How do I preserve newlines in a quoted string in Bash? [duplicate]

Question

I'm creating a script to automate the creation of apache virtual hosts. Part of my script goes like this:

MYSTRING="<VirtualHost *:80>

ServerName $NEWVHOST
DocumentRoot /var/www/hosts/$NEWVHOST

...

"
echo $MYSTRING

However, the line breaks in the script are being ignored. If I echo the string, is gets spat out as one line.

How can I ensure that the line breaks are printed?

Jihad

Answer 1

Add quotes to make it work:

echo "$MYSTRING"

Look at it this way:

MYSTRING="line-1
line-2
line3"

echo $MYSTRING

this will be executed as:

echo line-1 \
line-2 \
line-3

i.e. echo with three parameters, printing each parameter with a space in between them.

If you add quotes around $MYSTRING, the resulting command will be:

echo "line-1
line-2
line-3"

i.e. echo with a single string parameter which has three lines of text and two line breaks.

Parthinia

Thanks, now I finally understand why echo works like this - because it parses the input as arguments! I wish I read that somewhere earlier. – Ryley

Tangentially, see also #10067766 – Fluorine