Bash programming — how to add string into text file

Question

touch log.txt
while [ 1 ]; do 
 echo "insert data: "
 read data
 if [ $data = "finish" ]; then
  break
 fi
 echo "$data" >> log.txt

When I run the program and type in a word in an input like "hello im martin", it gives me an error saying unexpected operator. How to fix this?

@FernandoAires: the script wouldn't get as far as running to get the input and then fail on the 'unexpected operator' if the done was missing. — Jonathan Leffler
– Jonathan Leffler, Commented Sep 20, 2014 at 7:03

tophyr · Accepted Answer · 2014-09-20 06:53:41Z

3

You're missing a done keyword after your echo statement that signifies the end of the while loop.

Additionally, you should put the $data on line 5 in quotes, otherwise the hello im martin input will cause that line to be interpreted as:

if [ hello im martin = "finish" ]; then

answered Sep 20, 2014 at 6:53

tophyr

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1 Comment

And, in Bash, the other option is to use the [[ … ]] operator to do the comparison.

Sudhanshu Sharma · Accepted Answer · 2014-09-20 10:59:21Z

0

Try this

while [ 1 ]; do

echo "insert data:"; read data

if [ "$data" == "finish" ]; then

break;

fi

echo "$data" >> log.txt;

done

answered Sep 20, 2014 at 10:59

Sudhanshu Sharma

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