How do you append to an already existing string?

user_138541 0
Viewed 287041

I want append to a string so that every time I loop over it, it will add "test" to the string.

Like in PHP you would do:

$teststr = "test1\n"
$teststr .= "test2\n"
echo = "$teststr"

Returns:

test1
test2

But I need to do this in a shell script

string-concatenation shell bash string
7 Answers

In classic sh, you have to do something like:

s=test1
s="${s}test2"

(there are lots of variations on that theme, like s="$s""test2")

In bash, you can use +=:

s=test1
s+=test2
user_1407500 
$ string="test"
$ string="${string}test2"
$ echo $string
testtest2
user_1315270 
#!/bin/bash
message="some text"
message="$message add some more"

echo $message

some text add some more

user_2739030 
teststr=$'test1\n'
teststr+=$'test2\n'
echo "$teststr"
Ignacio_Vazquez-Abrams_208620

thank-you Ignacio Vazquez-Abrams

i adapted slightly for better ease of use :)

placed at top of script

NEW_LINE=$'\n'

then to use easily with other variables

variable1="test1"
variable2="test2"

DESCRIPTION="$variable1$NEW_LINE$variable2$NEW_LINE"

OR to append thank-you William Pursell

DESCRIPTION="$variable1$NEW_LINE"
DESCRIPTION+="$variable2$NEW_LINE"

echo "$DESCRIPTION"
user_140230510
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