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FalcoGer
Asked: 2021-09-01 08:56:13 +0800 CST

bash concatenate string in loop results in empty string

  • 772

I have the following file

Hello
World
my
name
is
FalcoGer

And I wish to concatenate the strings of each line.

I wrote the following script to do just that.

#! /usr/bin/bash
myFile=/home/FalcoGer/testfile.txt

result=""
cat $myFile | while read line
do
  result+="$line "
done

echo Result: $result

However I only get Result: with an empty string. When I print it from within the loop it seems to work just fine. What's wrong with this script and how do I fix it?

bash

1 Answers

  1. Best Answer

    Using the pipe essentially creates a new script with a new scope. You can avoid the pipe like so:

    #! /usr/bin/bash
myFile=/home/FalcoGer/testfile.txt

result=""
while read -r line
do
  result+="$line "
done < $myFile

echo Result: $result
    • 4