CODEWITHSUNDEEP
bashassociative-array
yab
yab

Reputation: 113

bash find keyword in an associative array

I have incoming messages from a chat server that need to be compared against a list of keywords. I was using regular arrays, but would like to switch to associative arrays to try to increase the speed of the processing.

The list of words would be in an array called aWords and the values would be a 'type' indicator, i.e. aWords[damn]="1", with 1 being swear word in a legend to inform the user.

The issue is that I need to compare every index value with the input $line looking for substrings. I'm trying to avoid a loop thru each index value if at all possible.

From http://tldp.org/LDP/abs/html/string-manipulation.html, I'm thinking of the Substring Removal section.

${string#substring}
Deletes shortest match of $substring from front of $string.

A comparison of the 'removed' string from the $line, may help, but will it match also words in the middle of other words? i.e. matching the keyword his inside of this.

Sorry for the long-winded post, but I tried to cover all of what I'm attempting to accomplish as best I could.

Upvotes: 2

Views: 322

Answers (2)

thom
thom

Reputation: 2332

This is the first time I heard of associative arrays in bash. It inspired me to also try to add something, with the chance ofcourse that I completely miss the point.

Here is a code snippet. I hope I understood how it works:

declare -A SWEAR       #create associative array of swearwords (only once)
while read LINE
do
        [ "$LINE"] && SWEAR["$LINE"]=X
done < "/path/to/swearword/file"


while : 
do
    OUTGOING=""        #reset output "buffer"
    read REST          #read a sentence from stdin
    while "$REST"      #evaluate every word in the sentence
    do
        WORD=${REST%% *}
        REST=${REST#* }
        [ ${SWEAR[$WORD]} ] && WORD="XXXX"
        OUTGOING="$OUTGOING $WORD"
    done
    echo "$OUTGOING"    #output to stdout
done

Upvotes: 0

glenn jackman
glenn jackman

Reputation: 246847

# create a colon-separated string of the array keys
# you can do this once, after the array is created.
keys=$(IFS=:; echo "${!aWords[*]}")

if [[ ":$keys:" == *:"$word":* ]]; then
    # $word is a key in the array
    case ${aWords[$word]} in
        1) echo "Tsk tsk: $word is a swear word" ;;
        # ...
    esac
fi

Upvotes: 1

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