How to make regex accept strings with a dot - regex

Question

I'm currently debugging a Perl script and encountered some errors which will be described in the following sections below:
In the script, I have this -td variable designed to accept a string like 1n, 5n, 0.3n, 0.8n
But when I try to use the the last two from the said list, the script does not work as intended, and only works fine when I use only the first two from the list.
To give you an overview, I have written some portions of the script, then after the code, I will state my concern:
if (scalar(#ARGV) < 1){ &get_usage() };
# Getoptions Setup ##
GetOptions (
'h|help' => \$help,
'v|version' => \$version,
'i|input=s' => \$input,
'o|output=s' => \$output,
... # more options here
'td=s' => \$td_val, # this is the line in question
'val=s' => \$v_var,
... # more options here
) or die get_usage(); # this will only call usage of script or help
... # more codes here
get_input_arg(); # this function will validate the entries user had inputted
#assigning to a placeholder value for creating a new file
$td_char="\ttd=$td_val" if $td_val;
$td_char=" " if !$td_val;
... # fast forward ...
sub get_input_arg{
...
# here you go, there is wrong in the following regex to accept values such as 0.8n
unless (($td_val=~/^\d+(m|u|n|p)s$/)||($td_val=~/^\d+(m|u|n|p|s)$/)||($td_val=~/^\d+$/)){#
print "\n-td error!\nEnter the required value!\n";
get_usage();
... # more functions here ...
}
For explanation:
On the console user will input -td 5n
The 5n will be assigned to td_val and to td_char and be used for printing later
This 5n will be validated by get_input_arg() function which will pass to the regex unless line.
For 5n input, script work as intended, but when we use -td 0.8n, then after validating it, it will print the error message after the unless line on the console
I know the regex is failing on matching with regards to using 0.8n as td input, but I don't know how can I fix it. Thanks in advance!

Answer 1

You can use
unless (($td_val=~/^\d+(\.\d+)?[munp]s$/)||($td_val=~/^\d+(\.\d+)?[munps]$/)||($td_val=~/^\d+(\.\d+)?$/))
Explanation:
Your regex has \d+ which matches only integers.. so replace it with \d+(\.\d+)? (integral part followed by optional decimal part)
See DEMO