CODEWITHSUNDEEP
bashsed
Earlz
Earlz

Reputation: 63885

How to append text to a word in a multiline file in bash

So someone on twitter mentioned this. You have a text file like so:

watermelon
taco
bacon
cheese

You want to append the text "kitten" to the end of "taco". Thus, the wanted output is as so:

watermelon
tacokitten
bacon
cheese

How can you do this in bash?

Upvotes: 0

Views: 244

Answers (3)

felipsmartins
felipsmartins

Reputation: 13549

Explicitly:

TARGET_FILE=/path/to/file.txt
LINENO=1 # line number counter
NEEDLE="taco"

for word in $(cat $TARGET_FILE)
do     
    if [ "$word" = $NEEDLE ]
    then
        #echo "Appending $word on line $LINENO..."
        sed -i "${LINENO}s/.*/${word}TEXTAPPENDED/" $TARGET_FILE
        break
    fi   
    LINENO=$(( LINENO +1 )) #increase line number by 1  
done

Upvotes: 0

Kevin
Kevin

Reputation: 56129

While sed is clearly a better choice, academically, here's how to do it in pure bash (or zsh):

while read line; do
    if [ "$line" = "taco" ]; then 
        line=${line}kitten
    fi
    echo "$line"
done < test.in

Or slightly more idiomatically:

while read line; do
    [ "$line" = "taco" ] && line=${line}kitten 
    echo "$line" 
done < test.in

Or in awk:

awk '/^taco$/{$0=$0"kitten"}1' test.in

Upvotes: 1

user142162
user142162

Reputation:

There's nothing bash specific about this; just use the sed program:

sed 's/^\(taco\)$/\1kitten/' inputfile

Upvotes: 3

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