How can I delete perl regex lines?

Question

when i run:

perl -e '$x="abc\nxyz\n123"; $x =~ s/\n.*/... multiline.../; printf("str %s\n", $x);'

I expect the result to be as follows:

str abc... multiline...

instead i get

str abc... multiline...
123

Where am I going wrong?

Answer 1

$x =~ s/\n.*/... multiline.../s

Modifier

/stells Perl to treat the matched string as single-line, which results in .matching newlines. This usually does not lead to observable behavior.

Answer 2

You need to use the 's' modifier for your regular expression, so dot '.' will match any subsequent newline. So:

$x =~ s/\n.*/... multiline.../;

Becomes as follows:

$x =~ s/\n.*/... multiline.../s;