted
                 select RET in "(IGNORE)" $SUGGEST; do              # get correction
                     RET=${RET:-$REPLY}                             # user entered a word instead
                     [ "$REPLY" = "1" ] && RET=$W                   # no change
                 done < /dev/fd/3;;
              *) RET=${SUGGEST// /}                                 # get single suggestion
                 printf "%b\n" "\e[31mAuto:\e[0m ${RESULT/$PAT/$D1\e[9;${ERR}m$W\e[0;${COR}m $RET\e[0m$D2}"
        COL=$COR; [ "$RET" = "$W" ] && COL=$ERR   # if unchanged, highlight in error colour
        RESULT="${RESULT/$PAT/$D1\e[${COL}m${RET}\e[0m$D2}"       # correct word

function correctLine(){
    local LINE="$1" W                            # uses RESULT
    while read -d' ' W; do                       # for each word in line
        [[ -z "$W" || -n ${WORD[${W,,}]} ]] 2> /dev/null && continue  # null or word in dict so ignore it
        correctWord $W
        printf ">> %b\n\n" "$RESULT" 
    done <<< "$LINE"

while read LINE; do  # for each line
    correctLine " ${LINE//[^$L ]/ } "            # replace punctuation with spaces
    FINAL+="$RESULT\n"                           # append corrected line to result
done 3<&0 < $1                                   # redirect stdin to /dev/fd/3 for select and read

printf "\nCORRECTED TEXT\n\n%b\n" "$FINAL"

Tuesday, 22 January 2013

Replacing Ford NL Fairlane Power Steering Nut

Based on advice from fordmods, I purchased a BA 3F656B Nut from Ford. $17.

It looks like this one from ebay:

My original one looks very different - like this one:

I cut two grooves on opposite sides into my old nut using a ruby cutting blade and a Dremel.

I cut carefully using nut's internal rubber seal groove as a guide. Once I cut into this groove, I stopped cutting. I didn't cut deep enough to reach the other groove.

With a length of hardwood resting on concrete floor and cut to length, we used a cold chisel to crack nut in half. We were chiselling on hex part rather than on thread.

After a few hits it split.

My original nut had a small white nylon seal. New nut did not have anything like that so I installed a thin rubber o-ring - couldn't hurt I reasoned.

New nut just slides on to hose and clicks in place.

This is my new nut installed. The blue 'cape' is used to keep drips away from alternator.

Friday, 18 January 2013

How to Import Birthdays and Anniversaries into Google Calendar

This is a quick bash script I made that reads a file of events and creates an ical file suitable for importing into Google Calendar.

Date file supports these event formats:

day/month event description
day/month/year event description

Brief Instructions

1. Cut and paste program into a text file.

2. Save file as pc-ssv-to-ical.bash (or whatever you like)

3. In a terminal, chmod +x pc-ssv-to-ical.bash

4. Make an event file (eg. special dates) lile this:
1/1 New Year
26/1 Australia Day
4/4/1914 Someon'es Birthday
5/5/1915 Bill/Jill Wedding (1915)

5. Run ./pc-ssv-to-ical.bash special.dates > cal-import.ics 
6. Import cal-import.ics into a Google Calendar



#    This script takes events from a file and outputs in ical format 
#    suitable for importing into a Google Calendar.
#    Copyright (C) 2013  phil colbourn
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    GNU General Public License for more details.
#    A copy of the GNU General Public License can be obtained from
#    .


shopt -s extglob

# load special dates as day/month[/year] event description
# eg. 1/5/2004 A Person of Interest
# eg. 24/5 Not Sure When Born

# use this to convert SSV to CVS
# cat special-dates.ssv | sed 's/ /,/' > special-dates.csv



while read DATE EVENT; do
    [[ -z $DATE ]] && continue               # ignore null dates
    # D/M[/Y] format
    D="0${DATE%%/*}"                         # get day part
    D="${D: -2}"   
    M="${DATE#*/}"                           # get month part
    M="${M: -2}"
    # M/D[/Y] format
    #M="0${DATE%%/*}"                         # get month part
    #M="${M: -2}"   
    #D="${DATE#*/}"                           # get day part
    #D="${D: -2}"
    Y="${DATE/[0-9]?([0-9])[\/][0-9]?([0-9])/}"  # get year part
    Y=${Y//[\/]/}                            # remove left over /
    [[ -z $Y ]] && Y=$( date +%Y )           # use this year if none given

cat <

done < $SSV

printf "END:VCALENDAR\n"

unset IFS


1. Code could be simplified if a more strict date format was used. eg. DD/MM[/YYYY]
2. Code will need to be changed for M/D[/Y] dates.
3. Space separated (SSV) and CSV formats both work. Quoted and double-quoted events also seem to work.