Perl regex to extract floating number

Question

I need to modify someone\'s Perl script, and I am not familiar with Perl at all.

There is a scalar variable $var, whose value is a floating point number pos

Answer 1

Following your update, the expression you need is:

^\d+(?:\.\d+)?

• ^\d+ Match digits at start of string.
• (?: Start of non capturing group.
• \.\d+ Match a literal ., followed by digits.
• )? Close non capturing group making it optional.

Check the expression here.

A Perl example:

$var = "123.456.789";
print "old $var\n";
$var =~ /(^\d+(?:\.\d+)?)/;
print "new $1\n";

Prints:

old 123.456.789
new 123.456